Different systolic blood pressure targets and outcomes: a systematic review and meta-analysis of randomized trials

Abstract

Abstract Background Blood pressure (BP)-lowering is accompanied by a reduction of fatal or nonfatal outcomes in hypertensive patients. However, the achieved systolic BP target associated with higher outcome benefits remains unsettled. Purpose The aim was to determine the effects of BP-lowering treatment on outcome incidence at different achieved systolic BP strata. Methods A systematic review was conducted to identify randomized trials in electronic databases (Pubmed and CENTRAL, search between 1966 and 11/2022) for the effect of BP-lowering treatment against placebo or less aggressive treatment on the composite outcome of major cardiovascular (CV) events (i.e., myocardial infarction, stroke, and heart failure). Selected studies reported outcomes in patients with or without a history of previous CV disease. Studies were categorized according to the achieved level of systolic BP in the active or more actively treated group. Risk ratios (RR) were calculated with their 95% confidence interval (CI) under the random-effects model. Results We included 51 primary prevention studies (i.e., 16 trials in which systolic BP was lowered to values no less than 140 mmHg, n=36,189 patients; 22 trials with achieved systolic BP between 130 and 140 mmHg, n=84,952; and 13 trials with achieved systolic BP less than 130 mmHg, n=41,660) and 44 secondary prevention studies (i.e., 11 trials in which systolic BP was lowered to values no less than 140 mmHg, n=12,518 patients; 19 trials with achieved systolic BP between 130 and 140 mmHg, n=71,449; and 14 trials with achieved systolic BP less than 130 mmHg, n=39,085). For a standard systolic/diastolic BP reduction of 10/5 mmHg, the relative risk of the composite outcome was reduced in all achieved systolic BP strata, without a significant trend from higher to lower systolic BP targets, in both prevention groups. In addition, there was no difference in the absolute risk reduction of the combined outcome, as calculated by the number of events prevented in every 1000 patients treated for 5 years, between the systolic BP targets in each prevention group. However, only in primary prevention did a significant negative incremental trend from higher to lower systolic BP targets for the residual risk of the combined outcome become apparent. Conclusions Although antihypertensive treatment provides CV protection to all hypertensive patients, the lower systolic BP target is associated not only with outcome benefits but also with a lower rate of residual risk in primary prevention only.