Peak nocturnal home blood pressure as an early and strong novel risk factor for stroke: the practitioner-based nationwide J-HOP Nocturnal BP study.

Clinical implications of high peak nighttime home blood pressure (BP) are currently unknown. This study investigated the association between peak nighttime home systolic BP (SBP) and cardiovascular events in individuals with at least one cardiovascular risk factor. In the Japan Morning Surge-Home Blood Pressure (J-HOP) study, nighttime home BP was automatically measured three times each night for 14 days at baseline using a nighttime home BP monitoring device (HEM-5001, Omron Healthcare). Peak nighttime home SBP was defined as average of the highest three values over the 14-night measurement period. Cardiovascular events (stroke, coronary artery disease, heart failure, aortic dissection) were tracked over a mean follow-up period of 7.1 years. This analysis included 2545 individuals (mean age 63.3 ± 10.3 years, 49% male). After adjusting for covariates (including age, sex, and average office, morning, evening, and nighttime home SBP), stroke risk was significantly higher in individuals with peak nighttime home SBP in the highest quintile (≥149.0 mmHg) compared to the lowest quintile (<119.3 mmHg) (hazard ratio [HR] 4.24, 95% confidence interval [CI] 1.07-16.77; p = 0.039 overall and 8.92, 1.49-53.43; p = 0.017 in the subgroup with ≥6 nighttime home SBP measurements). This increased stroke risk remained significant after controlling for day-by-day average real variability of nighttime BP. The average peak nighttime home SBP cut-off value for predicting an increased risk of incident stroke was 136 mmHg. We propose that exaggerated peak nighttime home SBP, determined from ≥6 measurements, is a novel risk factor for stroke, independent of conventional office and home BP values. The exaggerated peak nighttime home systolic blood pressure (HSBP) determined from six or more measurements as a novel risk factor for stroke, independent of conventional office and home blood pressure (BP) values.