Background: Diabetes mellitus has been recognized as a strong predictor of heart failure (HF) in patients with acute myocardial infarction (AMI). However, considerable controversy exists regarding the pathogenetic mechanisms of HF after AMI in diabetic patients. We hypothesized that the increased incidence of HF in diabetic patients was associated with a greater propensity for left ventricular (LV) remodeling.
Methods and results: A series of 325 patients (42 diabetics) with AMI successfully treated with primary angioplasty underwent serial 2D echocardiography from admission to 1 and 6 months and 6-month angiography. No significant difference was found between diabetics and nondiabetics regarding baseline clinical, angiographic, and echocardiographic characteristics, as well as 6-month restenosis and reocclusion rates. At 6 months, a similar incidence of LV remodeling was observed in diabetics and nondiabetics (33% versus 25%; P=0.234), with similar patterns of changes in LV volumes and LV global and regional systolic function. At 5 years, the incidence of HF was higher in the diabetics (43% versus 20%, P=0.001). Diabetes was found to be an independent predictor of HF at 5 years (hazard ratio, 1.8; P=0.0366). However, LV remodeling was predictive of HF in the nondiabetics (P=0.023) but not in the diabetics (P=0.123). In a subgroup of patients, higher LV chamber stiffness (as assessed by echocardiography) was detected in the diabetics with HF.
Conclusions: The more frequent progression to HF in the diabetics after AMI is not explained by a greater propensity for LV remodeling. Other factors, such as diastolic dysfunction, may play a role.