Aortic dissection occurs when the lining of the aorta – the major blood vessel that carries blood from the heart – tears, exposing the second layer. Cocaine use causes an extraordinary outpouring of stress hormones that can cause blood pressure to quickly rise. This may tear the lining of the vessel, called the intima.
“As the vessel pulses, the inner lining starts to peel away. This is a very dangerous process that can move rapidly once it is started,” says researcher Ann F. Bolger, M.D., associate professor of medicine at the University of California at San Francisco. The dissection may block blood from reaching critical organs, or even cause the aorta to rupture.
“This is such a lethal condition that patients may die if they don’t make it to the emergency room quickly,” she says. “Nurses and physicians must be suspicious and ask about cocaine use and exposure. Patients aren’t always anxious to mention drug use, but a history of cocaine use should raise a flag.”
An early diagnosis is imperative. Within the first 24 hours of a dissection of the aorta close to the heart, 25 percent of patients die. By 48 hours, half die, Bolger says.
The symptoms of aortic dissection usually start with chest and back pain and often are mistaken for a heart attack. However, if the person is young and the tests for heart attack are negative, then the physician must go further to make the diagnosis, Bolger notes.
Aortic dissection usually occurs in older individuals who have high blood pressure and may also occur as a result of a congenital disorder called Marfan syndrome.
The study was undertaken when researchers noticed cases of aortic dissection in younger individuals who did not have the usual risk factors, but admitted to habitual crack cocaine use, says lead researcher, Priscilla Y. Hsue, M.D., a cardiology fellow. Cocaine use is not a commonly recognized risk factor for aortic dissection.
Hsue and other researchers reviewed hospital charts of individuals diagnosed with aortic dissection at San Francisco General Hospital from 1981 to 2001. Thirty-eight cases were noted and 14 (37 percent) patients had used cocaine. Crack cocaine was smoked in 13 cases and powdered cocaine was snorted in the other. Crack is a form of smokable cocaine derived from powdered cocaine. Smoking allows extremely high doses of cocaine to reach the brain very quickly and brings an intense and immediate high. Powdered cocaine is inhaled through the nose where it is absorbed into the bloodstream through the nasal tissues or injected directly into the bloodstream.
The cocaine users were a median age of 42, which is 18 years younger than non-cocaine users who had aortic dissection. The average time of onset of chest pain after cocaine use was 12 hours. In the group of cocaine users, there was a higher number of African Americans. There were no significant differences in the incidence of hypertension among users and non-users or whether they were taking medications for high blood pressure.
Twenty-nine percent of those who had used cocaine died as a result of aortic dissection, while 17 percent of individuals who had not used cocaine died of the condition, Hsue notes.
Type A dissections involve the ascending aorta and usually require surgery. Type B dissections are sometimes treated with blood pressure-lowering medication alone. Although the two groups did not differ with respect to type of dissection, cocaine users were more likely to undergo emergency surgery compared to aortic dissection patients without cocaine use. Other study co-authors are: Cynthia Salinas and David Waters, M.D.
CONTACT:
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Abstract 3041 (Poster)
(This news release contains updated data)
NR01-1354 (SS2001/Hsue)