Does Adding Additional Antihypertensive Drugs Result in Progressively Diminished Effects?

Observational studies have suggested that the incremental benefits of blood pressure (BP) lowering diminish as the number of antihypertensive drugs prescribed increases. However, these observational studies might have been confounded by indication (i.e., when a treatment appears to be less effective because it is used in sicker people). In this analysis of data from SPRINT (NEJM JW Gen Med Dec 15 2015 and N Engl J Med 2015; 373:2103), a randomized trial, researchers assessed the incremental effects of adding antihypertensive drugs from a new class in >9000 nondiabetic hypertensive patients with heightened cardiovascular (CV) risk and no history of stroke; patients were randomized to either intensive BP lowering (systolic BP <120 mm Hg) or s…