Abstract
IntroductionIntensive blood pressure (BP) lowering reduces the risk of major adverse cardiovascular events (MACE) in high risk patients. However, BP varies over the short- and long-terms and the minimum proportion of time at or below BP goal necessary for MACE reduction is unknown.HypothesisHigher time in therapeutic blood pressure range (TTBPR) is associated with lower all-cause and cardiovascular mortality and major adverse cardiovascular events in patients with hypertension.MethodsWe included subjects from the SPRINT (A Randomized Trial of Intensive versus Standard Blood-Pressure Control) with ≥ 2 BP readings (n=9248 [99% of all subjects]). TTR was calculated with the linear interpolation method using a BP goal of 110-130 mm Hg. Patients were categorized into 4 TTBPR groups (0-25%, 26%-50%, 51%-75%, 76%-100%). Cox proportional hazards regression adjusted for age, gender and ethnicity was used to determine the relationship of TTBPR group to MACE with 0-25% as the reference group.ResultsMean age was 68±9 years, 35% were women, 30% were black and median TTBPR was 46% (IQR, 21-72%). The hazard for the composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, other acute coronary syndromes and heart failure, decreased with increasing TTBPR (Figure 1 Panel A). In addition, lower risk for CV death (Figure 1 Panel B), myocardial infarction, stroke , heart failure and all-cause mortality was observed with higher TTBPR (Figure 2 Panels A-D). In general, a pattern was evident whereby MACE was lower in the 75-100% TTBPR group than the 25-50% and 50-75% groups.ConclusionsIn patients with hypertension, TTBPR may be a novel measure of BP control quality. A target TTBPR of at least 75% appears to be necessary for MACE reduction.