Background: Aging and diabetes mellitus have been recognized as strong predictors of heart failure in patients with acute myocardial infarction. The aim of this study was to assess, by echocardiography, the influence of aging and non-insulin-dependent diabetes mellitus on the changes of left ventricular parietal kinesis in patients with acute myocardial infarction over the 6 months after hospitalization.
Methods: The study population consisted of 82 patients (42 male, 40 female) aged 70 years, consecutively admitted to coronary care unit with acute myocardial infarction from January 1991 to May 1993. They were divided into two groups: group 1 comprised 36 patients with non-insulin-dependent diabetes mellitus, aged 78.8 +/- 6.02 years, 17 men and 19 women; group 2 comprised 46 patients without diabetes aged 78.7 +/- 6.9 years, 25 men and 21 women. Echocardiography was performed at admission to the unit (T0), at discharge (T1), and after 6 months of follow-up (T2). The echocardiographic wall motion score index was calculated by considering the number of akinetic and dyskinetic left ventricular wall segments. Fatal and non-fatal incidents of heart failure were also considered and a multivariate analysis was applied to identify the clinical and instrumental parameters that were independent predictors of wall motion score index changes and heart failure events.
Results: At T1 the two groups were comparable in localization of acute myocardial infarction, previous myocardial infarction, creatinine kinase serum peak, ECG score and wall motion score index. A statistically significant reduction in akinesia (P < 0.001) was observed in group 2 at T1 and T2, but was not seen in group 1. At T2 the difference in wall motion score index between the groups became significant (P < 0.05). The occurrence of heart failure was significantly higher in group 1 than in group 2 either during hospitalization (P < 0.03) or during follow-up (P < 0.004). The multivariate analysis identified non-insulin-dependent diabetes mellitus as an independent predictor of lacking recovery in LV kinesis (P < 0.01) and of heart failure development (P < 0.001).
Conclusion: In elderly patients with non-insulin-dependent diabetes mellitus lack of recovery in wall motion score index after acute myocardial infarction seems to be an important factor, with a higher heart failure prevalence adversely affecting the in-hospital and long-term outcome. Non-insulin-dependent diabetes mellitus appears to be an important factor related to this unfavorable outcome.