Advertisement

Comparison of Inhospital Mortality, Length of Hospitalization, Costs, and Vascular Complications of Percutaneous Coronary Interventions Guided by Ultrasound Versus Angiography

Published:February 19, 2015DOI:https://doi.org/10.1016/j.amjcard.2015.02.037
      Despite the valuable role of intravascular ultrasound (IVUS) guidance in percutaneous coronary interventions (PCIs), its impact on clinical outcomes remains debatable. The aim of the present study was to compare the outcomes of PCIs guided by IVUS versus angiography in the contemporary era on inhospital outcomes in an unrestricted large, nationwide patient population. Data were obtained from the Nationwide Inpatient Sample from 2008 to 2011. Hierarchical mixed-effects logistic regression models were used for categorical dependent variables like inhospital mortality, and hierarchical mixed-effects linear regression models were used for continuous dependent variables like length of hospital stay and cost of hospitalization. A total of 401,571 PCIs were identified, of which 377,096 were angiography guided and 24,475 (weighted n = 119,102) used IVUS. In a multivariate model, significant predictors of higher mortality were increasing age, female gender, higher baseline co-morbidity burden, presence of acute myocardial infarction, shock, weekend and emergent admission, or occurrence of any complication during hospitalization. Significant predictors of reduced mortality were the use of IVUS guidance (odds ratio 0.65, 95% confidence interval 0.52 to 0.83; p <0.001) for PCI and higher hospital volumes (third and fourth quartiles). The use of IVUS was also associated with reduced inhospital mortality in subgroup of patients with acute myocardial infarction and/or shock and those with a higher co-morbidity burden (Charlson's co-morbidity index ≥2). In one of the largest studies on IVUS-guided PCIs in the drug-eluting stent era, we demonstrate that IVUS guidance is associated with reduced inhospital mortality, similar length of hospital stay, and increased cost of care and vascular complications compared with conventional angiography-guided PCIs.
      Intravascular ultrasound (IVUS), secondary to its excellent spatial resolution, provides valuable complementary information to angiography on cross-sectional coronary anatomy and plaque burden and composition. Furthermore, IVUS guidance is useful in selecting appropriate treatment strategy, stent sizing, and optimal deployment, especially in complex lesions. Despite the valuable role of IVUS guidance in percutaneous coronary interventions (PCIs), its impact on clinical outcomes remains controversial. The initial studies performed in the bare-metal stent (BMS) era demonstrated that IVUS-guided PCI significantly reduced the risk of restenosis and target vessel revascularization with no effect on mortality and myocardial infarction (MI).
      • Casella G.
      • Klauss V.
      • Ottani F.
      • Siebert U.
      • Sangiorgio P.
      • Bracchetti D.
      Impact of intravascular ultrasound-guided stenting on long-term clinical outcome: a meta-analysis of available studies comparing intravascular ultrasound-guided and angiographically guided stenting.
      • Parise H.
      • Maehara A.
      • Stone G.W.
      • Leon M.B.
      • Mintz G.S.
      Meta-analysis of randomized studies comparing intravascular ultrasound versus angiographic guidance of percutaneous coronary intervention in pre-drug-eluting stent era.
      However, the studies evaluating IVUS-guided PCI in the drug-eluting stent (DES) era are limited and have yielded conflicting results. Additionally, most studies have been underpowered to detect meaningful differences in clinical outcomes with IVUS-guided PCI. However, there is recent evidence that suggests IVUS-guided PCI in the DES era may significantly reduce the risk of death and stent thrombosis compared with angiography guidance.
      • Jakabcin J.
      • Spacek R.
      • Bystron M.
      • Kvasnak M.
      • Jager J.
      • Veselka J.
      • Kala P.
      • Cervinka P.
      Long-term health outcome and mortality evaluation after invasive coronary treatment using drug eluting stents with or without the IVUS guidance. Randomized control trial. HOME DES IVUS.
      • Chieffo A.
      • Latib A.
      • Caussin C.
      • Presbitero P.
      • Galli S.
      • Menozzi A.
      • Varbella F.
      • Mauri F.
      • Valgimigli M.
      • Arampatzis C.
      • Sabate M.
      • Erglis A.
      • Reimers B.
      • Airoldi F.
      • Laine M.
      • Palop R.L.
      • Mikhail G.
      • Maccarthy P.
      • Romeo F.
      • Colombo A.
      A prospective, randomized trial of intravascular-ultrasound guided compared to angiography guided stent implantation in complex coronary lesions: the AVIO trial.
      • Zhang Y.
      • Farooq V.
      • Garcia-Garcia H.M.
      • Bourantas C.V.
      • Tian N.
      • Dong S.
      • Li M.
      • Yang S.
      • Serruys P.W.
      • Chen S.L.
      Comparison of intravascular ultrasound versus angiography-guided drug-eluting stent implantation: a meta-analysis of one randomised trial and ten observational studies involving 19,619 patients.
      • Witzenbichler B.
      • Maehara A.
      • Weisz G.
      • Neumann F.J.
      • Rinaldi M.J.
      • Metzger D.C.
      • Henry T.D.
      • Cox D.A.
      • Duffy P.L.
      • Brodie B.R.
      • Stuckey T.D.
      • Mazzaferri Jr., E.L.
      • Xu K.
      • Parise H.
      • Mehran R.
      • Mintz G.S.
      • Stone G.W.
      Relationship between intravascular ultrasound guidance and clinical outcomes after drug-eluting stents: the assessment of dual antiplatelet therapy with drug-eluting stents (ADAPT-DES) study.
      • Ahn J.M.
      • Kang S.J.
      • Yoon S.H.
      • Park H.W.
      • Kang S.M.
      • Lee J.Y.
      • Lee S.W.
      • Kim Y.H.
      • Lee C.W.
      • Park S.W.
      • Mintz G.S.
      • Park S.J.
      Meta-analysis of outcomes after intravascular ultrasound-guided versus angiography-guided drug-eluting stent implantation in 26,503 patients enrolled in three randomized trials and 14 observational studies.
      • Dattilo P.B.
      • Prasad A.
      • Honeycutt E.
      • Wang T.Y.
      • Messenger J.C.
      Contemporary patterns of fractional flow reserve and intravascular ultrasound use among patients undergoing percutaneous coronary intervention in the United States: insights from the National Cardiovascular Data Registry.
      The aim of the present study was to compare the outcome PCIs guided by IVUS versus those guided by angiography in the contemporary era on inhospital outcomes in an unrestricted large, nationwide patient population.

      Methods

      Data were obtained from the Nationwide Inpatient Sample (NIS). NIS is a part of a family of databases developed for the Healthcare Cost and Utilization Project and is sponsored by the Agency for Healthcare Research and Quality (AHRQ). NIS contains all discharge data from >1,000 short-term and non-Federal hospitals each year, which approximates a 20% stratified sample of US community hospitals. Data from the NIS have previously been used to identify, track, and analyze national trends in health care use, patterns of major procedures, access, disparity of care, trends in hospitalizations, charges, quality, and outcomes.
      • Kumar G.
      • Kumar N.
      • Taneja A.
      • Kaleekal T.
      • Tarima S.
      • McGinley E.
      • Jimenez E.
      • Mohan A.
      • Khan R.A.
      • Whittle J.
      • Jacobs E.
      • Nanchal R.
      Nationwide trends of severe sepsis in the 21st century (2000-2007).
      • Deshmukh A.
      • Kumar G.
      • Kumar N.
      • Nanchal R.
      • Gobal F.
      • Sakhuja A.
      • Mehta J.L.
      Effect of Joint National Committee VII report on hospitalizations for hypertensive emergencies in the United States.
      • Deshmukh A.
      • Patel N.J.
