Predictors of late development of heart failure in stable survivors of myocardial infarction

OBJECTIVES: We sought to determine the predictors of heart failure (HF) development in long-term survivors of myocardial infarction (MI). BACKGROUND: Modern strategies of acute MI care have resulted in an increasing proportion of survivors at heightened risk of future non-fatal events, including HF. METHODS: We assessed the risk of developing HF in 3860 stable MI patients without a previous history of HF, who were enrolled in the Cholesterol And Recurrent Events (CARE) trial a median of 10 months post MI. Baseline characteristics of patients who did or did not develop HF during the five years of observation were assessed. RESULTS: A total of 243 patients (6.3%) developed HF in a linear pattern at a rate of 1.3%/year. Heart failure development markedly increased the risk of death (hazard ratio 10.2, 95% confidence interval 7.7 to 13.5). Fifty-seven patients (23.5%) who developed HF had a recurrent MI between enrollment and the onset of HF, increasing the risk fivefold. The most important predictors of HF were age and left ventricular ejection fraction. Other predictors included diabetes, history of hypertension, previous MI, and baseline heart rate. Moderate exercise three or more times per week was independently associated with a 30% lower risk of HF. CONCLUSIONS: Heart failure post MI occurs in a time-dependent fashion, which is usually not a direct consequence of a detectable interim MI. Patients who experience late-onset HF have a 10-fold increased risk of death compared with other MI survivors. Baseline characteristics can risk stratify patients at high risk of subsequent HF.