Aims: Sleep-time blood pressure (BP) is a stronger risk factor for cardiovascular disease (CVD) events than awake and 24 h BP means, but the potential role of asleep BP as therapeutic target for diminishing CVD risk is uncertain. We investigated whether CVD risk reduction is most associated with progressive decrease of either office or ambulatory awake or asleep BP mean.
Methods and results: We prospectively evaluated 18 078 individuals with baseline ambulatory BP ranging from normotension to hypertension. At inclusion and at scheduled visits (mainly annually) during follow-up, ambulatory BP was measured for 48 consecutive hours. During the 5.1-year median follow-up, 2311 individuals had events, including 1209 experiencing the primary outcome (composite of CVD death, myocardial infarction, coronary revascularization, heart failure, and stroke). The asleep systolic blood pressure (SBP) mean was the most significant BP-derived risk factor for the primary outcome [hazard ratio 1.29 (95% CI) 1.22-1.35 per SD elevation, P < 0.001], regardless of office [1.03 (0.97-1.09), P = 0.32], and awake SBP [1.02 (0.94-1.10), P = 0.68]. Most important, the progressive attenuation of asleep SBP was the most significant marker of event-free survival [0.75 (95% CI 0.69-0.82) per SD decrease, P < 0.001], regardless of changes in office [1.07 (0.97-1.17), P = 0.18], or awake SBP mean [0.96 (0.85-1.08), P = 0.47] during follow-up.
Conclusion: Asleep SBP is the most significant BP-derived risk factor for CVD events. Furthermore, treatment-induced decrease of asleep, but not awake SBP, a novel hypertension therapeutic target requiring periodic patient evaluation by ambulatory monitoring, is associated with significantly lower risk for CVD morbidity and mortality.