      • Pant S.
      • Shah N.
      • Chothani A.
      • Mehta K.
      • Grover P.
      • Singh V.
      • Vallurupalli S.
      • Savani G.T.
      • Badheka A.
      • Tuliani T.
      • Dabhadkar K.
      • Dibu G.
      • Reddy Y.M.
      • Sewani A.
      • Kowalski M.
      • Mitrani R.
      • Paydak H.
      • Viles-Gonzalez J.F.
      In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.
      • Patel N.J.
      • Deshmukh A.
      • Pant S.
      • Singh V.
      • Patel N.
      • Arora S.
      • Shah N.
      • Chothani A.
      • Savani G.T.
      • Mehta K.
      • Parikh V.
      • Rathod A.
      • Badheka A.O.
      • Lafferty J.
      • Kowalski M.
      • Mehta J.L.
      • Mitrani R.D.
      • Viles-Gonzalez J.F.
      • Paydak H.
      Trends of hospitalization for atrial fibrillation in the United States, 2000 through 2010: implications for healthcare planning.
      • Badheka A.O.
      • Patel N.J.
      • Singh V.
      • Shah N.
      • Chothani A.
      • Mehta K.
      • Deshmukh A.
      • Ghatak A.
      • Rathod A.
      • Desai H.
      • Savani G.T.
      • Grover P.
      • Patel N.
      • Arora S.
      • Grines C.L.
      • Schreiber T.
      • Makkar R.
      • Rihal C.S.
      • Cohen M.G.
      • De Marchena E.
      • O'Neill W.W.
      Percutaneous aortic balloon valvotomy in the US: a 13 years perspective.
      • Badheka A.O.
      • Shah N.
      • Ghatak A.
      • Patel N.J.
      • Chothani A.
      • Mehta K.
      • Patel N.
      • Singh V.
      • Grover P.
      • Deshmukh A.
      • Panaich S.S.
      • Savani G.T.
      • Bhalara V.
      • Arora S.
      • Rathod A.
      • Desai H.
      • Kar S.
      • Alfonso C.
      • Palacios I.F.
      • Grines C.
      • Schreiber T.
      • Rihal C.S.
      • Makkar R.
      • Cohen M.G.
      • O'Neill W.
      • de Marchena E.
      Balloon mitral valvuloplasty in United States: a 13 year perspective.
      Annual data quality assessments are performed for internal validity of the database. To maintain the external validity, database is compared with the following data sources: the American Hospital Association Annual Survey Database, the National Hospital Discharge Survey from the National Center for Health Statistics, and the MedPAR inpatient data from the Centers for Medicare and Medicaid Services.
      • Zipes D.P.
      • Wellens H.J.
      Sudden cardiac death.
      We analyzed data from NIS from 2008 to 2011 using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes of 36.06 for non–drug-eluting coronary artery stents and 36.07 for drug-eluting coronary artery stents in any of the procedural fields. Subjects ≥18 years were included. PCIs performed under IVUS guidance were identified by ICD-9-CM code 00.24. We excluded PCIs with fractional flow reserve guidance (ICD-9-CM: 00.59) or where both fractional flow reserve and IVUS were used. The remaining observations were categorized as angiography-guided (AO) PCIs.
      We defined severity of co-morbid conditions using Deyo modification of Charlson's co-morbidity index (CCI).
      • McDonald K.M.
      • Romano P.S.
      • Geppert J.
      • Davies S.M.
      • Duncan B.W.
      • Shojania K.G.
      • Hansen A.
      Measures of Patient Safety Based on Hospital Administrative Data—The Patient Safety Indicators.
      This index contains 17 co-morbid conditions with differential weights. The score ranges from 0 to 33, with higher scores corresponding to greater burden of co-morbid diseases (Supplementary Table 1). Hospitals were categorized as teaching if they had an American Medical Association–approved residency program, were a member of the Council of Teaching Hospitals, or had a full-time equivalent interns and resident-to-patient ratio of ≥0.25. Annual hospital volume was determined on a year-to-year basis using the unique hospital identification number to calculate the total number of procedures performed by a particular institution in a given year.
      The primary outcome was all-cause inhospital mortality. Procedural complications were identified by Patient Safety Indicators (PSIs), version 4.4, March 2012, which have been established by the AHRQ to monitor preventable adverse events during hospitalization. These indicators are based on ICD-9-CM codes and Medicare severity diagnosis-related groups, and each PSI has specific inclusion and exclusion criteria.
      • McDonald K.M.
      • Romano P.S.
      • Geppert J.
      • Davies S.M.
      • Duncan B.W.
      • Shojania K.G.
      • Hansen A.
      Measures of Patient Safety Based on Hospital Administrative Data—The Patient Safety Indicators.
      • Romano P.S.
      • Geppert J.J.
      • Davies S.
      • Miller M.R.
      • Elixhauser A.
      • McDonald K.M.
      A national profile of patient safety in U.S. hospitals.
      Procedural complications not included in PSI were identified using ICD-9-CM codes (Supplementary Table 2). This methodology of identifying patients who underwent procedures, co-morbid conditions, and associated complications has previously been used in several studies.
      • Deshmukh A.
      • Patel N.J.
      • Pant S.
      • Shah N.
      • Chothani A.
      • Mehta K.
      • Grover P.
      • Singh V.
      • Vallurupalli S.
      • Savani G.T.
      • Badheka A.
      • Tuliani T.
      • Dabhadkar K.
      • Dibu G.
      • Reddy Y.M.
      • Sewani A.
      • Kowalski M.
      • Mitrani R.
      • Paydak H.
      • Viles-Gonzalez J.F.
      In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.
      • Badheka A.O.
      • Patel N.J.
      • Singh V.
      • Shah N.
      • Chothani A.
      • Mehta K.
      • Deshmukh A.
      • Ghatak A.
      • Rathod A.
      • Desai H.
      • Savani G.T.
      • Grover P.
      • Patel N.
      • Arora S.
      • Grines C.L.
      • Schreiber T.
      • Makkar R.
      • Rihal C.S.
      • Cohen M.G.
      • De Marchena E.
      • O'Neill W.W.
      Percutaneous aortic balloon valvotomy in the US: a 13 years perspective.
      Other outcomes studied were the length of hospital stay (LOS) and cost of hospitalization. LOS included admissions with observational and inpatient status. To estimate the cost of hospitalization, the NIS data were merged with cost-to-charge ratios available from the Healthcare Cost and Utilization Project. We estimated the cost of each inpatient stay by multiplying the total hospital charge with cost-to-charge ratios. Adjusted cost for each year was calculated in terms of the 2011 cost, after adjusting for inflation according to the latest consumer price index data released by the US government on January 16, 2013.
      • Jan S.L.
      • Shieh G.
      Sample size determinations for Welch's test in one-way heteroscedastic ANOVA.
      • Greenland S.
      Dose-response and trend analysis in epidemiology: alternatives to categorical analysis.
      Stata IC 11.0 (Stata-Corp, College Station, Texas) and SAS 9.3 (SAS Institute Inc., Cary, North Carolina) were used for analyses, which accounted for the complex survey design and clustering. All analyses were performed using hospital-level discharge weights provided by the NIS to minimize biases.
      Hierarchical mixed-effects models were generated to identify the independent multivariate predictors of inhospital mortality, LOS, and cost of hospitalization. Three-level hierarchical models (with patient-level factors nested within hospital-level factors) were created with the unique hospital identification number incorporated as random effects within the model. Subgroup analysis was also performed in subgroup of patients with acute myocardial infarction (AMI) and/or shock and those with Charlson's co-morbidity index ≥2.
