Redefining Blood-Pressure Targets — SPRINT Starts the Marathon

Blood pressure is a potent determinant of cardiovascular risk, but the most appropriate targets for blood-pressure lowering have long been debated. Observational studies with a low risk of confounding have shown a linear relationship between blood pressure and cardiovascular risk down to 115/75 mm Hg,1 but some observational studies with a greater potential for confounding, involving persons at increased risk, have suggested a J-shaped curve — that is, below a given blood pressure, risk would increase. When trials of blood-pressure–lowering drugs have shown benefits in patients without hypertension, these effects have often been ascribed to alternative mechanisms. The widespread uncertainty . . .