HIV Drugs May Raise Heart Attack Risk

(Page 2)

In the new, prospective study, a group of European and American researchers analyzed data on more than 23,000 HIV-infected patients treated for an average of 4.5 years at 188 clinics in 21 countries.

Nearly all -- 93.6 percent -- of the patients received some form of antiretroviral therapy.

According to the researchers, 345 of the patients experienced either a fatal or non-fatal heart attack during the course of the study.

Breaking it down by treatment type, Lundgren's group found that the use of protease inhibitors boosted a patient's risk for heart attack by 16 percent for every year they were on the drugs.

"This association was partly explained by how these drugs adversely affect cholesterol levels," Lundgren noted.

Without more research, the small but significant hike in risk remains tough to explain, Lundgren said. However, he noted that "there is emerging evidence to suggest that protease inhibitors adversely affect the activity of cells (called macrophages) involved in the atherosclerotic process in the arterial wall."

Another major class of HIV-suppressing drugs, called non-nucleoside reverse-transcriptase inhibitors, had no effect on heart attack risk, the study found.

None of this means that HIV-positive individuals should forego HAART, which has kept thousands of infected people alive and relatively healthy since the drugs were introduced more than a decade ago.

"All they are saying here is that the increase in (heart attack) risk is there, and that doctors had better look out for it," said Rowena Johnston, vice president of research at the Foundation for AIDS Research (amfAR), based in New York City. "Doctors have to be vigilant; it adds a new level of complication to the person's care," she said.

Johnston believes the new study confirms something AIDS specialists have long suspected. "People have really been concentrating for a really long time on this risk coming from protease inhibitors, more than anything else," Johnston said. "It makes sense to me."

HIV-positive patients receiving HAART need not panic, another expert said.