The Case for Chronic Kidney Disease, Diabetes Mellitus, and Myocardial Infarction Being Equivalent Risk Factors for Cardiovascular Mortality in Patients Older Than 65 Years

The objective of the study was to determine whether chronic kidney disease (CKD) is as important a risk as either diabetes mellitus (DM) or previous myocardial infarction (MI). CKD and DM are important coronary artery disease risk factors. We hypothesized that the risk of cardiovascular mortality in elderly patients with CKD is equivalent to that for patients with either DM or previous MI. The CHS limited-access database was used to identify a cohort of patients with a baseline history of MI, DM, or CKD (estimated glomerular filtration rate <60 ml/min). Subjects were categorized in 1 of 3 groups as group 1, patients with DM (no CKD or MI); group 2, patients with previous MI (no DM or CKD); and group 3, patients with CKD (no DM or MI). Patients were followed up for a mean of 8.6 years, and rates of cardiovascular mortality were compared using proportional hazards regression. There were 789, 443, and 667 people in the MI, DM, and CKD groups, respectively. During follow-up, 124 patients (15.7%) died of cardiovascular causes in the MI group, and 69 (15.8%) and 87 (13%), in the DM and CKD groups, respectively. After adjusting for age, race, gender, smoking, hypertension, and total, high-density lipoprotein, and low-density lipoprotein cholesterol, the hazard ratio (HR) for cardiovascular mortality was similar between the DM (HR 1.0, 95% confidence interval 0.8 to 1.4)) and CKD cohorts (HR 0.8, 95% confidence interval 0.6 to 1.1) compared with the MI group. In conclusion, the risk of cardiovascular mortality in patients with moderate CKD was as high as that in patients with a history of MI or DM. Designation of CKD as a cardiovascular risk equivalent in patients >65 years of age appears justified.