Amitoj Singh MD, Mark Fegley, M.D., Yugandhar Manda, M.D., Sudip Nanda, M.D., and Jamshid Shirani, M.D.
As reported November 13, 2016 on cnn.com, researchers presented data at a recent American Heart Association meeting. Their findings show a link between marijuana use and stress cardiomyopathy in younger men.
Data from the Nationwide Inpatient Sample identified 33,343 people who were hospitalized with stress cardiomyopathy between 2003-2011 in the United States. Of those, 210 (less than one percent) were also identified as marijuana users. Younger marijuana users were twice as likely as non-users to experience stress cardiomyopathy. This was a retrospective observational study. Marijuana use was identified by self-reporting of marijuana use or urine testing and was compared to patients who did not report use.
The researchers found that marijuana users were almost twice as likely to develop stress cardiomyopathy compared to non-users, even after controlling for other cardiovascular risk factors. Compared with non-users, researchers found that marijuana users were more likely to be younger, male and had fewer cardiovascular risk factors, including less high blood pressure, diabetes and high cholesterol.
However, despite being younger and with fewer cardiovascular risk factors than non-users, during stress cardiomyopathy the marijuana users were significantly more likely to go into cardiac arrest (2.4 percent vs. 0.8 percent) and to require an implanted defibrillator to detect and correct dangerously abnormal heart rhythms (2.4 percent vs. 0.6 percent).
Marijuana users were more likely than non-users to have a history of depression (32.9 percent vs. 14.5 percent), psychosis (11.9 percent vs. 3.8 percent), anxiety disorder (28.4 percent vs. 16.2 percent), alcoholism (13.3 percent vs. 2.8 percent), tobacco use (73.3 percent vs. 28.6 percent) and multiple substance abuse (11.4 percent vs. 0.3 percent). Because some of these can increase the risk of stress cardiomyopathy, the researchers adjusted for known risk factors to investigate the association between marijuana use and stress cardiomyopathy.
The study has many limitations. Because this was a retrospective study, the researchers could not determine how frequently the marijuana users were using marijuana or how much they ingested. In addition, there is no history of the timeframe between the use of marijuana and occurrence of stress cardiomyopathy. History of marijuana use was only as good as the documentation in the charts. Results showed these subjects had higher rates of alcoholism and multiple substance abuse. From this it is not known the extent of alcohol abuse or which other substances were being used, which could contribute to developing stress cardiomyopathy.
As with almost all observational studies it does not prove cause and effect; therefore, it cannot be said that marijuana is or is not a direct cause of stress cardiomyopathy. With statistical analysis it shows there is a relationship associated with marijuana use and stress cardiomyopathy. But it is with uncertainty what the relationship may be. In addition, because the database the researchers used reports regional but not state-by-state statistics, the researchers could not analyze whether possibly marijuana-related heart problems are increasing where use is legal.