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.

HIV Treatment Is “Good for the Heart”
Previous studies had suggested that certain antiretroviral drugs might increase the risk of atherosclerosis or cardiovascular events. However, other studies gave contradictory results, while HIV itself has been shown to nearly double the risk of myocardial infarction (heart attack). Because of the large number of patients and very long-term follow-up that would be needed, it is unlikely that a randomized trial will be conducted to answer this question.

The new studies, using surrogate markers linked to a high risk of later cardiovascular disease, lend new insights into how anti-HIV therapies affect risk. Together, the reports suggest that antiretroviral medications and the resulting improvements in immune function are linked to reductions, not increases, in cardiovascular risk.

Large studies in HIV-positive patients starting antiretroviral therapy will provide further insights into the cardiovascular effects, according to an accompanying editorial by Drs. Robert Murphy and Dominique Costagliola of University of Paris Medical Center. Meanwhile, the new results suggest that getting recommended treatment is probably the most important step patients can take to lower their cardiovascular risk. Drs. Murphy and Costagliola conclude, “One thing we can say with certainty is that treatment of HIV disease with restoration of immunity is good for the heart—this is the most important message today.”

Source: Wolters Kluwer Health: Lippincott Williams & Wilkins

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AIDS publishes the very latest ground-breaking research on HIV and AIDS. Read by all the top clinicians and researchers, AIDS has the highest impact of all AIDS-related journals. With 18 issues per year, AIDS guarantees the authoritative presentation of even more significant advances. The Editors, themselves noted international experts who know the demands of HIV/AIDS research, are committed to making AIDS the most distinguished and innovative journal in the field. Visit the journal website at http://www.aidsonline.com.

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