Interruption of Antiretroviral Therapy and Risk of Cardiovascular Disease in Persons with HIV-1 Infection: Exploratory Analyses from the SMART Trial

Abstract

The SMART trial found a raised risk of cardiovascular disease (CVD) events in patients undergoing CD4+ T cell-count guided intermittent antiretroviral therapy (ART) compared with patients on continuous ART. Exploratory analyses were performed to better understand the reasons for this observation. A total of 5,472 patients with CD4+ T-cell counts >350 cells/mm3 were recruited and randomized to either continuous ART (the viral suppression arm; VS) or CD4+ T-cell count-guided use of ART (the drug conservation arm; DC). Major CVD events developed in 79 patients. The hazard ratio (HR) for risk of CVD events for DC versus VS was 1.57 (95% confidence interval 1.00-2.46; P=0.05). There was no evidence that being off ART or a higher current HIV viral load were associated with increased CVD risk. Total cholesterol and low-density lipoprotein cholesterol were reduced as a result of ART interruption in DC patients but so was high-density lipoprotein (HDL) cholesterol, leading to a net unfavourable change in the total/HDL cholesterol ratio. Reasons for the higher risk of CVD for DC compared with VS patients remain unclear. There was no clear evidence to suggest that ART interruption per se or a higher HIV viral load were associated with an increased CVD risk in the DC group. Lipid changes were less favourable among DC compared with VS patients, which could offer a partial explanation.