Cardiovascular Events Risk in Office-Masked Nocturnal Hypertension Defined by Home Blood Pressure Monitoring.

Background: Nocturnal home blood pressure monitoring (HBPM) may identify people at higher cardiovascular disease (CVD) risk than expected. Objectives: The aim of this study was to examine the association between office-masked nocturnal hypertension, defined by HBPM, and CVD risk in a clinical practice-based population. Methods: Prospective observational study including Japanese high cardiovascular-risk participants. Three office blood pressures (OBPs) were taken on two different occasions. Nocturnal home blood pressure (HBP) was measured three times per night for 2 weeks. The association between office-masked nocturnal hypertension and time to first CVD events (fatal and nonfatal stroke or coronary heart disease) was examined using Cox regression. Results: The cohort included 2,545 participants who were followed for a median of 7.8 years (18,116 person-years), during which 152 CVD events occurred. The proportions of participants with nocturnal normotension (OBP <140/90 mm Hg and nocturnal HBP <120/70 mm Hg), white-coat nocturnal hypertension (OBP ≥140/90 mm Hg and nocturnal HBP <120/70 mm Hg), office-masked nocturnal hypertension (OBP <140/90 mm Hg and nocturnal HBP ≥120/70 mm Hg), and sustained nocturnal hypertension (OBP ≥140/90 mm Hg and nocturnal HBP ≥120/70 mm Hg) were 25.3%, 14.4%, 23.2%, and 37.1%, respectively. Relative to nocturnal normotension, those with both office-masked nocturnal hypertension (adjusted HR: 1.72; 95% CI: 1.01-2.92) and sustained nocturnal hypertension (adjusted HR: 1.75; 95% CI: 1.03-2.96) had similarly increased CVD risk, even after adjustment for daytime HBP values. Conclusions: Screening for office-masked nocturnal hypertension with HBPM identifies a potentially important group of patients with increased risk for incident CVD events for whom additional preventative measures may be appropriate.