Marijuana Use May Boost Risk of Weakened Heart Muscle, Study Finds

Four more states, including California, approved recreational marijuana use Tuesday, which means 8 states and the District of Columbia will allow adults to use a substance once illegal. But a study presented Sunday finds that frequent marijuana use may put young men at risk of a heart malfunction that mimics a heart attack, even among those who are otherwise at little risk of cardiac problems.

The study, presented at the 2016 Scientific Session of the American Heart Association, examined a national data set to show that the risk of stress cardiomyopathy doubled among young men who smoked marijuana. Cardiomyopathy is a sudden, usually temporary, weakening in the heart muscle that affects its ability to pump, causing pain and shortness of breath. As the results showed, it is more often seen among older women.

With more states loosening up laws on marijuana use, the results from Saint Luke’s University Hospital in Bethlehem, Pennsylvania, should give public officials pause, the researchers said. “This development of stress cardiomyopathy in younger patients who used marijuana suggests a possible link that needs to be further investigated,” said Sahil Agrawal, MD, a study co-author and chief cardiology fellow at St. Luke’s.

Researchers looked at records from 33,343 people identified in the Nationwide Inpatient Sample who were hospitalized with cardiomyopathy between 2003 and 2011 in the United States. Of this group, 210, or less than 1%, were identified as marijuana users.

Compared with those who were not using marijuana, this small group was more likely to be younger and more likely to be male: the average age of marijuana users was 44, compared with 66 for other cardiomyopathy patients; 36% of the marijuana users were male compared with just 8% of the others.

The marijuana users had fewer risk factors, such as high blood pressure (38% vs 62%), diabetes (2.4% vs 17.6%), or hyperlipidemia (15.7% vs 52.4%), to explain this event. However, the marijuana users were more likely to suffer mental health disorders, with higher rates of depression (32.9% vs 14.5%), psychosis (11.9% vs 3.8%), anxiety disorder (28.4% vs 16.2%), and alcoholism (13.3% vs 2.8%). The marijuana users were also far more likely to use tobacco (73.3% vs 38.6%) and multiple substances (11.4% vs 0.3%); all P <.001.

How does marijuana cause stress on the heart? In their presentation, the research team said that cardiomyopathy, also called, “transient ventricular regional ballooning,” occurs when there is sudden dysfunction in the left ventricle, with or without involvement of the right ventricle. The heart muscle weakens despite the lack of a blockage normally associated with coronary artery disease.

Stress hormones are known to play a role in these sudden attacks, and cannabis apparently plays a role in the body’s response to these hormones. Endocannabinoid receptors are found in the heart muscle, and the researchers suspect they play a role in the onset of these heart malfunctions.

The study also found that marijuana users were more likely to suffer cardiac arrest, and that marijuana use itself could be an independent predictor of heart problems among young men.

Amitoi Singh, MD, the study’s lead author and chief cardiology fellow at St. Luke’s University Health Network, said in a statement that the effects of marijuana on the cardiovascular are not well-known.

“If you are using marijuana and develop symptoms such as chest pain and shortness of breath, you should be evaluated by a healthcare provider to make sure you aren’t having stress cardiomyopathy or another heart problem,” Singh said.

The CDC reports that marijuana use is steadily increasing in the United States. In September, an analysis found than in 2014, there were an average of 7000 new users per day.

Reference

Singh A, Agrawal S, Fegley M et al. Marijuana (Cannabis) use is an independent predictor of stress cardiomyopathy in younger men. Presented at the 2016 Scientific Session of the American Heart Association. November 13, 2016. Poster S4054.