SUBCLINICAL CORONARY ATHEROSCLEROSIS AMONG INDIVIDUALS WITH HIV ON ANTIRETROVIRAL THERAPY - PRELIMINARY RESULTS FROM THE CANADIAN HIV AND AGING COHORT STUDY (CHACS)

Abstract

The Canadian HIV and Aging Cohort Study (CHACS) is a large, controlled, prospective cohort recruiting participants living with HIV, and participants unexposed to HIV. The CHACS focus on identifying the prevalence, type and determinants of premature cardiovascular disease in HIV+ individuals. The objective of the present cardiovascular imaging substudy nested in the CHACS is to compare subclinical coronary plaque burden and characteristics between HIV+ and HIV- individuals and to evaluate the association of coronary plaque with HIV-related factors. This cross-sectional study was approved by our ethics committee. Participants provided written consent. Consecutive HIV+ and HIV- participants were prospectively recruited for cardiac computed tomography (CT). Eligibility criteria were absence of known coronary artery disease and low/intermediate 10-yr Framingham risk score (FRS, 5-20%). CT was used for calcium scoring and plaque assessment. Assessors were blinded to HIV status. Multivariate regression models were used. A total of 265 participants (181 HIV+ (92% males), 84 HIV- (77 % males)) were included (mean 56 yo), with similar FRS. Smoking (p < 0.001) and dyslipidemias (p ≤ 0.02) were increased in HIV+ participants. All HIV+ participants were on antiretroviral therapy. After adjusting for cardiovascular risk factors, burden of calcium and overall plaque was similar between HIV+ and HIV- participants. However, HIV+ participants had an increased volume (25 and 5 mm3/participant, p=0.03) of noncalcified plaques compared to HIV- participants. Prevalence and volume of calcified (p= 0.12 and 0.29) and mixed (p= 0.18 and 0.17) plaques, as well as ≥ 70% stenosis (p=0.99) were similar between HIV+ and HIV- participants. In HIV participants, total plaque volume, noncalcified plaque volume and mixed plaque volume (p=0.01, 0.03 and 0.006) increased with the use of protease inhibitors; noncalcified plaque volume (p=0.02) increased with the use of nucleoside reverse transcriptase inhibitors. To our knowledge, this is the largest Canadian imaging study of HIV-associated coronary atherosclerosis. In line with previous studies, our results confirm that asymptomatic HIV+ individuals under antiretroviral therapy have increased noncalcified plaque in comparison to HIV- individuals, after adjustment for cardiovascular risk factors. Noncalcified plaques are usually considered vulnerable and this finding could suggest one anatomic substrate for the known increased risk of myocardial infarction in the HIV population. Additionally, our data are intended as a basis for novel correlative analyses (e.g. carotid wall biomechanics, advanced immunological factors, frailty) planned with other teams of the CHACS.