      We used propensity-scoring method to establish matched cohorts to control for imbalances of patient and hospital characteristics between the 2 different treatment groups that may have influenced treatment outcome. A propensity score was assigned to each hospitalization. This was based on multivariate logistic regression model that examined the impact of 12 variables (patient demographics, co-morbidities, and hospital characteristics) on the likelihood of treatment assignment. Patients with similar propensity score in the 2 treatment groups were matched using a 1 to 1 scheme without replacement using greedy algorithm.
      • Badheka A.O.
      • Arora S.
      • Panaich S.S.
      • Patel N.J.
      • Patel N.
      • Chothani A.
      • Mehta K.
      • Deshmukh A.
      • Singh V.
      • Savani G.T.
      • Agnihotri K.
      • Grover P.
      • Lahewala S.
      • Patel A.
      • Bambhroliya C.
      • Kondur A.
      • Brown M.
      • Elder M.
      • Kaki A.
      • Mohammad T.
      • Grines C.
      • Schreiber T.
      Impact on in-hospital outcomes with drug-eluting stents versus bare-metal stents (from 665,804 procedures).
      Variables with >10% missing data (such as race) were not included in the multivariate models. All interactions were thoroughly tested. Collinearity was assessed using variance inflation factor.

      Results

      A total of 401,571 PCIs were identified, of which 377,096 were AO PCIs and 24,475 used IVUS (IVUS PCIs). Table 1 demonstrates the baseline characteristics of the study population. The mean age of the study population was 64.3 ± 0.02 years with majority (88%) of the patients >50 years; 66% were men and 65% were whites. There were significant differences between the baseline characteristics of the 2 groups (Table 1). More patients in the AO PCI group had CCI score ≥2, diabetes, AMI, low household income (less than twenty-fifth percentile), emergent admissions, weekend admissions, and use of BMS, whereas IVUS PCIs outnumbered in patients with hypertension, high household income (more than seventy-fifth percentile), elective admissions, weekday admissions, multivessel stenting, bifurcation stenting, multiple stents in a single vessel, and use of DES. DES was implanted in nearly 73.5% of the PCIs in this study population.
      Table 1Baseline characteristics of the studied population
      Demographic variableAngiography guided PCIIVUS guided PCIOverallP-value
      Total no. of PCI (Unweighted NO.)377,09624,475401,571
      Total no. of PCI (weighted no.)18,594,82119,10219,785,84
      Patient level variables
      Age(Continuous Variable)64.3±0.0264.1±0.0864.3±0.010.012
      Age (years)<0.001
      18-340.60.60.6
      35-4911.911.211.8
      50-6438.038.538.1
      65-7937.038.837.1
      ≥8012.610.912.5
      Gender<0.001
      Male66.464.566.3
      Female33.635.533.7
      Race
      Race was missing in 18% of the study population and hence excluded in the multivariable analysis.
      <0.001
      White64.966.265.0
      Non-white16.617.816.7
      Missing18.416.118.3
      Charlson/Deyo comorbidity index
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      <0.001
      018.725.319.1
      139.437.639.3
      ≥241.937.141.6
      Comorbidities
      Variables are AHRQ comorbidity measures.
      Obesity13.413.913.5<0.001
      History of hypertension72.173.772.2<0.001
      History of diabetes34.032.834.0<0.001
      History of congestive heart failure0.50.40.50.489
      History of chronic pulmonary disease15.715.515.70.106
      Peripheral vascular disease10.610.510.60.743
      Renal failure16.916.416.9<0.001
      Neurological disorder or paralysis3.63.33.6<0.001
      Anemia or Coagulopathy8.78.58.70.028
      Hematological or Oncological malignancy1.51.51.50.125
      Weight loss0.60.60.60.221
      Rheumatoid arthritis or other collagen vascular disease1.91.91.90.174
      Depression, psychosis or substance abuse8.58.98.5<0.001
      Median household income category for patient's zip code
      This represents a quartile classification of the estimated median household income of residents in the patient's ZIP Code. These values are derived from ZIP Code-demographic data obtained from Claritas. The quartiles are identified by values of 1 to 4, indicating the poorest to wealthiest populations. Because these estimates are updated annually, the value ranges vary by year. http://www.hcupus.ahrq.gov/db/vars/zipinc_qrtl/nisnote.jsp.
      <0.001
      1. 0-25th percentile27.124.426.9
      2. 26-50th percentile27.625.327.5
      3. 51-75th percentile24.024.324.0
      4. 76-100th percentile19.123.819.4
      Primary Payer<0.001
      Medicare / Medicaid55.855.755.8
      Private including HMO35.037.135.1
      Self pay/no charge/other9.06.98.9
      Hospital characteristics
      Hospital bed size<0.001
      Small6.96.96.9
      Medium18.822.119.0
      Large73.370.673.2
      Hospital Location
      Rural6.65.66.5
      Urban92.494.092.5
      Hospital Region<0.001
      Northeast20.319.520.3
      Midwest or North Central28.022.627.7
      South41.535.841.2
      West9.921.910.6
      Hospital Teaching status<0.001
      Non-teaching43.942.443.8
      Teaching55.157.155.2
      Admission types<0.001
      Emergent/Urgent74.569.074.2
      Elective admission24.629.924.9
      Admission day<0.001
      Weekdays83.387.183.5
      Weekend16.712.916.5
      No. of Vessel stents
      All the procedure and diagnosis were identified by using International Classification of Disease (ICD-9) codes. 36.06 Insertion of non-drug-eluting coronary artery stent (bare metal stent), 36.07 insertion of drug-eluting coronary artery stent, 410.xx acute myocardial infarction, 785.5x shock,00.40 procedure on single vessel, 00.41 procedure on two vessels, 00.42 procedure on three vessels, 00.43 procedure on four or more vessels, 00.44 procedure on vessel bifurcation, 00.45 insertion of one vascular stent, 00.46 insertion of two vascular stents, 00.47 insertion of three vascular stents, 00.48 insertion of four or more vascular stents.
      <0.001
      Single Vessel Single Stent50.350.750.3
      Single Vessel multiple stents17.222.317.5
      Bifurcation Stenting2.53.62.6
      Multivessel Stenting15.820.516.1
      Type of Stent
      All the procedure and diagnosis were identified by using International Classification of Disease (ICD-9) codes. 36.06 Insertion of non-drug-eluting coronary artery stent (bare metal stent), 36.07 insertion of drug-eluting coronary artery stent, 410.xx acute myocardial infarction, 785.5x shock,00.40 procedure on single vessel, 00.41 procedure on two vessels, 00.42 procedure on three vessels, 00.43 procedure on four or more vessels, 00.44 procedure on vessel bifurcation, 00.45 insertion of one vascular stent, 00.46 insertion of two vascular stents, 00.47 insertion of three vascular stents, 00.48 insertion of four or more vascular stents.
      Bare Metal Stent29.222.728.8<0.001
      Drug Eluting Stent73.179.973.5<0.001
      AMI46.333.045.5<0.001
      Shock1.41.01.3<0.001
      Length of stay (days) (Mean±SE)2.8±0.012.55±0.022.78±0.01<0.001
      Cost of Hospitalization($)(Means ± SE)18,019±1819,779±1418,111±18<0.001
      Disposition<0.001
      Home95.296.995.3
      Facility/others3.62.43.6
      Death0.80.40.8<0.001
      Race was missing in 18% of the study population and hence excluded in the multivariable analysis.
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      Variables are AHRQ comorbidity measures.
      § This represents a quartile classification of the estimated median household income of residents in the patient's ZIP Code. These values are derived from ZIP Code-demographic data obtained from Claritas. The quartiles are identified by values of 1 to 4, indicating the poorest to wealthiest populations. Because these estimates are updated annually, the value ranges vary by year. http://www.hcupus.ahrq.gov/db/vars/zipinc_qrtl/nisnote.jsp.
