Prognostic Value of a Riser Pattern of Nighttime Blood Pressure in Very Elderly Adults of ≥80 Years: A General Practice-Based Prospective SEARCH Study

BACKGROUND: We examined our hypothesis that participants with higher mean nighttime blood pressure (BP) levels and/or those with a riser BP pattern, both measured by ambulatory blood pressure (BP) monitoring (ABPM), would show higher risk for cardiovascular disease (CVD) events compared to those with normal nighttime BP levels or a normal dipper BP pattern of circadian BP rhythm, even in very elderly participants in a general practice population. METHODS: This prospective observational study enrolled 485 very elderly outpatients of ≥80 years (mean age: 83.2 ± 3.3 years; 44.7% male; 89.3% using antihypertensive medications). The prevalences of extreme dipper, dipper, nondipper, and riser status were 15.5%, 38.6%, 32.2%, and 13.8%, respectively. RESULTS: During a mean follow-up of 3.9 years (1,734 person-years), 41 CVD events occurred. The participants with a riser pattern (higher nighttime systolic BP [SBP] than daytime SBP) showed a significantly higher risk for CVD events with adjustment for covariates: hazard ratio (HR), 2.61; 95% confidence interval (CI), 1.03-6.62. Even after adjusting for covariates and mean nighttime SBP level, the CVD risks in participants with a riser pattern remained significant: HR, 3.11; 95% CI, 1.10-8.88. On the other hand, all BP variables showed no significant risks for CVD events. In addition, when we divided study participants into quartiles by their ambulatory BP levels, none of the ambulatory BP variables showed a J- or U-shaped relationship with CVD event risk. CONCLUSIONS: In very elderly general practice outpatients, a riser BP pattern was significantly associated with CVD events independently of mean nighttime BP.