Regular recreational cannabis use may increase risk of cardiac abnormalities

Regular cannabis users at increased risk of cardiac abnormalities.

UK: People who regularly use cannabis are at increased risk of adverse changes in the left ventricular size and subclinical dysfunction compared to people who rarely or never used cannabis, suggests a recent study published in the journal JACC Cardiovascular Imaging.

"To the best of our knowledge, this is the first study to systematically report alterations in cardiac structure and function associated with recreational cannabis use using CMR, the current gold standard for cardiac chamber assessment," wrote the authors.

Cannabis is the most commonly abused illicit drug with a steadily increasing prevalence in usage and abuse over the past decade, especially among adolescents especially in the Westernized World. The effects of marijuana on the CV system are extremely worrisome and likely need more attention due to the growing legalization of cannabis for medicinal and recreational use.

The WHO has warned against the potentially harmful effects of nonmedicinal cannabis use and highlighted the need for more research assessing the link between cannabis smoking and cardiovascular disease (CVD) in adults. Previous use of recreational cannabis was not associated with such features, suggesting that any deleterious effects may not be permanent.

Mohammed Y. Khanji, Queen Mary University of London, United Kingdom, and colleagues studied the association of cannabis use with cardiac structure and function using cardiovascular magnetic resonance (CMR) parameters in the UK Biobank population study.

For the purpose, the researchers analyzed cardiovascular MRI data from people who did not have CVD and were participants in the UK Biobank population study.

• "rare/no," meaning no use or less than monthly usage of cannabis;


• "previously regular," defined as weekly or daily usage of cannabis up to 5 years before the interview; or


• "current regular," defined as weekly or daily cannabis usage within 5 years of the interview.

The study included 3407 individuals. The average age was 62 years, and 55% were women. Of the participants, 47 individuals reported being current regular cannabis users, 105 said they were previous regular users, and 3255 said they were rare or nonusers.

Read Also: Cannabis linked to severe heart attack risk among adolescents

Key findings of the study include:

• Current regular users were more likely to be younger, male, and current tobacco smokers and have greater levels of social deprivation compared with rare/never users and previous regular users.


• They were also less likely to be taking antihypertension medication.


• Regular cannabis use was associated with larger indexed left ventricular end-diastolic volume (+5.31 ml/m²), end-systolic volume (+3.3 ml/m²), and impaired global circumferential strain (−0.78) compared with rare/no cannabis use, even after adjustment for potential confounders including age, sex, body mass index, systolic blood pressure, use of cholesterol medication, diabetes, smoking, and alcohol consumption.


• After multivariable adjustment, there were no differences between left ventricular myocardial mass, ejection fraction, and stroke volume or right ventricular, left atrial, and right atrial parameters.


• Previous cannabis users had similar parameters to rare/never users.

The researchers warn --> The findings should be interpreted with caution and there is a need for further research to understand the potential pathophysiology, dose-response effects of cannabis use, and long-term implications of regular use on the cardiovascular system.

"Health care professionals and policy-makers may need to advise caution on regular recreational cannabis use until such systematic research is available," they wrote.

The study, "Association Between Recreational Cannabis Use and Cardiac Structure and Function," is published in the journal JACC Cardiovascular Imaging.

DOI: https://doi.org/10.1016/j.jcmg.2019.10.012