Does Toking Take a Toll on the Ticker?

Coronary artery disease risk examined in patients who smoke marijuana

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Smoking marijuana may increase the chances of heart attack immediately after use. For those who have had a heart attack, continued pot smoking may be linked to a shorter life span.

Previous research has shown a connection between heavy marijuana use and a greater likelihood of heart attack and stroke. A new study suggests a higher rate of death after acute heart attack in marijuana users, although results are statistically inconclusive.

"Stop smoking marijuana to lower your risk of possible heart attack."

Lauren Frost, MD, and Elizabeth Mostofsky, MPH, ScD, both from the Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School in Boston, led this project looking at the link between marijuana use and survival after a heart attack (myocardial infarction).

In previous research, these scientists demonstrated that the rate of heart attack is 4.8 times greater in the hour after marijuana use, compared with other times. Other studies have shown that pot smoking may lead to a temporary increase in high blood pressure and other negative health symptoms.

The doctors analyzed data on 2,097 patients, age 63 or younger, who had sustained a heart attack. There were 109 patients (5.2 percent) who reported marijuana use in the year prior to their heart attack.

Most of the pot users were younger, male, current smokers, heavy alcohol drinkers and unmarried.

Over 18 years of follow-up, 519 patients died, including 22 of the 109 who reported marijuana use at the time of their heart attack.

Compared with nonusers, the death rate was 29 percent higher with marijuana users.

While the data suggest a higher rate of mortality in marijuana users who have had a heart attack, investigators warn that the numbers in the study were not large enough to have statistical relevance.

“Larger studies with repeated measures of marijuana use are needed to definitively establish whether there are adverse cardiovascular consequences of smoking marijuana among patients with established coronary heart disease,” wrote the authors.

“Given the prior evidence of acutely increased risk following each episode of smoking marijuana," they commented, "it seems prudent to caution patients with coronary heart disease and those at high risk for cardiovascular disease to abstain from smoking marijuana.”

The study was published in the February issue of the American Heart Journal. The work was supported by a training grant from the National Institutes of Health and the Harvard Medical School Scholars in Medicine Office.

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Review Date: 
February 4, 2013
Last Updated:
February 4, 2013