For the retrospective analysis, the researchers used the TriNetX database, which contains electronic medical records. The study participants had no serious cardiovascular diseases at the start of the study, their cholesterol levels and blood pressure were within normal limits, they did not smoke regular cigarettes, and they did not have diabetes.
Over a 3-year follow-up period, cannabis users were found to have a fourfold increased risk of ischemic stroke, a twofold increased risk of heart failure, and a threefold increased risk of death from cardiovascular disease.
A meta-analysis involving over 75 million people used data from the United States, Canada, and India. Of the 12 studies, seven found a significant association between cannabis use and heart attack, four found no difference, and one showed a weak inverse association. However, when combining data from all studies, the researchers confirmed a 1.5-fold increased risk of heart attack in active marijuana users.
Data analysis revealed that most studies used similar methods to assess cannabis use and heart attack incidence. However, the researchers failed to account for factors such as frequency and volume of use, as well as the influence of other substances, including tobacco and illegal drugs.
Researchers have suggested that marijuana may affect the cardiovascular system in a number of ways. It can disrupt heart rhythm, increase the heart muscle's need for oxygen, and impair vascular tone and dilation, potentially leading to vascular occlusion.
One study found that the risk of heart attack increases within the first hour of using marijuana.
The study's limitations stem from the retrospective nature of the data. Scientists believe that additional research will help identify the highest-risk groups. In 2023, American cardiologists already presented data confirming a link between daily marijuana use and an increased risk of coronary heart disease.
The study's findings were published in the journal JACC Advances and will also be presented at the annual meeting of the American College of Cardiology (ACC.25). Doctors urge that cannabis use be considered when assessing cardiovascular risk, as is already done with cigarette smoking. The authors of the study believe that people should be aware of the potential risks.
