Several studies have noted increased risk for coronary artery disease (CAD) and myocardial infarction in HIV-infected patients. This increase has been attributed to direct effects — or metabolic complications — of antiretroviral therapy (ART), factors associated with the virus itself (including chronic immune activation), or both. Surrogate markers of atherosclerotic disease have been used to further characterize this risk in HIV-infected patients.
Now, as part of the large, prospective Multicenter AIDS Cohort Study (MACS), researchers have used noncontrast cardiac computed tomography (CT) to measure coronary artery calcium (CAC) and CT angiography to assess plaque extent and characteristics. A total of 618 HIV-infected and 383 HIV-uninfected men who have sex with men underwent cardiac CT; 759 of the participants without contraindications to CT angiography also underwent this procedure. Data on CAD risk factors and HIV clinical variables were obtained from records for previous MACS visits.
In multivariate analyses adjusted for age, race, CT scanning center, cohort, and established CAD risk factors, the prevalence and extent of CAC were similar between HIV-infected and uninfected men. However, HIV-infected men had a significantly greater prevalence of plaque in any coronary segment and of noncalcified plaque, and a significantly greater extent of noncalcified plaque. In the HIV-infected group, lower nadir CD4-cell counts and longer ART duration were associated with coronary artery stenosis >50%.
Dr. Armstrong is Medical Director of the Infectious Diseases Program at Grady Health System and Associate Professor of Infectious Diseases at Emory University School of Medicine, Atlanta. She reports no conflicts of interest.