MONDAY, Aug. 31, 2026 (HealthDay News) -- Lower adherence to blood pressure-lowering medication is associated with no benefit for preventing cardiovascular events, according to a study presented at the annual meeting of the European Society of Cardiology, held from Aug. 28 to 31 in Munich.Qianqian Yang, from the University of Oxford in the United Kingdom, and colleagues conducted a systematic literature review to examine studies assessing whether and to what extent medication adherence modifies the blood pressure and cardiovascular effects of antihypertensive therapy in randomized trials.Based on data from 12 trials (115,389 participants), the researchers found that adherence declined over time in both intervention and comparator groups. Mean adherence was 88 percent in the intervention group at one year and 87 percent in the comparator group. For the studies with longitudinal data (nine studies; 91,339 participants), after five years, adherence decreased to 80 and 77 percent, respectively. During a median follow-up of 4.7 years, compared with the control group, the intervention reduced systolic blood pressure by −3.0 mm Hg in the lower-adherence stratum and by −5.2 mm Hg in the higher-adherence stratum (P for interaction < 0.001). By adherence stratum, the treatment effect on major cardiovascular disease significantly differed (hazard ratio, 0.89 [95 percent confidence interval, 0.86 to 0.92] in the higher-adherence stratum versus 1.01 [95 percent confidence interval, 0.92 to 1.10] in the lower-adherence stratum)."Notably, our results reinforce the saying that 'drugs don't work in patients who don't take them,'" Yang said in a statement. "Patients with lower adherence derived little or no cardiovascular benefit, whereas those with higher adherence had greater reductions in blood pressure and prevention of cardiovascular events."Press ReleaseMore Information .Sign up for our weekly HealthDay newsletter