There's a lot of confusing information out there about the risk of heart disease in people who are HIV-positive and the role that antiretroviral meds play in increasing this risk. The first class of meds to be identified as increasing cardiovascular risk was protease inhibitors. But now two drugs not in that class, abacavir (Ziagen) and didanosine (Videx)'both of which are nucleoside analogs and had not been considered to have any bad effects on the heart'have been associated with an increased heart attack risk in patients of 90% and 49%, respectively.
Previously, researchers had shown that HIV itself is associated with a twofold increase in heart attack risk. Furthermore, data from the Strategies for Management of Antiretroviral Therapy study, in which patients' treatment was stopped, found that those who halted meds had more heart disease. This unexpected finding caused the investigators to stop the study and put everyone back on their regimens. So what gives? Are these meds helpful or not?
Another group of investigators tried to answer this question by looking at markers for early heart disease. These markers'like blood flow through the arteries in the neck and calcium deposits in the arteries of the heart'would hint at early heart disease and could be studied to look at risks of heart disease from many causes. In one study (ACTG 5078) researchers found that none of the anti-HIV meds, including protease inhibitors, caused early heart disease. In fact, in another of these studies (ACTG 5152), where patients were started on all kinds of anti-HIV meds, the markers for early heart disease improved in virtually everyone after starting on meds. Even though this study lasted only six months, the researchers found that not being on an antiretroviral regimen caused more heart disease than the anti-HIV meds themselves.
In a more recent study, published in the journal AIDS, researchers followed two large groups of HIV-negative and HIV-positive patients. Some of the HIVers were on meds, and some were not. In the first group, which consisted only of men, investigators found that calcium buildup in the arteries of the heart was slightly greater in those who were on treatment but that this group had less buildup than the HIV-negative men. The women's group revealed something more interesting'the only significant risk for these calcium deposits in women was a T-cell count lower than 200. Their risk was not affected by what kind of anti-HIV meds they were on!
What all these studies also showed was that the 'traditional risk factors' for heart disease'like smoking, elevated blood sugar, elevated cholesterol, and lack of exercise'proved to be the greatest risks for developing heart disease, not what kind of meds a patient was on. So doing things like treating elevated cholesterol and diabetes in conjunction with exercising more and improving diet will help prevent HIV-positive patients from getting heart disease. And most important, treating one's HIV disease and increasing one's T-cell count is always good for the heart.
Urbina is an HIV specialist and the medical director of HIV education and training at St. Vincent's Comprehensive HIV Center as well as an associate professor of medicine and an associate professor of clinical public health at New York Medical College.
