Continuation of the ESH-CHL-SHOT trial after publication of the SPRINT: rationale for further study on blood pressure targets of antihypertensive treatment after stroke
Abstract
All major recent guidelines on hypertension management [1-3] acknowledge that evidence from randomized controlled trials (RCTs) is scanty and controversial about the levels to which blood pressure (BP) should be brought by antihypertensive treatment, in both primary and secondary prevention. Although observational studies have shown that there is a direct relationship between SBP and DBP and major cardiovascular events [both stroke and coronary heart disease (CHD) events] down to 115 mmHg SBP and 75 mmHg DBP [4], the numerous randomized trials that have demonstrated the benefits of BP lowering have very rarely brought SBP below 130 mmHg, and in most RCTs active treatment achieved SBP values either between 140 and 150 mmHg or a few mmHg below 140 mmHg [1].
Data suggesting that risk of cardiovascular disease events may be less effectively prevented when SBP (or DBP) is lowered below a given level (so called J-shaped curve) can only be considered hypothesis raising, as the type of analysis used (plotting incident outcomes against achieved BP independently of the randomized group) is an analysis of observational data, even if data are collected within a randomized trial.