Abstract
High medication burden is associated with poor treatment effect and high risk of cardiovascular outcomes. This study aimed to investigate the association between the antihypertensive medication burden and cardiovascular outcomes in the STEP trial. This post-hoc analysis of the STEP trial enrolled 8511 participants, including 8041 with low burden and 470 with high burden. High antihypertensive medication burden was defined as being treated with ≥3 different classes of prescribed antihypertensive medications. The primary outcome was a composite of cardiovascular outcomes. Fine-Gray model was used in this study. Among all participants, high antihypertensive medication burden was associated with a higher risk of the primary outcome compared with low medication burden (HR, 1.52; 95% CI, 1.03-2.24), which was consistent in the standard group (HR, 1.95; 95% CI, 1.20-3.18) and the intensive group (HR, 1.10; 95% CI, 0.57-2.13; P(interaction) = 0.18). The beneficial effects of intensive systolic blood pressure (SBP) control on the primary outcome remained significant in the high burden group (HR, 0.42; 95% CI, 0.19-0.95) and the low burden group (HR, 0.79; 95% CI, 0.63-0.98; P(interaction) = 0.18). At 24 months, the percentage of participants achieving the target SBP was lower in the high medication burden group (risk ratio, 0.93; 95% CI, 0.89-0.98). In both standard and intensive treatment groups, participants with a high medication burden were harder to achieve the target SBP (P(interaction) = 0.65). High antihypertensive medication burden was associated with worse SBP control and a greater risk of cardiovascular events. Intensive SBP control showed cardiovascular benefits in both medication burden groups. Trial registration: STEP ClinicalTrials.gov number, NCT03015311. Registered 2 January 2017.