Cardiovascular events risk in office-masked nocturnal hypertension defined by home blood pressure monitoring: the J-HOP nocturnal blood pressure study

Abstract Background Elevated nocturnal home blood pressure (BP) has been reported to be associated with increased risk for cardiovascular disease (CVD). Masked hypertension defined by home BP monitoring is also a strong risk factor for adverse CVD outcomes. However, no study has investigated the association between office-masked nocturnal hypertension defined by home BP monitoring and CVD events risk. Purpose This study aimed to examine the association between office-masked nocturnal hypertension defined by home BP monitoring and CVD events risk in a clinical practice-based population. Methods This was a prospective observational study including Japanese participants with CVD or high risk of CVD. Three office BPs were taken on two different occasions. Nocturnal home BP was measured three times per night for two weeks. The association between office-masked nocturnal hypertension and incident total CVD events (including fatal and non-fatal stroke and coronary heart disease) was examined using Cox regression. Results 2,545 participants were followed for the mean of 7.1 years (18,116 person-years), during which 152 (6.0%) CVD events occurred. Mean age (standard deviation) was 63.3 (10.3) years; 49.0% were male; 82.6% took antihypertensive medications. The proportions of participants with normotension (office BP <140/90 mmHg and nocturnal home BP <120/70 mmHg), white-coat hypertension (office BP ≥140/90 mmHg and nocturnal home BP <120/70 mmHg), office-masked nocturnal hypertension (office BP <140/90 mmHg and nocturnal home BP ≥120/70 mmHg), and sustained hypertension (office BP ≥140/90 mmHg and nocturnal home BP ≥120/70 mmHg) were 25.3%, 14.4%, 23.2%, and 37.1%, respectively. The office-masked nocturnal hypertensive group and sustained hypertensive group had higher incidence rates of total CVD events compared with the normotensive group. Relative to normotension, those with both office-masked nocturnal hypertension (adjusted hazard ratio [aHR] 1.72, 95% confidence interval [CI] 1.01–2.92) and sustained hypertension (aHR 1.75, 95%CI 1.03–2.96) had similarly increased CVD risk, even after adjustment for daytime home BP values. Conclusions Screening for office-masked nocturnal hypertension with home BP monitoring identifies a potentially important group of patients with increased risk for incident CVD events for whom additional preventative measures may be appropriate.