Drinking Less Alcohol Improves Heart Function in People with Alcohol-Related Heart Failure

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The summary below is from the full report titled "The Effect of Controlled Drinking in Alcoholic Cardiomyopathy." It is in the 5 February 2002 issue of Annals of Internal Medicine (volume 136, pages 192-200). The authors are JM Nicolás, J Fernández-Solà, R Estruch, JC Paré, E Sacanella, A Urbano-Márquez, and E Rubin.

What is the problem and what is known about it so far?

Drinking alcohol heavily for several years can weaken the muscle walls of the heart. Weakened muscles then stretch, which enlarges the heart. A large, weakened heart cannot pump blood through the body normally. Symptoms such as fatigue, shortness of breath, and leg swelling result. Doctors call this serious disorder alcohol-related heart failure (alcoholic cardiomyopathy). Treatment with drugs can help symptoms, but heart transplant surgery is the only way for some people to improve their chances of living longer. Most doctors believe that people with alcoholic cardiomyopathy should avoid all alcohol. Experts have not agreed on whether reducing alcohol intake rather than completely abstaining from alcohol has any benefits. Better evidence is needed to resolve this uncertainty.

Why did the researchers do this particular study?

To describe effects of continued drinking on heart function in patients with alcoholic cardiomyopathy.

Who was studied?

The study included 55 men with alcoholic cardiomyopathy. All reported drinking at least 100 grams of alcohol (> 1 liter of wine, 10 twelve-ounce cans of beer, or 10 shots of 80-proof liquor) daily for at least 10 years. All had enlarged hearts and symptoms of heart failure. None had any reason to have heart failure other than heavy drinking.

How was the study done?

The researchers repeatedly urged the patients to stop drinking. Every year for 4 years, the atients had a complete check-up and tests of the heart's ability to pump blood [left ventricular ejection fraction]. The researchers put each man into one of four groups according to how much alcohol he reported drinking during the first year of the study: 1) those who did not drink at all; 2) those who practiced controlled moderate drinking [20 to 60 grams daily]; 3) those who drank heavily [60 to 80 grams daily]; and 4) those who abused alcohol (> 80 grams daily). The researchers compared heart function among the four groups.

What did the researchers find?

Heart function worsened in the 16 men who reported continued alcohol abuse (> 80 grams daily). Ten of these men died. Heart function improved in the 17 men who stopped drinking and the 15 men who reported controlled moderate drinking. Controlled moderate drinkers experienced improvement similar to that of men who did not drink at all. None of the men in these two groups died.

What were the limitations of the study?

Drinking amounts were self-reported and could have been underestimated. It is possible that factors other than the amount of drinking could have caused some of the observed changes in heart function. The study was small, and patients were followed for only 4 years. A larger, longer study is needed to show whether controlling drinking and quitting drinking have similar effects on chances of living longer.

What are the implications of the study?

Quitting drinking and decreasing drinking to a moderate amount (20 to 60 grams daily, or one to four drinks daily) improve heart function to the same degree in people with alcohol-related heart failure. Nevertheless, physicians should continue to recommend that alcoholic persons stop drinking altogether, since they may revert to alcohol abuse.