      All the procedure and diagnosis were identified by using International Classification of Disease (ICD-9) codes. 36.06 Insertion of non-drug-eluting coronary artery stent (bare metal stent), 36.07 insertion of drug-eluting coronary artery stent, 410.xx acute myocardial infarction, 785.5x shock,00.40 procedure on single vessel, 00.41 procedure on two vessels, 00.42 procedure on three vessels, 00.43 procedure on four or more vessels, 00.44 procedure on vessel bifurcation, 00.45 insertion of one vascular stent, 00.46 insertion of two vascular stents, 00.47 insertion of three vascular stents, 00.48 insertion of four or more vascular stents.
      The mean LOS for the population was 2.78 ± 0.01 days (2.5 ± 0.02 days for IVUS and 2.80 ± 0.01 days for AO PCIs, p <0.001). Overall cost of hospitalization was $18,111 ± 18 ($19,779 ± 14 for IVUS and $18,019 ± 18 for AO, p <0.001). The mortality rate was lower in patients receiving IVUS (0.4% in IVUS group vs 0.8% in angiography group, p <0.001). The overall complications rate was similar in the 2 groups (5.5%); however, vascular and iatrogenic cardiac complications were more frequent in the IVUS group (2% vs 1.7%, p <0.001, and 1.7% vs 1.4%, p <0.001; Table 2).
      Table 2Complications
      Details in supplementary Table 2.
      ComplicationsAngiography guided PCIIVUS guided PCIOverallP-value
      Overall any complication5.55.55.50.538
      Vascular complications1.721.8<0.001
      Postoperative hemorrhage requiring transfusion0.50.70.5<0.001
      Vascular injury1.21.41.3<0.001
      Cardiac complications1.41.81.5<0.001
      Iatrogenic cardiac complications1.41.71.4<0.001
      Pericardial complications0.10.10.1<0.001
      Requiring CABG0.010.010.010.012
      Respiratory complications (Post-op resp failure)1.511.5<0.001
      Postop-Stroke/TIA/Stroke effects0.20.20.20.372
      Renal and metabolic complications0.240.150.2<0.001
      Postoperative DVT/PE0.30.30.30.930
      Postop infectious complications0.50.40.50.01
      CABG = coronary artery bypass graft surgery; DVT = deep venous thrombosis; TIA = transient ischemic attack; PE = pulmonary embolism.
      Details in supplementary Table 2.
      In a multivariate model, significant predictors of higher mortality were increasing age, female gender, higher baseline co-morbidity burden (high CCI score), presence of AMI or shock, weekend and emergent admission, or occurrence of any complication during hospitalization (Table 3). Significant predictors of reduced mortality were use of IVUS guidance for PCI (odds ratio [OR] 0.65, 95% CI 0.52 to 0.83; p <0.001; Figure 1) and higher hospital volumes (third and fourth quartiles; Figure 2). Similar results were obtained in a multivariate analysis performed in a subgroup of patients with AMI and/or shock and those with higher co-morbidity burden (CCI score ≥2; Table 4 and Figures 1 and 2. Multivariate predictors of increased LOS and cost of hospitalization are listed in Table 5. The use of IVUS did not significantly alter the LOS; however, it was associated with slightly higher hospitalization costs compared with AO PCIs ($2302; 95% CI $1912 to $2693; p <0.001).
      Table 3Multivariate predictors of In-hospital Mortality
      VariablesOdds RatioLLULP-value
      Presence of any complications5.805.256.41<0.001
      Age (10 year increment)1.631.561.71<0.001
      Female1.121.031.220.007
      AMI3.703.244.23<0.001
      Shock15.4013.8617.12<0.001
      Charlson/Deyo comorbidity index
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
       0ReferentReferentReferent
       11.811.362.42<0.001
       ≥22.812.113.75<.001
      Median household income category for patient's zip code
      Please refer Table 1.
       1. 0-25th percentileReferentReferentReferent
       2. 26-50th percentile1.000.891.120.968
       3. 51-75th percentile0.970.861.100.620
       4. 76-100th percentile0.940.821.090.418
      Procedure
       AngiographyReferentReferentReferent
       IVUS0.650.520.83<0.001
      Primary Payer
       Medicare / MedicaidReferentReferentReferent
       Private including HMO0.860.750.970.018
       Self pay/no charge/other1.271.071.510.007
       Teaching vs non-teaching hospital1.020.911.140.717
       Weekend vs Weekdays admission1.141.041.260.007
       Emergent/urgent admission vs elective1.581.361.84<.001
      Hospital Region
       NortheastReferentReferentReferent
       Midwest or North Central1.170.981.390.083
       South1.451.231.71<.001
       West1.170.961.430.128
      hospital Volume (Quartile)
       1st Quartile (1-313)ReferentReferentReferent
       2nd Quartile (314- 539)1.000.881.130.937
       3rd Quartile (540 - 947)0.860.750.990.039
       4th Quartile ( 948- 3420)0.750.630.900.002
       c-Index0.92
      HMO = Health Maintenance Organization.
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      Please refer Table 1.
      Figure thumbnail gr1
      Figure 1Effect of IVUS on inhospital mortality.
      Figure thumbnail gr2
      Figure 2Effect of hospital volume on inhospital mortality.
      Table 4Multivariate analysis in-hospital mortality in different subgroups
      VariablesAMI and/or ShockCharlson Score >= 2
      Odds ratioLLULP-valueOdds ratioLLULP-value
      Presence of any complications9.008.229.84<.0014.904.375.48<.001
      Age (10 year increment)1.611.541.69<.0011.601.521.68<.001
      Female1.121.031.210.0061.050.951.150.347
      AMIReferent Group3.402.933.94<.001
      Shock13.0111.5514.67<.001
      Charlson/Deyo comorbidity index
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
       0Referent Group
       1ReferentReferentReferent
       ≥21.661.511.83<.001
      Median household income category for patient's zip code
       1. 0-25th percentileReferentReferentReferentReferentReferentReferent
       2. 26-50th percentile1.030.931.150.5590.980.861.110.713
       3. 51-75th percentile0.960.861.090.5391.010.871.160.934
       4. 76-100th percentile1.010.871.160.9250.990.861.150.932
      Procedure
       AngiographyReferentReferentReferentReferentReferentReferent
       IVUS0.640.510.80<.0010.640.480.840.002
      Primary Payer
       Medicare / MedicaidReferentReferentReferentReferentReferentReferent
       Private including HMO0.820.720.930.0020.870.751.010.075
       Self pay/no charge/other1.281.081.510.0041.150.941.410.174
       Teaching vs non-teaching hospital0.980.881.100.7471.010.891.140.920
       Weekend vs Weekdays admission1.161.061.270.0011.131.011.260.029
       Emergent/urgent admission vs elective1.591.351.88<.0011.591.331.92<.001
      Hospital Region
       NortheastReferentReferentReferentReferentReferentReferent
       Midwest or North Central1.201.011.430.0371.180.991.400.067
       South1.391.171.65<.0011.431.211.69<.001
       West1.221.001.490.0491.140.921.400.231
      hospital Volume (Quartile)
       1st Quartile (1-313)ReferentReferentReferentReferentReferentReferent
       2nd Quartile (314- 539)0.970.861.100.6361.010.881.160.882
       3rd Quartile (540 - 947)0.860.750.990.0410.870.741.010.063
       4th Quartile ( 948- 3420)0.760.640.900.0010.720.590.870.001
       c-Index0.830.89
      HMO = Health Maintenance Organization.
