Evolution of In-Hospital Outcomes Among Left Ventricular Assist Device Recipients

Continuous-flow left ventricular support devices (LVADs) are increasingly used for the management of patients with end-stage heart failure, both as a bridge to transplantation and as long-term permanent therapy, and their use for certain indications is supported by the most recent American College of Cardiology/American Heart Association guidelines (class of recommendation 1, level of evidence A). LVADs have been shown to prolong survival in this clinical setting, but there are several complications associated with these devices, despite advances in technology, patient selection, surgical techniques, and postoperative management. The postoperative course is complicated by frequent readmissions for bleeding, infection, pump thrombosis, right heart failure, and device malfunctions that require proper attention and management. Since 2017, two important events have had a significant impact on the utilization practices and outcomes of LVAD candidates: the approval of the HeartMate 3 LVAD, which is currently the only durable LVAD implanted in the United States, and the implementation of a six-tiered new donor heart allocation system after October 18, 2018. Although the long-term outcomes related to the utilization of newer devices are well studied, the evidence on short-term outcomes regarding these major changes in the field is limited. In this study, we sought to investigate the trends in in-hospital outcomes and readmissions of LVAD recipients based on data from a nationally representative sample of LVAD recipients. For this purpose, we queried the Nationwide Readmissions Database, which is the largest publicly available all-payer in-patient readmission database in the United States and includes all discharge records except those for long-term acute care facilities. National estimates (weighted) are available through a variable “discwt,” and the Nationwide Readmissions Database contains data of 35 million weighted discharges from 28 geographically dispersed states, accounting for approximately 60% of the total US population and hospitalizations. Because of this population-based retrospective nature of the study with de-identified patient records, institutional review board approval was not required. We conducted a retrospective analysis of adult recipients of LVAD from 2016 (the last year during which HeartMate II LVAD was the main device used) until 2019 (the year after the implementation of the new allocation system during which more than 3/4 of patients received the HeartMate 3 LVAD). The International Classification of Diseases, tenth revision procedure code “02HA0QZ” was used to identify patients who underwent LVAD implantation. From the database, patients who underwent heart transplant, biventricular assist device, temporary mechanical circulatory support, and percutaneous external heart assist device were excluded. We examined the main hospital outcomes per year of implantation and compared patient characteristics of those with and without readmissions. The baseline characteristics, co-morbidities, and complications during the index admission for LVAD implantation between patients with and without readmission were compared using Pearson chi-square test and independent t test for categorical and continuous variables, respectively. Categorical variables were reported as percentages, and continuous variables were reported as mean ± SD. Regarding trend analysis, hospitalizations and outcomes were reported as absolute values for each calendar year and compared using one-way analysis of variance. All data extraction and analyses were conducted using Stata 17.0 (StataCorp 2019; Stata Statistical Software: Release 17, College Station, Texas: StataCorp LLC, College Station, Texas). Two-sided p <0.05 was used for statistical significance.