The Highs and Lows of Cannabis in Cardiac Rehabilitation

As cannabis becomes legalized in more places—and as its use as an alternative medicine continue to spark interest—it is unsurprising that cardiac rehabilitation patients are interested in using it.

Dr. Paul Oh, the medical director of the Cardiovascular Prevention and Rehabilitation Program at the Toronto Rehabilitation Institute, says those working in cardiac rehabilitation should be aware of the role cannabis can play in their patient’s lives and how it might affect their medical issues.

“There should be greater awareness,” he said. “Many people in rehabilitation programs, whether they admit it or not, are going to be users, so we need to understand what are the potential problems. Cannabis products should be on our list of things to think about.”

Oh, who is hosting an AACVPR webinar on the topic on Feb. 25, said there is a lot of gray area around the implications of using cannabis.

Because it was illegal in many countries, including the U.S. and Canada, significant scientific studies haven’t been done on its medical uses. In Canada, recreational marijuana was legalized in 2018. In the U.S., it’s still illegal on a federal level, however many states have legalized medical or recreational marijuana—sometimes both.

Some studies show cannabis is effective in treating pain. Oh said as agencies move away from using opioids as a pain management tool, cannabis—specifically cannabidiol, or CBD—has become a natural remedy. In his own experience, he’s seen cardiac rehabilitation patients who suffer from other ailments, like diabetes, use the substance for pain or sleep management.

However, Oh said those with heart conditions should be aware of how CBD interacts with their other medications.

“CBD is neutral to the heart. But the interesting thing with CBD is that it may interfere with some of the medications that people are taking for their hearts,” he said. “There are some potential drug interactions with CBD and common drugs like calcium channel blockers or statins. These are common things people take.”

As for THC—the psychoactive part of cannabis that is what gets people “high”— that can have negative effects on the heart as well. Research shows THC can increase heart rate up quickly and excessively —especially if the patient is smoking it.

For some patients, this may precipitate cardiac ischemia and can cause a heart attack pattern similar to what physicians see with the “Broken Heart Syndrome,” (or Takotsubo cardiomyopathy) which is typically seen in older women who are under severe emotional distress. Oh said hospitals are seeing more young men come to the emergency room with these symptoms, and typically, they smoked marijuana.

“Smoking marijuana brings a lot of THC into your body very quickly,” he said. “That is where we point to some of the concerns about the heart.”

For those with compromised cardiac systems, this surge in heart rate can cause undue stress, impair blood flow, and cause rhythm problems.

Oh also cautioned against cardiac rehabilitation patients smoking marijuana. While some argue it’s not as harmful as smoking cigarettes, Oh said medical professionals should caution their patients to not smoke anything.

“Supporters of the cannabis movement say there’s nothing wrong with smoking a plant—that it’s good for you,” he said. “But I think we would feel, as medical practitioners, that smoking is not a good route to put anything in your body due to the hundreds of harmful chemicals that are formed during combustion.”

While there are some concerns about marijuana, Oh said there’s not enough research yet to determine its effects on both a positive and negative level. But as use increases, he said physicians need to treat it like any other potential risk factor when dealing with cardiac rehabilitation patients.

“I would consider it much like we consider alcohol,” he said. “It’s better for us to know and to ask specifically what kind of cannabis they are using, and that’s where we need more health care awareness. We need to have an appreciation for it and the fact people are using it, because it’s complex.”

Oh’s webinar “The Highs and Lows of Cannabis in the Rehab Setting” is on Tuesday, Feb. 25 at 1 p.m. ET. To register, please visit our website.

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