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      Table 5Multivariate predictors of length of hospital stay and cost of Hospitalization
      VariablesLength of stayCost of Hospitalization
      DaysLLULP-valueUSD ($)LLULP-value
      Presence of any complications2.652.532.76<.001754473077781<.001
      Age (10 year increment)0.180.170.20<.001186146226<.001
      Female0.240.220.26<.001-29-87290.331
      AMI0.500.440.56<.001180016161983<.001
      Shock3.893.654.13<.001107571014111372<.001
      Charlson/ Deyocomorbity index
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
       0ReferentReferentReferentReferentReferentReferent
       10.190.150.22<.001463369558<.001
       ≥ 21.111.041.17<.001223120402422<.001
      Median household income category for patient's zip code
      Please refer Table 1.
       1. 0-25th percentileReferentReferentReferentReferentReferentReferent
       2. 26-50th percentile-0.10-0.15-0.06<.001-4-1681600.964
       3. 51-75th percentile-0.10-0.16-0.05<.001-257-451-630.010
       4. 76-100th percentile-0.15-0.23-0.07<.001-99-5573600.673
      Procedure
       AngiographyReferentReferentReferentReferentReferentReferent
       IVUS-0.01-0.080.050.687230219122693<.001
      Primary Payer
       Medicare / MedicaidReferentReferentReferentReferentReferentReferent
       Private including HMO-0.19-0.21-0.16<.001-97-20280.072
       Self pay/no charge/other-0.07-0.12-0.020.005-587-808-366<.001
       Teaching vs non-teaching hospital0.01-0.100.120.867374-2339800.228
       Weekend vs Weekdays admission0.510.470.55<.001127311591386<.001
       Emergent/urgent admission vs elective0.940.861.01<.001201016762345<.001
      Hospital Region
       NortheastReferentReferentReferentReferentReferentReferent
       Midwest or North Central-0.21-0.37-0.050.009-290-181012290.708
       South-0.01-0.180.170.947-1103-24722660.115
       West-0.32-0.50-0.150.000816-60922400.262
      hospital Volume (Quartile)
       1st Quartile (1-313)ReferentReferentReferentReferentReferentReferent
       2nd Quartile (314- 539)-0.09-0.17-0.020.014-1994-2669-1319<.001
       3rd Quartile (540 - 947)-0.23-0.34-0.12<.001-2557-3272-1841<.001
       4th Quartile ( 948- 3420)-0.43-0.56-0.30<.001-3309-4152-2467<.001
      AMI = acute myocardial infarction, HMO = Health Maintenance Organization, IVUS = intravascular ultrasound.
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      Please refer Table 1.
      Propensity score match analysis is listed in Table 6. In this analysis, multiple patient- and hospital-level variables that could have affected treatment selection were adjusted for. These variables included age, gender, AMI, shock, CCI, median household income, primary payer, admission day, admission type, hospital teaching status, hospital region, and hospital volume. The propensity score matching analysis also showed a reduction in inhospital mortality, increase in cost of hospitalization, and no change with LOS associated with using IVUS.
      Table 6Propensity score match cohort
      Angiography guided PCIIVUS guided PCIP-value
      Overall23,46523,465
      Age(years)64.4±0.0764.2±0.070.043
      Female34.6235.380.082
      AMI31.932.80.046
      Shock0.60.92<.001
      Charlson/Deyo comorbidity index
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      0.209
       024.625.3
       138.037.6
       >=237.437.2
      Median household income category for patient's zip code
      Please refer Table 1.
      0.280
       1. 0-25th percentile24.224.9
       2. 26-50th percentile25.825.8
       3. 51-75th percentile24.924.8
       4. 76-100th percentile25.124.6
      Primary Payer0.053
       Medicare / Medicaid56.855.7
       Private including HMO36.537.3
       Self pay/no charge/other6.76.9
      Hospital Teaching status0.556
       Non-teaching42.242.5
       Teaching57.857.6
      Admission day<0.001
       Weekdays88.387.2
       Weekend11.712.8
      Admission types0.146
       Emergent/Urgent70.670.0
       Elective admission29.430.0
      Hospital Region<.001
       Northeast19.819.6
       Midwest or North Central22.822.6
       South38.536.7
       West18.921.1
      Hospital Volume (Quartile)0.046
       1st Quartile (1-313)23.423.9
       2nd Quartile (314- 539)24.925.3
       3rd Quartile (540 - 947)21.120.1
       4th Quartile ( 948- 3420)30.630.6
      Outcomes
       Death0.550.40.019
       Length of stay(days)2.5± 0.012.54± 0.010.213
       Cost of Hospitalization($)17,208± 6419,702± 72<.001
      Charlson/Deyo comorbidity index was calculated as per Deyo classification.
      Please refer Table 1.

      Discussion

      In one of the largest studies on IVUS-guided PCIs in the DES era, we demonstrate that IVUS-guided PCI is associated with reduced inhospital mortality, no effect on the LOS, and minimal increase in the cost of care compared with conventional angiography-guided PCIs. Overall complication's rate (identified by PSIs) was similar in the 2 groups, however, the use of IVUS was associated with a higher rate of vascular and cardiac complications.
      The use of IVUS (class IIa recommendation as per the American College of Cardiology/American Hospital Association PCI guidelines for use in angiographically intermediate coronary stenosis) has been previously associated with improved procedural and clinical outcomes.
      • Parise H.
      • Maehara A.
      • Stone G.W.
      • Leon M.B.
      • Mintz G.S.
      Meta-analysis of randomized studies comparing intravascular ultrasound versus angiographic guidance of percutaneous coronary intervention in pre-drug-eluting stent era.
      • Tonino P.A.
      • De Bruyne B.
      • Pijls N.H.
      • Siebert U.
      • Ikeno F.
      • van' t Veer M.
      • Klauss V.
      • Manoharan G.
      • Engstrom T.
      • Oldroyd K.G.
      • Ver Lee P.N.
      • MacCarthy P.A.
      • Fearon W.F.
      Fractional flow reserve versus angiography for guiding percutaneous coronary intervention.
      • Levine G.N.
      • Bates E.R.
      • Blankenship J.C.
      • Bailey S.R.
      • Bittl J.A.
      • Cercek B.
      • Chambers C.E.
      • Ellis S.G.
      • Guyton R.A.
      • Hollenberg S.M.
      • Khot U.N.
      • Lange R.A.
      • Mauri L.
      • Mehran R.
      • Moussa I.D.
      • Mukherjee D.
      • Nallamothu B.K.
      • Ting H.H.
      2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice guidelines and the Society for Cardiovascular Angiography and Interventions.
      Published studies have noted IVUS to reduce restenosis and repeat revascularization rates after BMS implantation without any significant impact on post-PCI MI or mortality.
      • Parise H.
      • Maehara A.
      • Stone G.W.
      • Leon M.B.
      • Mintz G.S.
      Meta-analysis of randomized studies comparing intravascular ultrasound versus angiographic guidance of percutaneous coronary intervention in pre-drug-eluting stent era.
      Although the restenosis rates have dramatically improved since introduction of DES, stent thrombosis remains a serious concern. Most stent thrombosis occurs in the first 30 days after stent implantation mostly because of technical and procedural factors. Although IVUS-guided PCI has not been shown to affect restenosis rates in DES, it has been posited to reduce stent thrombosis rates, thus, positively influencing mortality outcomes after DES implantation.
      The Angiography versus IVUS Optimization study failed to show any significant effect of IVUS-guided PCI on stent thrombosis or mortality outcomes.
      • Chieffo A.
      • Latib A.
      • Caussin C.
      • Presbitero P.
      • Galli S.
      • Menozzi A.
      • Varbella F.
      • Mauri F.
      • Valgimigli M.
      • Arampatzis C.
      • Sabate M.
      • Erglis A.
