Aims: The mechanisms underlying the higher risk of heart failure after myocardial infarction (MI) in diabetic patients remain incompletely understood. Our aim was to investigate cardiac remodeling after MI according to diabetic status.
Methods: Data from 512 patients with a first anterior MI included in two prospective cohorts on left-ventricular remodeling were analyzed. Echocardiographic studies were performed before discharge, at 3 months and at 1 year. Clinical follow-up was performed after 3 years.
Results: There were 60 (23%) diabetic patients in cohort 1 and 51 (21%) in cohort 2. Therapeutic strategies, infarct size and residual left-ventricular ejection fraction did not differ between diabetic and nondiabetic patients. In both cohorts, there was a significant increase in left-ventricular volumes and a recovery in left-ventricular systolic function from baseline to 1 year; these parameters did not differ according to diabetic status at any of the three time points. Diastolic function was analyzed in cohort 2: the E/Ea ratio was higher in diabetic patients at baseline and during follow-up. Diabetes mellitus was an independent predictor of cardiovascular death or rehospitalization for heart failure in cohort 1 [relative risk (RR) 2.62 (1.35-5.11)] and in cohort 2 [RR 4.99 (2.06-12.21)].
Conclusions: In patients with a modern treatment of MI, diabetes mellitus remains a major and independent predictor of subsequent heart failure. This higher risk is not associated with a decreased left-ventricular systolic function or with increased left-ventricular remodeling. The evidence of higher left-ventricular filling pressures suggests left-ventricular diastolic dysfunction as a potential mechanism.