Anti-hypertensive medication adherence in the REQUIRE trial: post-hoc exploratory evaluation.

Maintaining medication adherence is important in treating hypertension, especially resistant hypertension (RH), and variable medication adherence can confound results in blood pressure trials. This post-hoc analysis evaluated adherence at baseline and 3 months using available urine samples from the REQUIRE trial, comparing 24-h ambulatory systolic blood pressure (ASBP) lowering effects of ultrasound renal denervation (uRDN) versus sham in RH. At baseline, 45% (26/58) patients showed poor adherence. Among patients with good baseline adherence, adherence was unchanged at 3 months, and uRDN patients had a decreased ASBP whereas sham patients did not. In poorly adherent patients, sham patients showed a trend towards increased adherence and a significant ASBP reduction, whereas uRDN patients did not change. Accordingly, adherence changes and the resultant ASBP reduction in poorly adherent sham patients may explain the lack of between-group difference seen in REQUIRE. Monitoring and maintaining medication adherence is important for future interventional studies in RH.