      • Reimers B.
      • Airoldi F.
      • Laine M.
      • Palop R.L.
      • Mikhail G.
      • Maccarthy P.
      • Romeo F.
      • Colombo A.
      A prospective, randomized trial of intravascular-ultrasound guided compared to angiography guided stent implantation in complex coronary lesions: the AVIO trial.
      A recently published cohort study based on the pan-London (United Kingdom) PCI registry also did not show any significant difference in inhospital mortality between the IVUS-guided PCI group (13 of 1,831 patients [0.7%]) and the angiography-guided PCI group (177 of 37,090 patients [0.5%]; p = 0.12).
      • Frohlich G.M.
      • Redwood S.
      • Rakhit R.
      • MacCarthy P.A.
      • Lim P.
      • Crake T.
      • White S.K.
      • Knight C.J.
      • Kustosz C.
      • Knapp G.
      • Dalby M.C.
      • Mali I.S.
      • Archbold A.
      • Wragg A.
      • Timmis A.D.
      • Meier P.
      Long-term survival in patients undergoing percutaneous interventions with or without intracoronary pressure wire guidance or intracoronary ultrasonographic imaging: a large cohort study.
      In the current era of improved PCI outcomes and consequential rarity of stent thrombosis and inhospital deaths, these studies were possibly underpowered to detect significant difference in mortality. This hypothesis is supported by a recent (largest till date) randomized trial: The Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents and another meta-analysis (which included this trial), which suggest that IVUS guidance may reduce stent thrombosis and cardiac mortality in the DES era in contradiction to the earlier smaller studies.
      • Zhang Y.
      • Farooq V.
      • Garcia-Garcia H.M.
      • Bourantas C.V.
      • Tian N.
      • Dong S.
      • Li M.
      • Yang S.
      • Serruys P.W.
      • Chen S.L.
      Comparison of intravascular ultrasound versus angiography-guided drug-eluting stent implantation: a meta-analysis of one randomised trial and ten observational studies involving 19,619 patients.
      • Witzenbichler B.
      • Maehara A.
      • Weisz G.
      • Neumann F.J.
      • Rinaldi M.J.
      • Metzger D.C.
      • Henry T.D.
      • Cox D.A.
      • Duffy P.L.
      • Brodie B.R.
      • Stuckey T.D.
      • Mazzaferri Jr., E.L.
      • Xu K.
      • Parise H.
      • Mehran R.
      • Mintz G.S.
      • Stone G.W.
      Relationship between intravascular ultrasound guidance and clinical outcomes after drug-eluting stents: the assessment of dual antiplatelet therapy with drug-eluting stents (ADAPT-DES) study.
      • Ahn J.M.
      • Kang S.J.
      • Yoon S.H.
      • Park H.W.
      • Kang S.M.
      • Lee J.Y.
      • Lee S.W.
      • Kim Y.H.
      • Lee C.W.
      • Park S.W.
      • Mintz G.S.
      • Park S.J.
      Meta-analysis of outcomes after intravascular ultrasound-guided versus angiography-guided drug-eluting stent implantation in 26,503 patients enrolled in three randomized trials and 14 observational studies.
      • Ahmed K.
      • Jeong M.H.
      • Chakraborty R.
      • Ahn Y.
      • Sim D.S.
      • Park K.
      • Hong Y.J.
      • Kim J.H.
      • Cho K.H.
      • Kim M.C.
      • Hachinohe D.
      • Hwang S.H.
      • Lee M.G.
      • Cho M.C.
      • Kim C.J.
      • Kim Y.J.
      • Park J.C.
      • Kang J.C.
      Role of intravascular ultrasound in patients with acute myocardial infarction undergoing percutaneous coronary intervention.
      • Maluenda G.
      • Lemesle G.
      • Ben-Dor I.
      • Collins S.D.
      • Syed A.I.
      • Torguson R.
      • Kaneshige K.
      • Xue Z.
      • Suddath W.O.
      • Satler L.F.
      • Kent K.M.
      • Lindsay J.
      • Pichard A.D.
      • Waksman R.
      Impact of intravascular ultrasound guidance in patients with acute myocardial infarction undergoing percutaneous coronary intervention.
      Most of these differences were because of reduction in stent thrombosis and periprocedural MIs, which may occur during the same hospitalization.
      • Ahn J.M.
      • Kang S.J.
      • Yoon S.H.
      • Park H.W.
      • Kang S.M.
      • Lee J.Y.
      • Lee S.W.
      • Kim Y.H.
      • Lee C.W.
      • Park S.W.
      • Mintz G.S.
      • Park S.J.
      Meta-analysis of outcomes after intravascular ultrasound-guided versus angiography-guided drug-eluting stent implantation in 26,503 patients enrolled in three randomized trials and 14 observational studies.
      Besides defining accurate coronary anatomy, IVUS further affords the additional utility of appropriate stent sizing and postimplantation stent optimization in terms of expansion and apposition. Thus, superior outcomes with IVUS-guided PCI might conceptually be in part a result of earlier recognition of periprocedural complications like stent fracture, malapposition, or underexpansion. The acute (inpatient or <30 days) benefits of IVUS-guided PCIs have also been reported from the CathPCI Registry and the MATRIX registry.
      • Dattilo P.B.
      • Prasad A.
      • Honeycutt E.
      • Wang T.Y.
      • Messenger J.C.
      Contemporary patterns of fractional flow reserve and intravascular ultrasound use among patients undergoing percutaneous coronary intervention in the United States: insights from the National Cardiovascular Data Registry.
      • Claessen B.E.
      • Mehran R.
      • Mintz G.S.
      • Weisz G.
      • Leon M.B.
      • Dogan O.
      • de Ribamar Costa Jr., J.
      • Stone G.W.
      • Apostolidou I.
      • Morales A.
      • Chantziara V.
      • Syros G.
      • Sanidas E.
      • Xu K.
      • Tijssen J.G.
      • Henriques J.P.
      • Piek J.J.
      • Moses J.W.
      • Maehara A.
      • Dangas G.D.
      Impact of intravascular ultrasound imaging on early and late clinical outcomes following percutaneous coronary intervention with drug-eluting stents.
      Similar to our study, the CathPCI registry demonstrated the use of IVUS to be associated with higher rates of major bleeding (OR 1.23; interquartile range 1.09 to 1.38; p <0.001) but lower rates of inhospital death (OR 0.66; interquartile range 0.44 to 0.98; p = 0.04).
      • Dattilo P.B.
      • Prasad A.
      • Honeycutt E.
      • Wang T.Y.
      • Messenger J.C.
      Contemporary patterns of fractional flow reserve and intravascular ultrasound use among patients undergoing percutaneous coronary intervention in the United States: insights from the National Cardiovascular Data Registry.
      The use of IVUS was associated with a higher rate of cardiac complications compared with AO PCIs in our study; this could be because of poor interpretation of IVUS data that occasionally results in overdilation of stents, perforations, and cardiac tamponade. Similarly, the MATRIX registry (patients treated with sirolimus-eluting stents) showed that IVUS group had significantly less death/MI at 30 days compared with AO (1.5% vs 4.6%, p <0.01).
      • Claessen B.E.
      • Mehran R.
      • Mintz G.S.
      • Weisz G.
      • Leon M.B.
      • Dogan O.
      • de Ribamar Costa Jr., J.
      • Stone G.W.
      • Apostolidou I.
      • Morales A.
      • Chantziara V.
      • Syros G.
      • Sanidas E.
      • Xu K.
      • Tijssen J.G.
      • Henriques J.P.
      • Piek J.J.
      • Moses J.W.
      • Maehara A.
      • Dangas G.D.
