Chronic Alcohol Intake Exacerbates Cardiac Dysfunction After Myocardial Infarction

Abstract

Abstract Aims Alcohol intake is a risk factor for cardiovascular diseases. This study was designed to investigate whether chronic alcohol intake affects myocardial infarction (MI)-induced cardiac remodeling and heart failure. Methods Eight-week-old male C57BL/6 mice were randomly divided into four groups: Sham group (Sham), MI plus drinking water group (MI + Vehicle), and MI plus daily alcohol intake for 6 weeks with or without gavage of additional alcohol every 3 days (MI + Alcohol and MI + Alcohol + G). The MI were induced by permanent left anterior descending (LAD) coronary artery ligation surgery before vehicle or alcohol treatment. The blood alcohol concentration (BAC), cardiac function, release of cardiac enzymes, pathological changes and mitochondrial function were measured. Results As expected, supplementation of alcohol in drinking water significantly increased random BAC in mice. Long-term exposure to alcohol further reduced body weight, ejection fraction and fractional shortening in comparison with the MI + Vehicle group. Histopathological data showed that alcohol increased fibrosis in infarct zone, which was well correlated with the functional decline. Also, as compared to the MI + Vehicle group, the adenosine diphosphate-supported respiratory function of freshly isolated cardiac mitochondria was inhibited in the MI + Alcohol + G group. Besides, upon MI-induced cardiac damage, we did not observe further changes in heart weight, cardiomyocyte enlargement in remote zone, exercise capacity, lung edema and the release of cardiac enzyme after chronic alcohol intake. Conclusions Our study demonstrated that chronic daily alcohol exposure exacerbated MI-induced cardiac dysfunction, which is related to promoted myocardial fibrosis and inhibited mitochondrial function.