Antihypertensive drug effects on long-term blood pressure: an individual-level data meta-analysis of randomised clinical trials

Objective Evidence from randomised trials of pharmacological treatments on long-term blood pressure (BP) reduction is limited. We investigated the antihypertensive drug effects on BP over time and across different participant characteristics. Methods We conducted an individual patient-level data meta-analysis of 52 large-scale randomised clinical trials in the Blood Pressure Lowering Treatment Trialists' Collaboration using mixed models to examine treatment effects on BP over 4 years of mean follow-up. Results There were 363 684 participants (42% women), with baseline mean age=65 years and mean systolic/diastolic BP=152/87 mm Hg, and among whom 19% were current smokers, 49% had cardiovascular disease, 28% had diabetes and 69% were taking antihypertensive treatment at baseline. Drugs were effective in lowering BP showing maximal effect after 12 months and gradually attenuating towards later years. Based on measures taken >= 12 months postrandomisation, mean systolic/diastolic BP difference (95% CI) between more and less intense BP-lowering treatment was -11.1 (-11.3 to -10.8)/-5.6 (-5.7 to -5.4) mm Hg; between active treatment and placebo was -5.1 (-5.3 to -5.0)/-2.3 (-2.4 to -2.2) mm Hg; and between active and control arms for drug comparison trials was -1.4 (-1.5 to -1.3)/-0.6 (-0.7 to -0.6) mm Hg. BP reductions were observed across different baseline BP values and ages, and by sex, history of cardiovascular disease and diabetes and prior antihypertensive treatment use. Conclusion These findings suggest that BP-lowering pharmacotherapy is effective in lowering BP, up to 4 years on average, in people with different characteristics. Appropriate treatment strategies are needed to sustain substantive long-term BP reductions.

Automated summary

This study conducted a meta-analysis of individual patient-level data from randomized clinical trials to investigate the long-term effects of antihypertensive drugs on blood pressure. The results showed that antihypertensive drugs were effective in lowering blood pressure, with maximal effect observed after 12 months and gradual attenuation over time. The findings suggest the need for appropriate treatment strategies to sustain long-term blood pressure reductions.