      Impact of intravascular ultrasound imaging on early and late clinical outcomes following percutaneous coronary intervention with drug-eluting stents.
      Our study represents the largest comparative analysis between IVUS- and angiography-guided PCI in the current DES era, which adds to the growing literature on beneficial effects of IVUS on reducing adverse outcomes after PCI.
      Our study is also unique in including all-comers real-world data from patients admitted with AMI and cardiogenic shock. A subgroup analysis of these higher risk populations showed similar results with IVUS-guided PCI independently predicting superior mortality outcomes after PCI. This is in contrast to a few previously published studies like the Korea Acute Myocardial Infarction Registry that did not support the routine use of IVUS during PCI in the setting of AMI.
      • Ahmed K.
      • Jeong M.H.
      • Chakraborty R.
      • Ahn Y.
      • Sim D.S.
      • Park K.
      • Hong Y.J.
      • Kim J.H.
      • Cho K.H.
      • Kim M.C.
      • Hachinohe D.
      • Hwang S.H.
      • Lee M.G.
      • Cho M.C.
      • Kim C.J.
      • Kim Y.J.
      • Park J.C.
      • Kang J.C.
      Role of intravascular ultrasound in patients with acute myocardial infarction undergoing percutaneous coronary intervention.
      The utility of IVUS guidance has been debated in the past because of minimal clinical benefit observed in the previous small studies and because of significant reduction in restenosis rates after the introduction of DES into clinical practice. This issue is further complicated because of financial reasons, higher costs of catheters, and low reimbursement. Our analysis, thus, suggests a very low rate of utilization of IVUS (6%) compared with AO (93.5% of the cases). The higher cost and time required for this procedure may, however, be offset by a reduction in mortality as seen in larger studies such as ours. Newer and improved technologies such as Optical Coherence Tomography and Infrared techniques may also contribute to possible similar improved outcomes.
      The study limitations are inherent to the post hoc analysis of an administrative database. The design of our study further restricts any inference of causality or temporal associations. Compared with previous studies, we lack information on coronary anatomy, lesion characteristics, and stent sizes. Likewise, we lack data on procedural details (IVUS utilization preintervention vs postintervention or both) that could shed more light on the mechanism of observed benefits in our study. In addition, we did not have postdischarge data on mortality as the NIS does not track individual patients over time. However, the impact of IVUS-guided PCIs on these individual characteristics with longer follow-ups has been previously demonstrated in several studies. We aimed to analyze a larger unrestricted population to appraise rare events associated with PCIs, such as inhospital mortality, which were not well captured by previous smaller studies. Although acknowledging these limitations, the present study has important strengths including the largest sample size and the use of standardized definitions of preventable adverse events that are established by the AHRQ. Our results need to be replicated in larger randomized trials with detailed angiographic analysis to better understand the pathophysiological underpinnings of positive outcomes afforded by IVUS guidance.

      Disclosures

      None of the other authors have any disclosures relevant to the content of the manuscript.

      References

        • Casella G.
        • Klauss V.
        • Ottani F.
        • Siebert U.
        • Sangiorgio P.
        • Bracchetti D.
        Impact of intravascular ultrasound-guided stenting on long-term clinical outcome: a meta-analysis of available studies comparing intravascular ultrasound-guided and angiographically guided stenting.
        Catheter Cardiovasc Interv. 2003; 59: 314-321
        • Parise H.
        • Maehara A.
        • Stone G.W.
        • Leon M.B.
        • Mintz G.S.
        Meta-analysis of randomized studies comparing intravascular ultrasound versus angiographic guidance of percutaneous coronary intervention in pre-drug-eluting stent era.
        Am J Cardiol. 2011; 107: 374-382
        • Jakabcin J.
        • Spacek R.
        • Bystron M.
        • Kvasnak M.
        • Jager J.
        • Veselka J.
        • Kala P.
        • Cervinka P.
        Long-term health outcome and mortality evaluation after invasive coronary treatment using drug eluting stents with or without the IVUS guidance. Randomized control trial. HOME DES IVUS.
        Catheter Cardiovasc Interv. 2010; 75: 578-583
        • Chieffo A.
        • Latib A.
        • Caussin C.
        • Presbitero P.
        • Galli S.
        • Menozzi A.
        • Varbella F.
        • Mauri F.
        • Valgimigli M.
        • Arampatzis C.
        • Sabate M.
        • Erglis A.
        • Reimers B.
        • Airoldi F.
        • Laine M.
        • Palop R.L.
        • Mikhail G.
        • Maccarthy P.
        • Romeo F.
        • Colombo A.
        A prospective, randomized trial of intravascular-ultrasound guided compared to angiography guided stent implantation in complex coronary lesions: the AVIO trial.
        Am Heart J. 2013; 165: 65-72
        • Zhang Y.
        • Farooq V.
        • Garcia-Garcia H.M.
        • Bourantas C.V.
        • Tian N.
        • Dong S.
        • Li M.
        • Yang S.
        • Serruys P.W.
        • Chen S.L.
        Comparison of intravascular ultrasound versus angiography-guided drug-eluting stent implantation: a meta-analysis of one randomised trial and ten observational studies involving 19,619 patients.
        EuroIntervention. 2012; 8: 855-865
        • Witzenbichler B.
        • Maehara A.
        • Weisz G.
        • Neumann F.J.
        • Rinaldi M.J.
        • Metzger D.C.
        • Henry T.D.
        • Cox D.A.
        • Duffy P.L.
        • Brodie B.R.
        • Stuckey T.D.
        • Mazzaferri Jr., E.L.
        • Xu K.
        • Parise H.
        • Mehran R.
        • Mintz G.S.
        • Stone G.W.
        Relationship between intravascular ultrasound guidance and clinical outcomes after drug-eluting stents: the assessment of dual antiplatelet therapy with drug-eluting stents (ADAPT-DES) study.
        Circulation. 2014; 129: 463-470
        • Ahn J.M.
        • Kang S.J.
        • Yoon S.H.
        • Park H.W.
        • Kang S.M.
        • Lee J.Y.
        • Lee S.W.
        • Kim Y.H.
        • Lee C.W.
        • Park S.W.
        • Mintz G.S.
        • Park S.J.
        Meta-analysis of outcomes after intravascular ultrasound-guided versus angiography-guided drug-eluting stent implantation in 26,503 patients enrolled in three randomized trials and 14 observational studies.
        Am J Cardiol. 2014; 113: 1338-1347
        • Dattilo P.B.
        • Prasad A.
        • Honeycutt E.
        • Wang T.Y.
        • Messenger J.C.
        Contemporary patterns of fractional flow reserve and intravascular ultrasound use among patients undergoing percutaneous coronary intervention in the United States: insights from the National Cardiovascular Data Registry.
        J Am Coll Cardiol. 2012; 60: 2337-2339
        • Kumar G.
        • Kumar N.
        • Taneja A.
        • Kaleekal T.
        • Tarima S.
        • McGinley E.
        • Jimenez E.
        • Mohan A.
        • Khan R.A.
        • Whittle J.
        • Jacobs E.
        • Nanchal R.
        Nationwide trends of severe sepsis in the 21st century (2000-2007).
        Chest. 2011; 140: 1223-1231
        • Deshmukh A.
        • Kumar G.
        • Kumar N.
        • Nanchal R.
        • Gobal F.
        • Sakhuja A.
        • Mehta J.L.
        Effect of Joint National Committee VII report on hospitalizations for hypertensive emergencies in the United States.
        Am J Cardiol. 2011; 108: 1277-1282
        • Deshmukh A.
        • Patel N.J.
        • Pant S.
        • Shah N.
        • Chothani A.
        • Mehta K.
        • Grover P.
        • Singh V.
        • Vallurupalli S.
        • Savani G.T.
