Critique 006: Alcohol, mortality in patients with CVD

Critique 006: 2 June 2010

Subject:  Alcohol, mortality in patients with CVD

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Article:  Costanzo S, Di Castelnuovo A, Donati MB, Iacoviello L, de Gaetano G.   Contemporary Reviews in Cardiovascular Medicine.  Cardiovascular and overall mortality risk in relation to alcohol consumption in patients with cardiovascular disease.  Circulation 2010;121;1951-1959.

Overview of Paper

The authors state that alcohol, in striking contrast to tobacco and illicit drugs, is linked to an extensively documented J-shaped dose effect curve, with regular moderate consumption reducing cardiovascular and overall mortality, whereas excessive or binge drinking has the opposite effect.  Data indicative of a lower risk of cardiovascular events among moderate drinkers in apparently healthy people are extensive and consistent, whereas the role of alcohol intake among patients with cardiovascular disease (CVD) is less clear.

Recommendations about alcohol consumption in patients with previous CVD reflect experts’ consensus rather than circumstantial evidence.  For example, the US Food and Drug Administration warns that heart disease patients should stop drinking, and people who take aspirin regularly should not drink alcohol.   However, in the American Heart Association/American College of Cardiology guidelines for secondary prevention, CVD patients are encouraged to maintain a lifestyle that includes drinking alcohol in moderation. The “Diet and Lifestyle Recommendations” scientific statement from the American Heart Association Nutrition Committee advises, “If you consume alcohol, do so in moderation (equivalent of no more than 1 drink in women or 2 drinks in men per day).  The latter statement is largely accepted within the scientific community, definitely when referring to healthy people, although some would advise people to abstain completely rather than encouraging them to drink small amounts regularly.  It has in fact been suggested that the consumption of alcohol for certain health benefits should not be encouraged because the harm would far outweigh the gain, especially among poor populations and in low-income countries, where the disease burden per unit of alcohol consumption is greater.” 

In this paper, the authors review the evidence on the beneficial or harmful effects of alcohol in patients who have experienced a first cardiovascular event and briefly discuss the major mechanisms underlying the relationship.  They point out that abuse of alcohol, binge drinking, and drinking outside meals have all been associated with detrimental effects.  The authors also discuss limitations inherent in observational studies of alcohol and health and disease. 

As for implications for practice and policy, they state that their review “provides reasonable evidence that regular and moderate alcohol intake is significantly associated with a reduction in the incidence of secondary cardiovascular and all-cause mortality in patients with a history of CVD.”  However, when it comes to formulating alcohol policy based on these results, they point out that there are marked differences in the patterns of drinking among countries, especially when comparing drinking patterns between Mediterranean countries and those of Northern Europe and Russia.  Hence, they state that “in some low-income populations and poor countries, even if the net effect on CVD might be beneficial, the effect of alcohol on the overall burden of disease might be detrimental because of more frequent uncontrolled alcohol-use disorders, cancer, liver cirrhosis, and injury.”  In their conclusions, they warn against heavy or excessive drinking but state that regular moderate drinkers “need not be told to modify their drinking habits.”    

Forum Comments

This review paper for Circulation, the official journal of the American Heart Association, summarizes data from 8 epidemiologic studies of subjects with cardiovascular disease (CVD) as to subsequent mortality (both CV and total-mortality) according to alcohol consumption.  The number of subjects ranged from 262 (Valmadrid) to more than 5,000 (Muntwyler), with follow up ranging from 1.1 year (Masunaga) to more than 12 years (Valmadrid and Shaper).  Most of the studies showed showed significantly lower risk of both CV and total mortality for patients with CVD who were consumers of alcohol. 

This paper, a Contemporary Review, aims to help physicians reach the best care decision for a given population.  It can be useful when applied appropriately.  But it is important that advice be individualized: an older patient showing high risk of CVD and no risk of dependence will surely be given different advice that a young person without risk factors.  Guidelines are neither infallible nor a substitute for clinical judgment.

