Increased Mortality Associated With Low Use of Clopidogrel in Patients With Heart Failure and Acute Myocardial Infarction Not Undergoing Percutaneous Coronary Intervention: A Nationwide Study

Abstract

We studied the association of clopidogrel with mortality in acute myocardial infarction (AMI) patients with heart failure (HF) not receiving percutaneous coronary intervention (PCI). Use of clopidogrel after AMI is low in patients with HF, despite the fact that clopidogrel is associated with absolute mortality reduction in AMI patients. All patients hospitalized with first-time AMI (2000 through 2005) and not undergoing PCI within 30 days from discharge were identified in national registers. Patients with HF treated with clopidogrel were matched by propensity score with patients not treated with clopidogrel. Similarly, 2 groups without HF were identified. Risks of all-cause death were obtained by the Kaplan-Meier method and Cox regression analyses. We identified 56,944 patients with first-time AMI. In the matched cohort with HF (n = 5,050) and a mean follow-up of 1.50 years (SD = 1.2), 709 (28.1%) and 812 (32.2%) deaths occurred in patients receiving and not receiving clopidogrel treatment, respectively (p = 0.002). The corresponding numbers for patients without HF (n = 6,092), with a mean follow-up of 2.05 years (SD = 1.3), were 285 (9.4%) and 294 (9.7%), respectively (p = 0.83). Patients with HF receiving clopidogrel demonstrated reduced mortality (hazard ratio: 0.86; 95% confidence interval: 0.78 to 0.95) compared with patients with HF not receiving clopidogrel. No difference was observed among patients without HF (hazard ratio: 0.98; 95% confidence interval: 0.83 to 1.16). Clopidogrel was associated with reduced mortality in patients with HF who do not undergo PCI after their first-time AMI, whereas this association was not apparent in patients without HF. Further studies of the benefit of clopidogrel in patients with HF and AMI are warranted.