Abacavir (found in Ziagen, Epzicomand Trizivir) is associated with a quadrupled risk of a heart attack in HIV-positive patients using the drug, according to the authors of a study published in the September 12 issue of AIDS. These data are an expansion of results from the Strategies for Management of Anti-Retroviral Therapy (SMART) study presented earlier this month at the XVII International AIDS Conference in Mexico City.

In short, researchers analyzed the risk of cardiovascular disease among patients using various antiretroviral (ARV) therapies in SMART, a 5,500-patient clinical trial evaluating differences between those on and off HIV treatment. The analysis was conducted after the 33,000-patient Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study, released in February, documented a 90 percent increase in the risk of a heart attack among individuals using abacavir.

As with the D:A:D study, the increased risk in SMART was most pronounced in people with a number of other cardiovascular disease risk factors, such as smoking, diabetes and a family history of heart problems. Though a mechanism to explain the association between heart attack risk and abacavir has not yet been officially determined and an analysis of multiple abacavir studies by the drug’s maker, GlaxoSmithKline, did not find an increased heart attack risk, people with a number of cardiovascular disease risk factors who are taking abacavir may wish to discuss these data with their health care provider.