Cocaine users in their mid-40s had more than four times the risk of coronary artery aneurysms as non-users, researchers report in today’s Circulation: Journal of the American Heart Association.
Researchers said this study is the first to document an association between cocaine use and coronary aneurysms, weakened areas that balloon out in the coronary artery walls. These findings may also help explain why cocaine users have a higher risk of heart attack.
“We found a significantly higher percentage of aneurysms in patients who had used cocaine than in a group of patients of similar age who did not,” said the study’s senior author, Timothy D. Henry, M.D., director of research at the Minneapolis Heart Institute Foundation at Abbott Northwestern Hospital, and an associate professor at the University of Minnesota.
Researchers examined the records of 191 men and women. They included 112 cocaine users who underwent angiography for known or suspected heart problems during a 10-year period and 79 age-matched controls who also underwent angiography. Henry and his colleagues identified definite or probable aneurysms in the coronary arteries of 30.4 percent of the cocaine users compared to only 7.6 percent of the non-user controls. The average age of the cocaine users was 43.7 years and that of the non-users was 45.6 years, an insignificant difference. Males made up 80 percent of the cocaine group compared to 61 percent of the nonuser group, a statistically significant difference. About 95 percent of the cocaine users smoked, compared to 71 percent of the control group.
The same three cardiologists read the angiogram of each patient to assess the presence or absence of coronary artery aneurysms. They classified patients as having a definite coronary artery aneurysm if all three readers agreed an aneurysm was present. An aneurysm was deemed “probable” if two of the readers agreed. In the cocaine group, 24 patients had definite coronary artery aneurysms and 10 had probable coronary artery aneurysms.
Among all study participants, a previous heart attack and cocaine use were the strongest predictors that a patient would have an aneurysm. Previous heart attack was common in both groups – 45 percent of cocaine users and 38 percent of control patients.
“The extremely high prevalence of coronary artery aneurysms in cocaine users is striking compared with the control group,” Henry said. It is also much higher than the rate of coronary artery aneurysms found in previous studies of patients undergoing angiography, which ranged from 0.2 to 5.3 percent.
About 50 percent of coronary artery aneurysms are related to the presence of atherosclerosis. Those aneurysms, located in the arteries that carry blood to the heart, rarely burst, and thus do not carry the same direct risk of death from a rupture as aneurysms in the brain and those in the aorta, the large artery that carries blood away from the heart. But at least in cocaine users, coronary artery aneurysms may contribute to death in another way — by setting up a person for a heart attack.
“It looks as if cocaine predisposes to coronary artery aneurysms, and then the aneurysms themselves may predispose to heart attacks,” Henry said.
He and his colleagues suggest two possible ways that cocaine might weaken the artery wall and lead to an aneurysm: The drug can cause sharp spikes in blood pressure and it can damage the cells that line the inner walls of the heart’s arteries.
He speculated that once an aneurysm forms, blood may flow through it in a way that facilitates blood clots to form, which, in turn, can block the flow of blood and cause a heart attack.
In 2001, 27.7 million Americans age 12 and older (12 percent of this age group) had used cocaine at least once in their lives and almost 1.7 million had used the drug in the previous month, according to the Substance Abuse and Mental Health Services Administration. Based on medical records, the researchers were able to reliably document the frequency of cocaine use in 61 of the drug users. They found that 66 percent of those patients reported using the drug at least once a week.
“This study documents that cocaine predisposes you to coronary aneurysms,” Henry said. “It’s another reason to tell people how dangerous cocaine is.”
Co-authors are Aaron Satran, M.D.; Bradley A. Bart, M.D.; Christopher R. Henry, B.S.; M. Bilal Murad, M.D.; Sumaiya Talukdar, B.S.; and Daniel Satran, M.D.