Story at a glance

  • More than 2 million American adults with heart conditions say they’ve used marijuana.
  • The use of marijuana with statins and blood thinners can cause excessive bleeding or dangerous drops in blood pressure.
  • The review recommends cardiologists screen patients for marijuana use.

More than 2 million Americans with cardiovascular disease say they currently use or have used marijuana in the past, and now researchers say people with heart conditions may be at risk of cardiovascular issues when using pot.

A paper published in Monday’s Journal of the American College of Cardiology reviewed previous studies and suggested marijuana can cause some of the same cardiovascular health problems as smoking cigarettes. The review also found certain cardiovascular medications can be affected by marijuana use. 

“Our review suggests that smoking marijuana carries many of the same cardiovascular health hazards as smoking tobacco,” lead author Dr. Muthiah Vaduganathan, a cardiologist at Brigham and Women’s Hospital in Boston, said in a statement.

“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 have been hospitalized with heart failure.”

The review found certain cardiovascular medications, including statins and blood thinners, can be affected by marijuana use. Statin levels can increase in the blood when used together with marijuana as both are metabolized through a network of liver enzymes. Levels of blood thinners like warfarin can also increase when used with marijuana. Using the drugs simultaneously with marijuana can change the effectiveness or potency of the medications, causing excessive bleeding or dangerous drops in blood pressure. 

The review suggested cardiologists screen their patients for marijuana use, asking them how they ingest the drug and how often they use it. Those not taking heart medications are also advised to pay attention to how marijuana affects their heart rate. 

Heart health is also impacted differently depending on how marijuana is ingested. Smoking has the largest negative impact and carries risks similar to smoking tobacco, while edible marijuana products pose the least risk. 

“Now that we have seen marijuana use become more popular than tobacco smoking, we need more rigorous research, including randomized clinical trials, to explore the effects of marijuana on cardiovascular health,” Vaduganathan said. 

Published on Jan 21, 2020