Association of incomplete adherence to antiretroviral therapy with cardiovascular events and mortality in virologically suppressed persons with HIV: the Swiss HIV Cohort Study

Background Incomplete antiretroviral therapy (ART) adherence, even if sufficient to maintain viral suppression, is associated with enhanced inflammation in persons with HIV (PWH). However, its clinical implications remain unknown. Methods PWH enrolled in the Swiss HIV Cohort Study without a history of cardiovascular disease (CVD) who initiated ART between 2003 and 2018 and had viral suppression (<50 copies/mL) for ≥6 months were evaluated. The association between incomplete self-reported ART adherence (≥1 or ≥2 missed doses in the last month) and (1) any CVD event (myocardial infarction, revascularization, cerebral hemorrhage, stroke, and/or death due to CVD event) or (2) non-CVD-related death was evaluated using adjusted Cox proportional hazards models. Results A total of 6971 PWH (74% male) were included in the analysis (median age [interquartile range {IQR}], 39 [32-47] years). The median (IQR) follow-up was 8 (4-11) years, with 14 (8-23) adherence questionnaires collected per participant. In total, 205 (3%) participants experienced a CVD event, and 186 (3%) died a non-CVD-related death. In an adjusted competing risk model where missing data were imputed, missing ≥1 ART dose showed an increased, but not statistically significant, risk for CVD events (hazard ratio [HR], 1.23; 95% CI, 0.85-1.79; P = .28). Non-CVD-related mortality showed a statistically significantly increased risk with missing ≥1 ART dose (HR, 1.44; 95% CI, 1.00-2.07; P = .05) and missing ≥2 ART doses (HR, 2.21; 95% CI, 1.37-3.57; P = .001). Conclusions Incomplete ART adherence was significantly associated with an increased risk for non-CVD-related mortality in PWH with virologic suppression. This highlights the potential role of nonadherence to ART as a driver of non-AIDS clinical outcomes.