CHICAGO – Patients who reported using marijuana prior to experiencing an acute MI had significantly lower in-hospital mortality and were less likely to have cardiogenic shock or require an intra-aortic balloon pump than marijuana nonusers with an MI in an eight-state hospital records study, Dr. Cecelia P. Johnson-Sasso reported at the annual meeting of the American College of Cardiology.
“If this observation is confirmed in independent studies, further investigation into the possible therapeutic benefit of cannabinoid receptor agonists in acute MI may be warranted,” declared Dr. Johnson-Sasso of the University of Colorado Denver.
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She and her coinvestigators obtained hospital records with identity information removed for more than 3 million patients admitted for acute MI during 1994-2013 in eight states: California, Colorado, New Hampshire, New Jersey, New York, Texas, Vermont, and West Virginia.
After excluding concomitant users of cocaine, methamphetamine, or alcohol due to the potential for confounding cardiotoxic effects; MI patients under age 19 because of the likelihood of congenital heart disease; and patients over age 70 because only 0.01% of them admitted to marijuana use, the investigators were left with a study population of 3,854 marijuana users and 1.27 million MI patients who hadn’t used marijuana.
In a multivariate regression analysis adjusted for potential confounders including baseline comorbid conditions, patient demographics, and payer status, the marijuana users prior to MI had a 17% reduction in in-hospital mortality, were 20% less likely to undergo intra-aortic balloon pump placement, and had a 26% reduction in shock. On the other hand, they were also 19% more likely than marijuana nonusers to be placed on mechanical ventilation. And even though they were equally likely to undergo diagnostic coronary angiography, they were 28% less likely than marijuana nonusers to undergo percutaneous coronary intervention. All of these differences were statistically significant and clinically meaningful.
She was quick to note the limitations of her study: No data were available on readmissions or late mortality, and it’s highly likely that marijuana use by patients with acute MI was significantly underreported during the study period, which was largely before the legalization movement took off.
With state marijuana laws rapidly changing and the legal pot industry becoming a big business, the lack of research into the health consequences of marijuana by disinterested parties has become glaringly obvious, according to Dr. Johnson-Sasso. Cannabinoid receptors are found not only in the brain, but in cardiac muscle, the kidney, liver, vascular and visceral muscle, aorta, bladder, and immune cells.
She reported having no financial conflicts of interest regarding this study.