Cannabis use was associated with an increased risk of cerebrovascular accidents and heart failure in a retrospective analysis of the Nationwide Inpatient Sample (NIS).

Aditi Kalla, MD, a cardiology fellow at Einstein Medical Center in Philadelphia, and her colleagues analyzed data from nearly 21 million adult patients aged 18-55 years from the NIS 2009-2010 database. Approximately 1.5% (316,397) were diagnosed as cannabis users.

Cannabis users were significantly more likely to experience heart failure (1.4% vs. 1.2% of nonusers), cerebrovascular accident (1.03% vs. 0.62%), coronary artery disease (5% vs. 4.6%), sudden cardiac arrest (0.21% vs. 0.17%), and atrial fibrillation (1.1% vs. 1.0%).

Cannabis users also were more likely to report cardiac risk factors such as hypertension (19.9% vs. 15.7% of nonusers), tobacco use (47.2% vs. 11.4%), alcohol use (28.1% vs 3.8%), and obesity (7% vs. 6.5%). They were older, on average, with a mean age of 33 years, compared with 26 years, and were likely to be male (60%), Dr. Kalla noted during a press briefing held in advance of the annual meeting of the American College of Cardiology.

Using multivariate regression analysis to adjust for these traditional cardiovascular risk factors, the investigators found cannabis remained an independent predictor for heart failure, with an odds ratio of 1.1 (P less than .01) and cerebrovascular accident, with an OR of 1.24 (P less than .001).

“Even when we corrected for known risks, we still found a higher rate of both stroke and heart failure in these patients,” Dr. Kalla said. “That leads us to believe that there is something else going on besides just obesity or diet-related cardiovascular side effects.”

Dr. Kalla noted that an expert analysis published by the ACC in September 2016 linked cannabinoid receptor type 1 with atherogenesis.

Further research is needed on the topic of cannabis and cardiovascular effects, especially as the legalization of medical and recreational cannabis spreads across the country, Dr. Kalla said. “Decriminalization of cannabis has passed in several states, bringing the total count now up to 28 states, plus the District of Columbia. We now need to be more knowledgeable of the risks and benefits of cannabis, as patients in these states may inquire into the use of it, or even ask us for prescriptions for it.”

While the NIS provided a large and strong data set for this analysis, the number of cannabis users likely was underreported because cannabis was legal in just 14 states at the time, Dr. Kalla noted. The study also was limited by a lack of specific information regarding cannabis intake, method of intake (ingestion or smoking), quantity and frequency of use, and whether use was medical or recreational.

The information collected also excluded whether patients used marijuana for medical or recreational purpose and how it was taken, by smoking or ingestion.

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