Anti-HIV Treatment Lowers Cardiovascular Risk

Antiretroviral medications for HIV do not seem to increase the risk of cardiovascular events, suggest a pair of studies in the August issue of AIDS. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

To the contrary, effective treatment that preserves immune system function appears to be the most important factor in lowering cardiovascular risk among HIV-positive patients, according to the two studies. Attempting to overcome the challenges of researching this complex issue, both studies focused on "surrogate markers" of cardiovascular risk in large, well-documented data bases of patients with HIV disease.

HAART Linked to Reduced Coronary Artery Calcium
A study led by Lawrence A. Kingsley, Dr.P.H., of University of Pittsburgh used a specialized CT scan to measure levels of calcium in the coronary arteries of approximately 950 men, some HIV-positive and some HIV-negative. Of the HIV-positive subjects, some had received highly active antiretroviral therapy (HAART) treatment and some had not. Coronary artery calcium—reflecting the buildup of atherosclerosis ("hardening" of the arteries)—is a known predictor of later coronary events.

For HIV-positive and HIV-negative men alike, the factor most strongly related to the presence of coronary artery calcium was older age. Taking into account other cardiovascular risk factors—including smoking, cholesterol, and blood pressure—HIV-positive men were somewhat more likely to have coronary artery calcium.

However, after adjustment for all of these risk factors, patients taking HAART had lower amounts of coronary artery calcium. Among HIV-positive men who were not taking cholesterol-lowering drugs, coronary artery calcium scores were about 60 percent lower for those who had been on HAART for 8 years or longer.

Low CD4+ Cell Counts Are a Risk Factor for Carotid Atherosclerosis
The second study—led by Dr. Robert Kaplan of Albert Einstein College of Medicine, Bronx, N.Y.—used ultrasound techniques to measure indicators of atherosclerosis in the carotid arteries supplying the brain, which are early markers of stroke and heart disease risk. The study included data on 2,790 men and women, some HIV-positive and some HIV-negative.

The results showed that a low CD4+ cell count—a lab test of immune system function, which rises with effective anti-HIV treatment—was strongly linked to increased carotid artery atherosclerosis. For HIV-positive patients with a CD4+ cell count of less than 200 cells per cubic millimeter, the risk of carotid atherosclerosis was 100 percent higher for women and 74 percent higher for men. For the most part, the use of antiretroviral medications was unrelated to carotid atherosclerosis.