Conflicting Study Results Are Presented on Cardiovascular Risks

Studies presented in February at the 10th annual Conference on Retroviruses and Opportunistic Infections on cardiovascular complications among HIV-positive people were a mixed bag, with contradictory research showing that antiretroviral drugs both boost and lower cardiac risks. Data from a study by researchers in Copenhagen showed that taking anti-HIV medications significantly raises a person's risk of suffering a heart attack, boosting the likelihood by 26% each year. The findings of a study by Bristol-Myers Squibb were even grimmer, showing that protease inhibitors double cardiac risk. Troubling research presented at the conference included data from an ultrasound study conducted by University of California researchers showing that patients on antiretroviral therapy had an average arterial buildup of 0.1mm, much higher than the buildup typically seen in elderly men who have already suffered heart attacks. Studies presented at other conferences or published in medical journals confirm a link between anti-HIV drugs and cardiovascular problems, including a study presented at the 28th International Stroke Conference showing that protease inhibitors cause a thickening of the carotid arteries, which suggests a boost in the risk for strokes. Research conducted at the University of Kentucky College of Medicine suggests that protease inhibitors can lead to arterial blockages and artery damage even if blood-based lipid levels remain low. But a large research study conducted on HIV-related cardiac risk flatly contradicts the mounting evidence linking anti-HIV drugs with heart problems. The study, published in the February 20 edition of The New England Journal of Medicine, included an analysis of the medical records of nearly 37,000 HIV-positive patients who received care at Veterans Affairs facilities from 1993 to 2001. The researchers found that combination therapy does not cause premature heart attacks or strokes. Instead, the numbers of patients treated for the conditions actually decreased after protease inhibitor'based cocktails became available. AIDS experts, led by Wafaa El-Sadr, MD, of New York City's Harlem Hospital, also are unsure about the link between anti-HIV medications and cardiac risks. A study they presented at the retroviruses conference showed that HIV-positive people, whether they take antiretrovirals or not, are typically more obese, smoke more, and are more likely to have hypertension or diabetes than average Americans. All of these conditions are linked with the development of cardiovascular problems. So what should one make of the conflicting data? It is still too soon to tell precisely what is happening and why, according to Judith Currier, MD, an associate professor of medicine at the University of California, Los Angeles. Speaking at the 40th annual meeting of the Infectious Diseases Society of America in October, Currier called for continuing research to shed more light on the issue.