Alcohol is often cited to be a common cause of cardiomyopathy and heart failure. However, in most available population-based studies, a modest-to-moderate alcohol consumption has been associated with favorable effects on the cardiovascular system, including a lowered risk of heart failure, compared with no alcohol consumption. Available genetic epidemiological data have not supported a causal association between alcohol consumption and heart failure risk, suggesting that alcohol may not be a common cause of heart failure in the community. Data linking alcohol intake with cardiomyopathy risk are sparse, and the concept of alcoholic cardiomyopathy stems mainly from case series of selected patients with dilated cardiomyopathy, where a large proportion reported a history of excessive alcohol intake. This state-of-the-art paper addresses the current knowledge of the epidemiology of alcoholic cardiomyopathy and the role of alcohol intake in patients with non-alcohol-related heart failure. It also offers directions to future research in the area. The review questions the validity of current clinical teaching in the area. It is not well known how much alcohol is needed to cause disease, and the epidemiological pathways linking alcohol consumption to cardiomyopathy and heart failure are not well understood. Until more evidence becomes available, caution is warranted before labeling patients as having alcoholic cardiomyopathy due to a risk of neglecting other contributors, such as genetic causes of cardiomyopathy. In non-alcohol-related heart failure, it is unknown whether total abstinence is improving outcomes (compared with moderate drinking). Ideally, randomized clinical trials are needed to answer this question.
BACKGROUND: Studies evaluating alcohol consumption and cardiovascular diseases have shown inconsistent results. METHODS: We performed a systematic review of peer-reviewed publications from an extensive query of Ovid MEDLINE, Ovid Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from database inception to March 2022 for all studies that reported the association between alcohol consumption in terms of quantity (daily or weekly amounts) and type of beverage (wine, beer or spirit) and cardiovascular disease events.
RESULTS: The study population included a total of 1,579,435 individuals based on 56 cohorts from several countries. We found that moderate wine consumption defined as 1-4 drinks per week was associated with a reduction in risk for cardiovascular mortality when compared with beer or spirits. However, higher risk for cardiovascular disease mortality was typically seen with heavier daily or weekly alcohol consumption across all types of beverages.
CONCLUSIONS: It is possible that the observational studies may overestimate the benefits of alcohol for cardiovascular disease outcomes. Although moderate wine consumption is probably associated with low cardiovascular disease events, there are many confounding factors, in particular, lifestyle, genetic, and socioeconomic associations with wine drinking, which likely explain much of the association with wine and reduced cardiovascular disease events. Further prospective study of alcohol and all-cause mortality, including cancer, is needed.