This week there has been a flurry of discussion about cannabis’ harmful effects on the heart. I have received numerous anxiety-ridden emails from colleagues, patients, and my mother (she’s not on cannabis, go figure). This all stems from a recently published scientific paper in the Journal of the American Heart Association. (1)
More importantly, and perhaps more politically, this study was singled out for an article in the New York Times (2), leading to an otherwise important, but no more important than the many studies that came before, study triggering wide-spread panic.
There have been a number of retrospective registry based studies over the years that have demonstrated an association between cannabis use and myocardial infarction (heart attack), congestive heart failure (CHF), atrial fibrillation, and stroke. Relative risk has been demonstrated at between 20-40% higher than non-users. To that extent, the AHA study really doesn’t demonstrate anything new.
These studies, as well as the AHA study, by the nature of their design cannot be conclusive. They are, however, concerning and worthy of further study.
Moreover, there are similar or better designed studies that show the opposite. (3) For example, the widely touted risk of atrial fibrillation seems to have been debunked. (4)
So what do we do in response to this and other studies?
We need to put these studies in proper perspective. This entails understanding the methodology and utility of the study and the implications of relative risk for both our patient population and the general consumer.
From a medical perspective, all medication confers risk as well as potential benefit. Medications like opioids and benzodiazepines carry risk of respiratory suppression and addiction. Amiodarone and Warfarin are crucial cardiac medications that can have dire adverse consequences if misused, and possibly even if used correctly. Clozapine is an anti-psychotic that gets used when all else has failed because it can cause fatal bone marrow suppression. We use these medications despite their being dangerous – but we use them carefully, with due consideration, at the minimum necessary dose, and with a properly informed and consenting patient.
As I always maintain, cannabis is no different. It is our job, as medical practitioners, to evaluate the individual and determine that the benefit outweighs the risk for that person. This includes careful history taking and laboratory testing where appropriate. Conferring with our Cardiology colleagues is also a good idea. As in all other fields of Medicine, we must properly inform the patient of those risks so that they can make decisions about their care.
What Are the Implications for the General Population?
From a public health point of view, it is certainly possible that these risks may become more prevalent, but data show that the percentage of US cannabis users is not rising despite legalization. (5) On the other hand, there is substantial increase in cannabis use in the older segment of the US population (6), which of course, has the highest burden of disease both that would respond to cannabinoid treatment and that might complicate cannabis use.
The key, which is presently not being undertaken in any systematic fashion, is to properly educate consumers. For those who have cannabinoid-treatable illnesses it is imperative that we refer those patients to competent, caring, and responsible Cannabinoid Specialists to ensure that they are treated and followed carefully. Patients should not be encouraged to self-medicate – yet that is exactly what is going on in the media and cannabis marketing.
Those who are, in fact, using cannabis truly for recreational purposes still need to be evaluated for and advised about their risk. We must meet them where we usually do, in their primary care office. To that extent, we must educate our front-line clinicians about both the positives and negatives of cannabis use, and also work diligently to destigmatize the use of recreational substances so that patient feel safe to have a frank discussion with their practitioners. (7)
So What Now?
Frankly, this study doesn’t change much. Our patients have the same risk today as they did yesterday. If you’re a cannabinoid specialist, be sure you’re up to date on the risks as well as the benefits of cannabis. If you’re a member of ACS, you have a number of tools at your disposal to help (Clinical Reference Library, Cannabis and Cannabinoid Research journal, Handbook of Cannabinoid Therapeutics, and monthly live mentoring discussions). If you’re not yet a member, please join.
If you’re a cannabis patient or a cannabis user, please don’t freak out. If you have questions or reasons to worry about your heart health, contact your Cannabinoid Specialist or PCP. If they don’t know the answers, please get in touch with us and we’ll be happy to answer your questions, and to provide your clinicians with an education on this topic.
References:
- Jeffers, A. M., Glantz, S., Byers, A. L., & Keyhani, S. (2024). Association of Cannabis Use With Cardiovascular Outcomes Among US Adults. Journal of the American Heart Association, e030178. https://doi.org/10.1161/JAHA.123.030178 https://www.ahajournals.org/doi/10.1161/JAHA.123.030178
- https://www.nytimes.com/2024/02/28/health/marijuana-heart-attack-stroke.html?unlocked_article_code=1.ZE0.LQdS.TQvXP2lZaf5f&smid=url-share
- Corroon, J., Grant, I., Allison, M. A., & Bradley, R. (2023). Associations Between Monthly Cannabis Use and Myocardial Infarction in Middle-Aged Adults: NHANES 2009 to 2018. The American Journal of Cardiology, 204, 226–233. https://doi.org/10.1016/J.AMJCARD.2023.07.065
- Teraoka, J. T., Tang, J. J., Dellling, F. N., Vittinghoff, E., & Marcus, G. M. (2023). Cannabis Use and Incident Atrial Fibrillation in a Longitudinal Cohort. Heart Rhythm. https://doi.org/10.1016/j.hrthm.2023.12.008
- Substance Abuse and Mental Health Services Administration, 2022 National Survey on Drug Use and Health Annual National Report, https://www.samhsa.gov/data/report/2022-nsduh-annual-national-report
- Abuhasira, R., Schleider, L. B. L., Mechoulam, R., & Novack, V. (2018). Epidemiological characteristics, safety and efficacy of medical cannabis in the elderly. European Journal of Internal Medicine, 49, 44–50. https://doi.org/10.1016/j.ejim.2018.01.019
- King, D. D., Gill, C. J., Cadieux, C. S., & Singh, N. (2024). The role of stigma in cannabis use disclosure: an exploratory study. Harm Reduction Journal, 21(1), 21. https://doi.org/10.1186/s12954-024-00929-8