Despite the rather impressive findings of lower subsequent risk of death for CVD patients who continue to consume alcohol, the authors were very cautious in their conclusions, which do not seem to follow logically from their results.  The authors focus on the dangers of excessive drinking and not encouraging cardiovascular patients who do not drink to start regular drinking, adding that “Alcohol is not recommended for young people (who are generally at very low risk of CVD), pregnant women, those at risk of alcoholism, or anyone whose activity calls for concentration, skill, or coordination.”  While these admonitions may be true, they have little to do with the topic of this paper: survival among patients with CVD according to their alcohol consumption. 

It is interesting that these authors published the meta-analysis upon which this review is largely based in the Journal of the American College of Cardiology earlier in 2010.¹  In that paper, their conclusions were less restrained: “Cardiologists should be aware that regular, moderate alcohol consumption, in the context of a healthy lifestyle (increased physical activity, no smoking), dietary habits (decreased dietary fat intake, high consumption of fruit and vegetables), and adequate drug therapy, would put their patients at a level of cardiovascular or mortality risk substantially lower than either abstainers or heavy or binge drinkers.

The following is a comment from the senior author of this report, Giovanni de Gaetano, MD, PhD, Head, Research Laboratories, “John Paul II” Center for High Technology Research and Education in Biomedical Sciences, Catholic University, Campobasso, Italy:

“When I obtained my MD degree, many years ago, three were the advices given to a patient who had suffered an acute myocardial infarction: don’t smoke, don’t drink and take complete bed rest for one month.  Today the first advice only is still valid.  Our review paper in Circulation offers a balanced but strong support to the benefit of moderate alcohol drinking after an AMI.  In our conclusions we suggest not to advice abstainers to start drinking after an AMI, but to encourage those who were already drinkers before the event not to stop moderate drinking.  It is too a prudent approach?  We do believe that drinking should not be considered as a drug to be prescribed to prevent recurrency, but a lifestyle that may protect against cardiovascular risk.  Obviously, a cardiologist should inform his AMI patient that moderate drinking might offer him a better health perpective than being an abstainer.  He must certainly give him a strong advice, if it is the case, to stop heavy and/or irregular (binge) drinking”

Reference from Forum Critique

1.  Costanzo S, Di Castelnuovo A, Donati MB, Iacoviello L, de Gaetano G.  Alcohol consumption and mortality in patients with cardiovascular disease.  A meta-analysis.  J Am Coll Cardiol 2010;55:1339–1347
 

Lay Summary

This review paper for the American Heart Association summarizes data from 8 epidemiologic studies of subjects with cardiovascular disease (CVD) as to their subsequent mortality (both CV and total-mortality) according to their alcohol consumption.  Most studies showed lower risk of both CV and total mortality for patients with CVD who were consumers of alcohol.

Despite these findings, the authors were very “cautious” in their conclusions, focusing on the dangers of excessive drinking and not encouraging cardiovascular patients who do not drink to start regular drinking. It is interesting that these authors published the meta-analysis upon which this review is largely based in the Journal of the American College of Cardiology just two months ago.  In that paper, their conclusions were less restrained: “Cardiologists should be aware that regular, moderate alcohol consumption, in the context of a healthy lifestyle (increased physical activity, no smoking), dietary habits (decreased dietary fat intake, high consumption of fruit and vegetables), and adequate drug therapy, would put their patients at a level of cardiovascular or mortality risk substantially lower than either abstainers or heavy or binge drinkers.”  

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Contributions to this critique by the International Scientific Forum on Alcohol Research were made by

R. Curtis Ellison, MD, Section of Preventive Medicine & Epidemiology, Boston University School of Medicine, Boston, MA, USA

Harvey Finkel, MD, Hematology/Oncology, Boston University Medical Center, Boston, MA, USA

Giovanni de Gaetano, MD, PhD, “John Paul II” Center for High Technology Research and Education in Biomedical Sciences, Catholic University, Campobasso, Italy

Francesco Orlandi, MD, Dept. of Gastroenterology, Università degli Studi di Ancona. Italy