French study provided support for an association between marijuana use and cardiovascular complications in younger adults,
Over a 5-year period, 35 of 1,979 cannabis-related reports of serious adverse events (1.8%) received by a surveillance network in France involved cardiovascular complications, with an increase over time, according to Emilie Jouanjus, PharmD, PhD, of the Centre Hospitalier Universitaire de Toulouse, and colleagues.
Most of the events (22) were cardiac, but there were also 10 peripheral and three cerebral events; about one-quarter (25.6%) resulted in death, the researchers reported online in the Journal of the American Heart Association.
The findings are consistent with case reports of potential harm from marijuana use accumulating in the literature alongside the studies showing the benefits of cannabis for treating patients with conditions such as chronic neuropathic pain, glaucoma, multiple sclerosis, HIV, and other conditions related to chronic pain.The Study
The current data came from the French Addictovigilance Network, which collects information on serious cases of abuse of and dependence on psychoactive substances. The network relies on spontaneous reporting of events, and health professionals are legally obligated to report serious cases.
Of the 35 serious cardiovascular complications reported in users of cannabis from 2006 to 2010, most (85.7%) occurred in men. The average age of the patients was 34.
Nine had a personal history of cardiovascular disease and seven had a familial history. More than half (60%) also smoked tobacco.
The majority of the complications were cardiac, with 20 acute coronary syndromes and two heart rate disorders. Ten of the complications involved the peripheral vasculature, including lower limb or juvenile arteriopathies and Buerger-like diseases, and three involved the cerebral vasculature, including one case each of acute cerebral angiopathy, transient cortical blindness, and spasm of cerebral artery.
Eighteen of the patients were hospitalized and nine died; none of the deaths occurred in patients who were hospitalized.
The main shortcoming of the study, according to the authors, was the under-reporting of events, which resulted in a low number of events and the inability to determine whether the observed complications were actually related to cannabis use.
Risk in the Context of Expanding Use
In an accompanying editorial in the journal, Shereif Rezkalla, MD, of the Marshfield Clinic in Wisconsin, and Robert Kloner, MD, PhD, of the University of Southern California in Los Angeles, pointed out that several countries and 20 U.S. states and the District of Columbia have legalized the use of marijuana for medicinal purpose. In addition, Colorado and Washington have legalized the recreational use of marijuana, with other states preparing similar measures.
The potential for more widespread legalization raises the issue of safety, according to Rezkalla and Kloner, who recently published a review of reports of adverse vascular effects of marijuana. Events tied to marijuana use included myocardial infarction, sudden cardiac death, cardiomyopathy, stroke, transient ischemic attack, and cannabis arteritis.
While the concomitant use of other products, such as tobacco and alcohol, may have contributed to some of these events,” they wrote, “approximately half of the patients who presented with cardiac events had a record of exposure only to marijuana
Financial support for the study was provided by the French InterMinisterial Mission for the Fight Against Drugs and Addiction (MILDT, Mission interministérielle de lutte contre les drogues et toxicomanies) and the French drug agency (ANSM, Agence Nationale de Sécurité des Médicaments).
The study authors and the editorialists disclosed no relevant relationships with industry.