        • Badheka A.
        • Tuliani T.
        • Dabhadkar K.
        • Dibu G.
        • Reddy Y.M.
        • Sewani A.
        • Kowalski M.
        • Mitrani R.
        • Paydak H.
        • Viles-Gonzalez J.F.
        In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.
        Circulation. 2013; 128: 2104-2112
        • Patel N.J.
        • Deshmukh A.
        • Pant S.
        • Singh V.
        • Patel N.
        • Arora S.
        • Shah N.
        • Chothani A.
        • Savani G.T.
        • Mehta K.
        • Parikh V.
        • Rathod A.
        • Badheka A.O.
        • Lafferty J.
        • Kowalski M.
        • Mehta J.L.
        • Mitrani R.D.
        • Viles-Gonzalez J.F.
        • Paydak H.
        Trends of hospitalization for atrial fibrillation in the United States, 2000 through 2010: implications for healthcare planning.
        Circulation. 2014; 129: 2371-2379
        • Badheka A.O.
        • Patel N.J.
        • Singh V.
        • Shah N.
        • Chothani A.
        • Mehta K.
        • Deshmukh A.
        • Ghatak A.
        • Rathod A.
        • Desai H.
        • Savani G.T.
        • Grover P.
        • Patel N.
        • Arora S.
        • Grines C.L.
        • Schreiber T.
        • Makkar R.
        • Rihal C.S.
        • Cohen M.G.
        • De Marchena E.
        • O'Neill W.W.
        Percutaneous aortic balloon valvotomy in the US: a 13 years perspective.
        Am J Med. 2014; 127: 744-753.e3
        • Badheka A.O.
        • Shah N.
        • Ghatak A.
        • Patel N.J.
        • Chothani A.
        • Mehta K.
        • Patel N.
        • Singh V.
        • Grover P.
        • Deshmukh A.
        • Panaich S.S.
        • Savani G.T.
        • Bhalara V.
        • Arora S.
        • Rathod A.
        • Desai H.
        • Kar S.
        • Alfonso C.
        • Palacios I.F.
        • Grines C.
        • Schreiber T.
        • Rihal C.S.
        • Makkar R.
        • Cohen M.G.
        • O'Neill W.
        • de Marchena E.
        Balloon mitral valvuloplasty in United States: a 13 year perspective.
        Am J Med. 2014; 127: 1126.e1-1126.e12
        • Zipes D.P.
        • Wellens H.J.
        Sudden cardiac death.
        Circulation. 1998; 98: 2334-2351
        • McDonald K.M.
        • Romano P.S.
        • Geppert J.
        • Davies S.M.
        • Duncan B.W.
        • Shojania K.G.
        • Hansen A.
        Measures of Patient Safety Based on Hospital Administrative Data—The Patient Safety Indicators.
        Agency for Healthcare Reseach and Quality, Rockville2002 (Structured Abstract, vol 02-0038)
        • Romano P.S.
        • Geppert J.J.
        • Davies S.
        • Miller M.R.
        • Elixhauser A.
        • McDonald K.M.
        A national profile of patient safety in U.S. hospitals.
        Health Aff (Millwood). 2003; 22: 154-166
        • Jan S.L.
        • Shieh G.
        Sample size determinations for Welch's test in one-way heteroscedastic ANOVA.
        Br J Math Psychol. 2013; 67: 72-93
        • Greenland S.
        Dose-response and trend analysis in epidemiology: alternatives to categorical analysis.
        Epidemiology. 1995; 6: 356-365
        • Badheka A.O.
        • Arora S.
        • Panaich S.S.
        • Patel N.J.
        • Patel N.
        • Chothani A.
        • Mehta K.
        • Deshmukh A.
        • Singh V.
        • Savani G.T.
        • Agnihotri K.
        • Grover P.
        • Lahewala S.
        • Patel A.
        • Bambhroliya C.
        • Kondur A.
        • Brown M.
        • Elder M.
        • Kaki A.
        • Mohammad T.
        • Grines C.
        • Schreiber T.
        Impact on in-hospital outcomes with drug-eluting stents versus bare-metal stents (from 665,804 procedures).
        Am J Cardiol. 2014; 114: 1629-1637
        • Tonino P.A.
        • De Bruyne B.
        • Pijls N.H.
        • Siebert U.
        • Ikeno F.
        • van' t Veer M.
        • Klauss V.
        • Manoharan G.
        • Engstrom T.
        • Oldroyd K.G.
        • Ver Lee P.N.
        • MacCarthy P.A.
        • Fearon W.F.
        Fractional flow reserve versus angiography for guiding percutaneous coronary intervention.
        N Engl J Med. 2009; 360: 213-224
        • Levine G.N.
        • Bates E.R.
        • Blankenship J.C.
        • Bailey S.R.
        • Bittl J.A.
        • Cercek B.
        • Chambers C.E.
        • Ellis S.G.
        • Guyton R.A.
        • Hollenberg S.M.
        • Khot U.N.
        • Lange R.A.
        • Mauri L.
        • Mehran R.
        • Moussa I.D.
        • Mukherjee D.
        • Nallamothu B.K.
        • Ting H.H.
        2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice guidelines and the Society for Cardiovascular Angiography and Interventions.
        Circulation. 2011; 124: e574-e651
        • Frohlich G.M.
        • Redwood S.
        • Rakhit R.
        • MacCarthy P.A.
        • Lim P.
        • Crake T.
        • White S.K.
        • Knight C.J.
        • Kustosz C.
        • Knapp G.
        • Dalby M.C.
        • Mali I.S.
        • Archbold A.
        • Wragg A.
        • Timmis A.D.
        • Meier P.
        Long-term survival in patients undergoing percutaneous interventions with or without intracoronary pressure wire guidance or intracoronary ultrasonographic imaging: a large cohort study.
        JAMA Intern Med. 2014; 174: 1360-1366
        • Ahmed K.
        • Jeong M.H.
        • Chakraborty R.
        • Ahn Y.
        • Sim D.S.
        • Park K.
        • Hong Y.J.
        • Kim J.H.
        • Cho K.H.
        • Kim M.C.
        • Hachinohe D.
        • Hwang S.H.
        • Lee M.G.
        • Cho M.C.
        • Kim C.J.
        • Kim Y.J.
        • Park J.C.
        • Kang J.C.
        Role of intravascular ultrasound in patients with acute myocardial infarction undergoing percutaneous coronary intervention.
        Am J Cardiol. 2011; 108: 8-14
        • Maluenda G.
        • Lemesle G.
        • Ben-Dor I.
        • Collins S.D.
        • Syed A.I.
        • Torguson R.
        • Kaneshige K.
        • Xue Z.
        • Suddath W.O.
        • Satler L.F.
        • Kent K.M.
        • Lindsay J.
        • Pichard A.D.
        • Waksman R.
        Impact of intravascular ultrasound guidance in patients with acute myocardial infarction undergoing percutaneous coronary intervention.
        Catheter Cardiovasc Interv. 2010; 75: 86-92
        • Claessen B.E.
        • Mehran R.
        • Mintz G.S.
        • Weisz G.
        • Leon M.B.
        • Dogan O.
        • de Ribamar Costa Jr., J.
        • Stone G.W.
        • Apostolidou I.
        • Morales A.
        • Chantziara V.
        • Syros G.
        • Sanidas E.
        • Xu K.
        • Tijssen J.G.
        • Henriques J.P.
        • Piek J.J.
        • Moses J.W.
        • Maehara A.
        • Dangas G.D.
        Impact of intravascular ultrasound imaging on early and late clinical outcomes following percutaneous coronary intervention with drug-eluting stents.
        JACC Cardiovas Intervent. 2011; 4: 974-981