Cocaine users face a newly discovered and possibly fatal risk: coronary aneurysms, a ballooning of the walls of coronary arteries. The condition increases the chance of suffering a heart attack, even years after users stop the drug, researchers in Minnesota are reporting.
In an angiogram, the white arrows point to ballooning in the right coronary artery of a 49-year-old man who had used cocaine.
The risk of developing an aneurysm was four times as high among cocaine users in their mid-40's as among nonusers in the same age group, according to the study, reported yesterday in the journal Circulation, which is published by the American Heart Association.
Aneurysms occurred in 30.4 percent of cocaine users in the study compared with 7.6 percent of non-users.
Precisely how much cocaine is needed to produce the aneurysms is not known, but the frequency of use was clearly linked to development of aneurysms, said Dr. Timothy D. Henry, a co-author of the study.
"The risk was definitely more common in people who used cocaine at least once a week," said Dr. Henry, who directs research at the Minneapolis Heart Institute Foundation at Abbott Northwestern Hospital.
The aneurysms can be prevented by avoiding cocaine, but no specific treatment is available once they develop, Dr. Henry said, adding that he hoped his team's findings would serve as a warning.
In 2003, 34.9 million Americans ages 12 and older reported having used cocaine at least once during their lifetimes and about 2.3 million reported having used the drug in the previous month, according to the Substance Abuse and Mental Health Services Administration.
Cocaine is known to increase the risk of heart attacks within hours of its use. But because coronary aneurysms are uncommon and generally take years to form, a link to cocaine had not been suspected.
Dr. Henry cited the case of a prominent businessman who asked for a second opinion about coronary angiograms, X-rays taken when the man suffered a heart attack at 38. The angiograms showed multiple aneurysms of the coronary arteries that nourish the heart.
The man did not have atherosclerosis, which accounts for about half of coronary aneurysms, or any of the rarer conditions associated with aneurysms, like syphilis, trauma and lupus and other connective tissue disorders. So Dr. Henry asked if the man had ever used cocaine.
"How did you know I did?" the man responded.
The man said he had used cocaine for two years when he was in his 20's, but not since.
Dr. Henry said he began wondering about the link five years ago when he saw aneurysms in angiograms of three heavy cocaine users. So he started a systematic search to determine how often the aneurysms occurred among the users.
The researchers examined the records of 191 men and women whose average age was in the early 40's. The patients included 112 cocaine users who had angiography for known or suspected heart problems during a 10-year period and 79 nonusers of similar age who also had the procedure. An angiogram involves inserting a tube in an artery in the upper leg or arm, threading it into the heart, and injecting a chemical dye to outline the arteries on X-rays.
Three cardiologists examined the angiogram of each patient in the study to determine the presence or absence of coronary artery aneurysms. If all three doctors agreed that a coronary aneurysm was present, they classified it as definite. If two doctors concurred, they considered the aneurysm probable. In the cocaine user group, 24 patients had definite coronary artery aneurysms and 10 had probable ones.
Using information that the patients had previously told their doctors, the researchers calculated the frequency of cocaine use in 61 of the drug users and found that 66 percent reported using the drug at least once a week.
Aneurysms can occur in any artery. They are particularly frequent in the brain and in the aorta, the main artery that carries blood from the heart to the rest of the body, often ripping open to cause strokes and sudden death.
Aneurysms in the coronary arteries rarely burst and pose a less direct risk of death than do brain aneurysms or aortic aneurysms. But the study showed that coronary artery aneurysms might kill by setting up cocaine users for a heart attack.
Dr. Henry's team theorized that cocaine might weaken the artery wall and lead to an aneurysm by causing sharp spikes in blood pressure and damaging cells in the inner walls of the heart's arteries. Once an aneurysm forms, blood may flow through it in a way that makes it easier for blood clots to form. Those, in turn, can then stop the flow of blood and cause a heart attack.
Dr. Henry said he hoped to collaborate with other cardiologists to further confirm the findings by conducting similar studies and using non-invasive techniques like echocardiography and rapid CT scans to determine when and how often the aneurysms form.
Meanwhile, a number of other doctors who have learned of the Minnesota team's findings have told Dr. Henry that they have found coronary aneurysms among cocaine users.
