The aorta is a major blood vessel that carries blood to the organs of the body. Aortic dissection occurs when the inner lining of the aorta, which has three layers, tears and blood rushes in separating the walls of the aorta, explained Priscilla Hsue, MD, UCSF cardiology fellow at San Francisco General Hospital Medical Center (SFGHMC) and lead author of the study. This disruption of the integrity of the three layers may lead to aortic rupture and death, explained the researchers.
“Aortic dissection is a potentially fatal condition and is not often the cause of chest pain. Therefore, it’s important for health care providers to be aware of the potential for aortic dissection, so they can ask patients who present with chest pain about cocaine use,” said Hsue. “Early recognition is crucial because, if left untreated, the death rate from aortic dissection is 35% at 24 hours, 50% at 48 hours and 80% by two weeks after the rupture.”
“This condition usually occurs in older individuals with high blood pressure, and cocaine use is not a commonly recognized risk factor for aortic dissection,” said Hsue. “We initiated this study when we noted cases of aortic dissection in younger individuals who did not have the usual risk factors, but admitted to habitual cocaine use.”
Among the 38 cases of aortic dissection studied at SFGHMC, 14 (37%) were related to recent cocaine use, according to the study, which appears in the April issue of Circulation. Patients with cocaine-related dissection were more likely to be African-American and were younger (average age 41) compared to other aortic dissection patients (average age 59). For the 13 analyzed cases in which cocaine was smoked and the singular case in which it was snorted, the average onset of chest pain after use was 12 hours (ranging from 0 to 24 hours), according to the researchers.
Type A dissections involve the ascending aorta (the portion closest to the heart) and usually require surgery. Type B dissections involve lower sections of the aorta and are sometimes treated with blood-pressure-lowering medications alone. The two groups (cocaine users and non-users) did not differ with respect to type of dissection; however, cocaine users were more likely to undergo emergency surgery. Twenty nine percent of the cocaine users died as a result of aortic dissection as compared to seventeen percent of the non-cocaine users.
Co-investigators on the study include: Ann F. Bolger, MD, UCSF associate professor of cardiology at SFGHMC; Neil L. Benowitz, MD, UCSF professor of pharmacy at SFGHMC; David D. Waters, MD, UCSF professor of cardiology at SFGHMC; and Cynthia Salinas, UCSF medical student.
Hsue’s research is funded by a grant from the Doris Duke Charitable Foundation. The Doris Duke Charitable foundation medical research program seeks to further the prevention and cure of disease by supporting clinical research, in four disease areas: cancer, AIDS, cardiovascular diseases, and sickle cell anemia and blood disorders.