Moderate Drinking May Not Be Harmful in Heart Failure

Batya Swift Yasgur, MA, LSW

December 28, 2018

People over age 65 years with a new diagnosis of heart failure (HF) can drink moderate amounts of alcohol without exacerbating their condition, new research suggests.

Investigators analyzed data from the Cardiovascular Health Study between 1989 and 1993 on close to 6000 older adults with an average age of 79 years. They compared patients who never drank, patients who drank in the past but stopped, patients who had seven or fewer drinks per week, and patients who had eight or more drinks per week.

After controlling for demographic, lifestyle, and health variables, the researchers found an association between consuming up to seven drinks per week and an extended survival for just over 1 year (383 days), compared with those who abstained from drinking altogether.

"Studies like this don't prove cause and effect, only association, but the most conservative interpretation of the data is that people who continue to drink in moderation after a diagnosis of HF are probably not harmed and may even see a benefit," senior author David Brown, MD, professor of medicine, Washington University School of Medicine, St Louis, told theheart.org | Medscape Cardiology.

"However, the other message that's important is that this doesn't mean people who never drank alcohol and then developed HF should start drinking," he warned.

The study was published online December 28 in JAMA Network Open.

A Patient's Question

"The study was motivated by a question from a patient I took care of about 6 years ago who was admitted to hospital with a new diagnosis of HF," Brown reported.

"The patient told me that he liked a cocktail or two in the evenings, and he wanted to know whether he would now have to stop drinking alcohol," he continued.

"I told him that my instinct was that drinking alcohol in moderation was okay, although we know that there are toxic effects of excessive drinking that can contribute to HF," he recounted.

"I told my patient that I would peruse the medical literature to see what the data show and discovered there were no data specifically to help us guide patients who drink moderately and have just been diagnosed with HF."

To investigate the question, Brown and colleagues collected data from the Cardiovascular Health Study, a prospective cohort study of 5888 black and white US adults aged ≥ 65 years who had baseline clinical examinations from 1989 through 1993, followed by nine annual clinic visits.

Only patients with incident HF diagnosed during the first 10 years were included in the analysis.

"We did not limit our analysis to any particular type of alcohol, whether beer, wine, or hard liquor, but referred to them by drinks per week," Brown noted.

A serving of alcohol was defined as a 12-oz beer, a 6-oz glass of wine, or a 1.5-oz shot of liquor.

Based on the first available measure of alcohol consumption following the initial HF diagnosis, study participants were then divided into four categories: abstainers; former drinkers; patients consuming seven or fewer alcoholic drinks per week, and patients consuming more than seven drinks per week.

The researchers chose a cutoff of seven drinks per week because this is the recommended maximum alcohol consumption for this age group.

The group of former drinkers was then excluded from the analysis because "they do not constitute an ordinal category of alcohol consumption," the authors explain.

Additionally, former drinkers may have discontinued in response to changes in health ("sick quitters"), and the researchers were "interested in examining how continued alcohol consumption after a diagnosis of HF was related to survival, compared with long-term abstinence."

The analysis was adjusted for multiple variables, including age, race/ethnicity, education level, income, smoking status, and marital status.

Health-related variables included hypertension, diabetes, stroke, myocardial infarction, atrial fibrillation, and body mass index. The researchers also adjusted for use of medications such as beta-blockers and angiotensin-converting enzyme inhibitors.

Protective Effect

Of the participants, 393 were diagnosed with incident HF (54.2% women; 86.3% white; mean [SD] age, 78.7 [6.0] years).

Of these, 42.7% were abstainers, 24.4% were former drinkers, 28.5% were current drinkers consuming one to seven drinks per week, and 4.3% were current drinkers consuming more than seven drinks per week.

Of the 393 participants, only 5.6% lived throughout the entire follow-up period.

Across all alcohol consumption categories, the percentage of men, white individuals, high-income participants, and individuals with more years of education increased with increasing alcohol consumption (all P < .001 for trend).

On the other hand, diabetes was less common across the alcohol consumption categories (P = .01 for trend).

Additionally, there were fewer never smokers and more former smokers (P < .001 and P = .006 for trend, respectively).

The mean 15-ft walk time was lowest (5 seconds; IQR, 4.0-7.0 seconds]) in the moderate-consumption group (seven or fewer drinks per week), indicating better fitness.

After controlling for other factors, consumption of seven or more alcoholic drinks per week was associated with additional mean survival of 383 days (95% CI, 17 - 748 days; P = .04) compared with abstinence from alcohol.

The researchers found a "significant inverted U-shaped association" between alcohol consumption and survival, although the small number of individuals who consumed more than seven drinks per week (n = 17) limited the "robustness" of the findings.

Multivariable model estimates of mean time from HF diagnosis to death for never drinkers, consumers of seven or fewer alcoholic drinks per week, and consumers of more than seven drinks per week were 2640 (1967-3313), 3046 (2372-3719), and 2806 (1879-3734) days, respectively (P = .02).

Interestingly, consumption of 10 drinks per week was associated with the longest survival after HF diagnosis (mean, 3381 [2806-3956] days).

"Although mixed associations of alcohol use and mortality have been observed in individuals with prevalent left ventricular dysfunction or HF, the current study is unique to date because it analyzed survival in an inception cohort with HF and it distinguished between former drinkers and abstainers," the authors state.

"No one knows what might confer this protective benefit, although there is some evidence that alcohol may affect the clotting of the blood and exert a very mild anticoagulant effect that may protect people [with HF]," Brown commented.

"At least in beer and wine, there are some antioxidant compounds, which may have a protective effect," he said.

"But the fact that protection also came from pure alcohol — vodka — suggests that at least part of the effect may be something that's directly coming from the alcohol molecule without other things included in the mixtures we refer to as 'beer' and 'wine,'" Brown suggested, adding that these explanations remain "pure speculation" at this point.

Light Drinking "Reasonable"

Commenting on the study for theheart.org | Medscape Cardiology, Gregg C. Fonarow, MD, who was not involved with the study, observed that patients with new onset HF "used to be advised to abstain completely from alcohol consumption based on the concept that any level of alcohol may impact cardiac function." Fonarow is the Eliot Corday Professor of Cardiovascular Medicine and Science, director, Ahmanson-UCLA Cardiomyopathy Center, and codirector, UCLA Preventative Cardiology Program, David Geffen School of Medicine.

"This new study finds that, compared to never drinkers of alcohol, those with use limited to seven to 10 alcohol-containing drinks a week was associated with lower mortality risk."

However, he cautioned, "it is important to note that this is an observational study and not a randomized clinical trial, such that some of these findings may have been influenced by other differences in those HF patients that did and did not consume alcoholic beverages," cautioned Fonarow, who is also cochief of clinical cardiology, UCLA Division of Cardiology.

"While excessive levels of alcohol consumption should be avoided and those patients with alcohol-related cardiomyopathy should abstain, this study reinforces current recommendations that light alcohol consumption may be reasonable in the setting of new onset and established HF," he added.

Brown emphasized that the decision of patients with HF to continue or discontinue drinking "should always be made in consultation with their doctors."

The study was supported by the National Heart, Lung, and Blood Institute, National Institute of Neurological Disorders and Stroke, and National Institute on Aging. Brown has disclosed no relevant financial relationships. Disclosures for other authors are listed on the original paper. Fonarow is a consultant to Abbott, Bayer, Janssen, Novartis, and Medtronic, and has reported no conflicts of interest relevant to his comments.

JAMA Netw Open. Published online December 28, 2018. Abstract

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