Incidence, Predictors, and Subsequent Mortality Risk of Recurrent Myocardial Infarction in Patients Following Discharge for Acute Myocardial Infarction

Abstract

In the percutaneous coronary intervention (PCI) era, little evidence exists regarding the incidence, predictors and long-term mortality of recurrent myocardial infarction (Re-MI) following discharge for acute myocardial infarction (AMI). A total of 7,870 patients who survived AMI were studied with a median follow-up period of 3.9 years: 353 patients (4.5%) experienced Re-MI, with 7 of those dying within 30 days, which was classified as fatal Re-MI. The incidence of Re-MI per year was 2.65% for the first year, and 0.91-1.42% thereafter up to 5 years. Multivariate Cox regression analyses revealed that predictors of Re-MI were diabetes mellitus (hazard ratio (HR): 2.079, P<0.001), history of MI (HR: 1.767, P=0.001), and advanced age (HR: 1.021, P=0.001). These 3 predictors remained significant when angiographic and procedural parameters were incorporated into the analyses. The incidence and adjusted risk of Re-MI increased when these variables were clustered (P<0.001). The all-cause mortality rate was significantly higher in patients with Re-MI than in those without (HR: 2.206, P<0.001). In post-AMI patients treated in the PCI era, the incidence of Re-MI is low compared with that reported during the past 30 years. Patients' clinical factors of diabetes mellitus, history of MI, and advanced age appear to affect the occurrence of Re-MI after hospital discharge, and Re-MI still carries a risk for subsequent mortality.