Factors Associated with Recurrent Coronary Events Among Patients with Cardiovascular Disease

Abstract

To determine which factors are associated with recurrent coronary events. Matched, case-control study. Electronic databases of a health maintenance organization. Of a cohort of adults (mean age 62 yrs, 68% male) who had an incident coronary event, defined as acute myocardial infarction or percutaneous coronary intervention, between January 1, 1999, and June 30, 2004, who survived and who were enrolled in a cardiac risk reduction service within 90 days after the incident event, 259 cases (patients who had a recurrent event between 90 days after the incident event and December 31, 2005) were matched with 688 controls (patients who did not have a recurrent event within this time frame). Multivariate conditional logistic regression was used to identify predictors of a recurrent coronary event. Although classic cardiac risk factors and drug therapies were similar for both groups at the time of the incident event, the mean low-density lipoprotein cholesterol (LDL) level, non-high-density lipoprotein cholesterol (non-HDL) level, and LDL:HDL ratio were higher and HDL levels were lower in the case patients compared with control patients (p<0.001) at the time of the case patients' recurrent events. More case patients received a statin but at a lower dose, defined as less than 40 mg of simvastatin equivalent (cases 45% vs controls 31%, p<0.001). Factors associated with a recurrent event included higher chronic disease score (odds ratio [OR] 1.1, 95% confidence interval [CI] 1.0-1.2), higher LDL:HDL ratio (OR 2.2, 95% CI 1.5-3.3), and statin dose less than 40-mg simvastatin equivalent (OR 2.9, 95% CI 1.8-4.9). These results support use of a statin at moderate-to-high doses as the basis of therapy for secondary coronary event prevention. The LDL:HDL ratio may help determine the degree of LDL lowering beyond traditional treatment goals.