Carotid Artery Imaging: Insights Into Inflammation and Cardiovascular Disease Risk in Patients With HIV Infection

A s patients with human immunodeficiency virus (HIV) livelonger because of advances in antiretroviral therapy, the importance of identifying and preventing non—AIDS-related causes of death has increased. Whether HIV infection, per se, increases risk of cardiovascular disease (CVD) remains an open question, because patients with HIV tend to have higher preva-lence of powerful traditional CVD risk factors such as smok-ing and dyslipidemia, as well as antiretroviral therapy—related risks. Most of the data suggesting that patients with HIV are at increased CVD risk comes from observational studies with im-portant methodological limitations, including short durations of follow-up, low CVD event rates, incomplete ascertainment of risk factors and events, and a lack of HIV-negative controls. Because patients with HIV tend to be relatively young and at low short-term CVD risk, research on CVD risks in patients with HIV has focused heavily on surrogate markers. One tech-nique, carotid ultrasound to measure intima-media thickness (IMT) and assess plaque presence, has been especially useful for studying CVD risk in individuals with HIV. A meta-analysis of 19 cross-sectional studies found significantly higher carotid IMT in individuals with HIV compared to HIV-negative con-trols, despite significant heterogeneity in published findings.1 Limitations aside, the primary findings of the meta-analysis were confirmed in a subsequent study that compared HIV-infected participants in FRAM (the Study of Fat Redistribution andMetabolic Change in HIV Infection) to HIV-negative individ-uals in MESA (the Multi-Ethnic Study of Atherosclerosis).2 Very few studies have evaluated whether HIV infection increases carotid IMT progression, and those studies were small and had mixed results. The opinions expressed in this article are not necessarily those of the editors