Report: Smoking Marijuana Can Be Hard on Your Heart

Cardiologists should warn patients about the potential risks of marijuana, including its effects when paired with commonly prescribed cardiovascular medications, according to a report published Monday. 

"Our review suggests that smoking marijuana carries many of the same cardiovascular health hazards as smoking tobacco," said Dr. Muthiah Vaduganathan of Brigham and Women's Hospital's Heart and Vascular Center in Boston, the lead author of the review published in the Journal of the American College of Cardiology.

The authors of the report estimate more than two million cardiovascular disease patients who use marijuana or have used it before, including both recreational and medicinal uses. 

"Some observational studies have suggested an association between marijuana and a range of cardiovascular risks," Vaduganathan said. "We also know that marijuana is becoming increasingly potent . . . while the level of evidence is modest, there's enough data for us to advise caution in using marijuana for our highest-risk patients, including those who present with a heart attack or new arrhythmia, or who have been hospitalized with heart failure."

Statins and blood thinners can be affected by the use of marijuana, the review found. Statin levels can increase in the blood when marijuana is used, as can levels of blood thinners such as warfarin.

"The review provides detailed tables of many drugs administered for various cardiovascular conditions, with the anticipated effects of marijuana on each one," Vaduganathan said. "These will be helpful to cardiologists and pharmacists reviewing patients' medications and will help them collaboratively decide whether they need to adjust dosing if the patient continues to use marijuana."

The study's reviewers also suggested cardiologists screen patients for marijuana use and ask them how much they use and how they use it.

"Vaping marijuana is becoming more and more common, and we know vaping marijuana increases the pharmacological effects of the drug," Vaduganathan said.

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