More than two million adults with heart conditions report that they have used or are currently using marijuana, according to a new study.
Observational studies have linked marijuana use to a range of cardiovascular risks, including stroke, arrhythmia and diseases that make it hard for the heart muscle to pump properly, said the researchers.
"Marijuana use, both recreational and medical, is increasing nationally yet many of its cardiovascular effects remain poorly understood," said lead author Ersilia M DeFilippis from Columbia University in the US.
"In our National Health and Nutrition Examination Survey (NHANES) query, we estimated that two million adults with marijuana use had cardiovascular disease in 2015-2016. Since that time, additional states have passed legislature related to marijuana so its use may have increased even further," DeFilippis added.
"Notably, many of our cardiology patients are on medications that can interact with marijuana in unpredictable ways depending on the formulation. This highlights that we need more data so that we can better counsel providers as well as patients," DeFilippis said.
For the findings, published in the journal Journal of the American College of Cardiology, researchers, including one of the Indian-origin, conducted a query of data from NHANES to estimate marijuana use among US patients with cardiovascular disease.
They estimated that two million (2.3 per cent) of the 89.6 million adults who reported marijuana use had cardiovascular disease.
According to the study, the researchers outline the ways that the components and compounds in marijuana may affect the heart and other tissue at a molecular level and the drug interactions that marijuana can have with drugs that are commonly given to cardiology patients.
They also describe observational studies that suggest a connection between marijuana and heart conditions, including: Smoking-related cardiotoxicity: Many of the same cardiotoxic chemicals found in cigarettes are also found in marijuana smoke.
Coronary artery disease: Cannabis inhalation can increase heart rate and blood pressure and may be a trigger of a heart attack.
Arrhythmias: Marijuana use has been associated with abnormal heart rhythms, including atrial fibrillation.
Cerebrovascular disease: Surveys have found that marijuana smokers were three times more likely to experience a cerebrovascular event, such as a stroke.
"This was eye-opening for us. We're seeing an accelerating use of marijuana and now, for the first time, marijuana users are exceeding cigarette smokers in the US. said Indian-origin researcher and study author Muthiah Vaduganathan from Brigham and Women's Hospital in the US.