Marijuana use may increase heart complications in young, middle-aged adults

"In prior research, we identified several remarkable cases of cardiovascular complications as the reasons for hospital admission of young marijuana users," said Émilie Jouanjus, Pharm.D., Ph.D., lead author of the study and a medical faculty member at the Centre Hospitalier Universitaire de Toulouse in Toulouse, France. "This unexpected finding deserved to be further analyzed, especially given that the medicinal use of marijuana has become more prevalent and some governments are legalizing its use."

Researchers analyzed serious cardiovascular-related complications following marijuana use that was reported to the French Addictovigilance Network in 2006-10. They identified 35 cases of cardiovascular and vascular conditions related to the heart, brain and limbs.

Among their findings:

• Most of the patients were male, average age 34.3 years.
• Nearly 2 percent (35 of the 1,979) marijuana-related complications were cardiovascular complications.
• Of the 35 cases, 22 were heart-related, including 20 heart attacks; 10 were peripheral with diseases related to arteries in the limbs; and three were related to the brain's arteries.
• The percentage of reported cardiovascular complications more than tripled from 2006 to 2010.
• Nine patients, or 25.6 percent, died.

Researchers note that marijuana use and any resulting health complications are likely underreported. There are 1.2 million regular users in France, and thus potentially a large amount of complications that are not detected by the French Addictovigilance System.

"The general public thinks marijuana is harmless, but information revealing the potential health dangers of marijuana use needs to be disseminated to the public, policymakers and healthcare providers," Jouanjus said.

People with pre-existing cardiovascular weaknesses appear to be more prone to the harmful effects of marijuana.

"There is now compelling evidence on the growing risk of marijuana-associated adverse cardiovascular effects, especially in young people," Jouanjus said. "It is therefore important that doctors, including cardiologists, be aware of this, and consider marijuana use as one of the potential causes in patients with cardiovascular disorders."

Surveillance of marijuana-related reports of cardiovascular disorders should continue and more research needs to look at how marijuana use might trigger cardiovascular events, she said.