Impact of diabetes mellitus on outcomes in patients with myocardial infarction according to varying degrees of left ventricular systolic dysfunction

Abstract

Background: Diabetes mellitus (DM) is known to contribute to unfavorable short- and long-term outcomes in patients with myocardial infarction (MI). Particularly poor outcomes are associated with left ventricular systolic dysfunction after an MI. Our study aimed to compare the short- and long-term outcomes of MI in patients with DM and varying degrees of left ventricular systolic dysfunction with the corresponding outcomes in a non-diabetic control group. Methods: This analysis focused on patients with MI registered in the Polish National Registry of Acute Coronary Syndrome between 2009 and 2011. For this analysis, diabetic patients were additionally stratified into three subgroups depending on the degree of left ventricular systolic dysfunction, as assessed during their hospitalization for MI. Subsequently, the 30-day, 12-month, and 36-month outcomes in the diabetic study subgroups were compared with those in the corresponding non-diabetic subgroups. Results: This analysis encompassed a nationwide cohort of 58 123 patients. Twelve- and 36-months mortality was greater in diabetic patients than in non-diabetic patients. The highest 36-months mortality (46.64%) was in the group of patients with DM and reduced ejection fraction (EF) <40%. Multivariate analysis showed diabetes and low EF to be independent risk factors for 36-month mortality, increasing the risk of death by 35% for diabetes and by 30% for each 5-percentage point EF decrease. Higher mortality was observed in older patients, smokers, and patients with ischemic heart disease before the index hospitalization. Conclusions: Both diabetes and reduced EF proved to be independent risk factors for increased mortality over a long-term follow-up after MI.