Revisiting Cardiovascular Benefits of Blood Pressure Reduction in Primary and Secondary Prevention: Focus on Targets and Residual Risk-A Systematic Review and Meta-Analysis.

BACKGROUND:Previous meta-analyses resurrected the debated statement "the lower, the better" following blood pressure (BP)-lowering treatment. We investigated the benefits of BP-lowering treatment at different BP targets by prevention category. METHODS:The meta-analysis protocol was registered at the International Prospective Register of Systematic Reviews (CRD42022379249). The database included 115 BP-lowering or comparison trials from patients with (n=241 089) or without (n=198 937) previous cardiovascular events. Prevention disease groups were stratified by in-treatment achieved BP, drug class versus placebo, and drug class versus other classes. Risk ratios and 95% CIs of major adverse cardiovascular events were calculated. RESULTS:Following a standard (10/5 mm Hg) BP reduction, major adverse cardiovascular event relative risk reductions were not different between prevention groups (primary, 25% [95% CI, 18%-31%]; secondary, 28% [95% CI, 20%-37%]). For achieved systolic BP of at least 140 mm Hg, between 130 and 140 mm Hg, and <130 mm Hg (nadir, 125 mm Hg), (1) risk ratios of major adverse cardiovascular events and absolute risk reductions were not different between prevention groups across systolic BP strata, and (2) residual risk, though 4.1× greater in secondary than primary prevention, decreased in primary prevention from higher to lower systolic BP targets. The effect of separate drugs versus others on the primary outcome was not different between prevention groups. CONCLUSIONS:BP-lowering treatment benefits did not differ by prevention group to a nadir of 125 mm Hg for systolic BP. Although residual risk in secondary prevention is higher than in primary prevention, it gradually decreases at progressively lower systolic BP targets in primary prevention. REGISTRATION:URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42022379249.