HIV and antiretroviral treatment are not hurting your heart any more than a doughnut addiction or that pack of cigarettes in your pocket. The results of two new studies confirm that HIV drugs, and possibly HIV infection itself, can increase the risk of a heart attack. But the numbers also reveal that the main heart disease culprits are the same as for everyone else: smoking and diabetes.

While the life-extending benefits of combo treatment have been quite clear for a decade now, there have long been grumblings of concern that people on HIV regimens were experiencing increased heart attacks and arterial blockages. Protease inhibitors (PIs) were fingered in several studies as the most likely to blame, given the body-fat changes, lipid problems and blood sugar spikes seen in clinical trials of these compounds.

The latest research presents a more complicated picture. “There does not appear to be an epidemic [of heart disease] on the horizon—simply a risk that needs to be managed,” according to James Stein, MD, of the University of Wisconsin School of Medicine, writing about one of the new studies in an April 26 New England Journal of Medicine (NEJM) editorial.

That study found that PIs boost a patient’s risk for a heart attack by 16% for every year they remained on that class of HIV drugs. Among those who remained on a non-nucleoside reverse transcriptase inhibitor (NNRTI), the annual risk was 5%, according to the study, which was conducted by the Data Collection on Adverse Events of Anti-HIV Drugs (DAD) study group (the largest ongoing evaluation of the long-term effects of antiretroviral therapy on cardiovascular disease).

The study followed 23,437 people living with HIV, hailing from 181 clinics in 21 countries. More than 90% of those enrolled were on antiretroviral treatment during the study. Over an average of 4.5 years of follow-up in the study, a total of 345 fatal and non-fatal heart attacks were documented.

The other study, led by Steven Grinspoon, MD, of Massachusetts General Hospital, analyzed medical records from more than 1.7 million patients treated at two major hospitals in Boston. According to their report, published in an online version of the Journal of Clinical Endocrinology and Metabolism, the researchers compared data involving almost 4,000 HIV-positive patients with information on more than a million HIV-negative patients. The risk for heart attack among people with HIV was almost double that among those without; it almost tripled among HIV-positive women.   

How should these findings be interpreted? Donald Kotler, MD, of St. Luke’s-Roosevelt Hospital Center in New York City, a longtime researcher of lipid-related problems in HIV-positive patients, cautions that the seemingly high risk percentages are not necessarily what they appear to be.  

“If the risk starts out low,” he says, “an extra 16% is not high. Even a doubling is not high. For example, if you are a young African-American woman, the risk of having a heart attack is on the order of 0.1% per year. According to DAD, this rises to 0.116% a year.”  

Dr. Stein writes, “The increased cardiovascular risk observed with protease inhibitors is not high, especially as compared with the effect of other cardiovascular risk factors”—specifically, aging, being male, being a current smoker or having a history of heart disease.

Stein adds: “Given the much greater cardiovascular risks associated with diabetes mellitus and with smoking (and the high prevalence of smoking among HIV-infected patients), perhaps more effort should be spent assisting our patients with smoking cessation and the prevention of diabetes, rather than focusing so intently on the [lipid-altering] effects of antiretroviral therapy.”  

Dr. Kotler agrees, but doubts that healthy lifestyle messages can compete with drug company marketing campaigns. “Clearly, the reason that people concentrate on drugs, not on lifestyle, is that there are greater profits in…drugs than in exercising, eating healthfully and not smoking.”