By Stephanie Riesenman for Heart1
On the topic of alcohol and heart failure, doctors have said for years that the two don’t mix. However, a new study suggests that heart attack survivors with decreased left ventricular function — a sign of heart failure risk —who consumed 1 to 10 alcoholic beverages a week, did not increase their risk of developing the condition over two years.
"Light-to-moderate alcohol consumption was neither beneficial nor detrimental in the outcomes of total mortality, total mortality and/or heart failure, recurrent [heart attack] and cardiovascular mortality," the researchers write in the current Journal of the American College of Cardiology.
Previous studies have shown that light-to-moderate drinking can lower the risk of death by as much as 20% to 30% in patients who have no known cardiovascular disease. Experts believe the benefit is achieved by lowering bad cholesterol and preventing platelets from clogging arteries. However, the American College of Cardiology/American Heart Association Guidelines for the Evaluation and Management of Chronic Heart Failure state that alcohol should be avoided by patients who are at high risk for developing chronic heart failure.
The study, led by Dr. David Aguilar, who was at Brigham and Women’s Hospital during the trial, and his colleagues from around the country and Canada, was one of the first to assess the effects of alcohol consumption in a population of heart attack survivors at risk for chronic heart failure. They relied on data collected from the Survival and Ventricular Enlargement, or (SAVE) Trial. That trial included 2,231 patients from 45 centers in the U.S. and Canada between 1987 and 1992. That study was designed to test the heart protective benefits of an ACE inhibitor in patients who’d survived a heart attack, and as a result had an ejection fraction of 40% or less. Ejection fraction is a measurement of how well the heart is pumping blood. This low percentage put them at risk for developing heart failure.
When patients entered the trial they were categorized according to their pattern of alcohol consumption 3 weeks prior to their heart attack. Those who had 1-10 drinks per week were called light-to-moderate drinkers, while those who had more than 10 drinks per week were considered heavy drinkers. The majority of participants were non-drinkers, while 32% were light-to-moderate, and 11% were heavy drinkers.
After 24 months, the researchers found that light-to-moderate alcohol consumption did not increase the risk of developing heart failure and that this group actually had a lower risk of developing heart failure than the non-drinkers and heavy drinkers. However, the non-drinkers tended to be older and heavier, and had a higher incidence of diabetes, high blood pressure, and worse ventricular function. When all these factors were considered, there was no difference in the risk of heart failure between the moderate drinkers and non-drinkers. The researchers warned that the data on the heavy drinkers was too limited to draw a strong conclusion about the risk of developing heart failure with more than 10 drinks a week.
"No significant benefit or risk was associated with heavy alcohol use, but the low number of individuals and events in this group prohibit definitive conclusions," the researchers write.
The researchers also want to point out that their study only looked at patients with a high risk of heart failure due to a previous heart attack, and did not include patients at risk for heart failure due to other reasons. But in the heart attack survivor population, the researchers suggest the current guidelines for alcohol consumption might need to be reevaluated.
"Although the limited data available support continued discouragement of heavy alcohol use in this population," the researchers write, "the totality of evidence suggests that light-to-moderate alcohol consumption is not associated with altered risk of developing chronic heart failure in patients with left ventricular dysfunction following [a heart attack.]"