Defining Thresholds for Home Blood Pressure Monitoring in Octogenarians

Abstract

To generate outcome-driven thresholds for home blood pressure (BP) in the elderly, we analyzed 375 octogenarians (60.3% women; 83.0 years [mean]) enrolled in the International Database on home BP in relation to cardiovascular outcome. Over 5.5 years (median), 155 participants died, 76 from cardiovascular causes, whereas 104, 55, 36, and 51 experienced a cardiovascular, cardiac, coronary, or cerebrovascular event, respectively. In 202 untreated participants, home diastolic in the lowest fifth of the distribution (≤65.1 mm Hg) compared with the multivariable-adjusted average risk was associated with increased risk of cardiovascular mortality and morbidity (hazard ratios [HRs], ≥1.96; P≤0.022), whereas the HR for cardiovascular mortality in the top fifth (≥82.0 mm Hg) was 0.37 (P=0.034). Among 173 participants treated for hypertension, the HR for total mortality in the lowest fifth of systolic home BP (<126.9 mm Hg) was 2.09 (P=0.020). In further analyses of home BP as continuous variable (per 1-SD increment), higher diastolic BP predicted lower cardiovascular mortality and morbidity and cardiac and coronary risk (HR≤0.65; P≤0.039) in untreated participants. In those treated, cardiovascular morbidity was curvilinearly associated with systolic home BP with nadir at 148.6 mm Hg and with a 1.45 HR (P=0.046) for a 1-SD decrease below this threshold. In conclusion, in untreated octogenarians, systolic home BP ≥152.4 and diastolic BP ≤65.1 mm Hg entails increased cardiovascular risk, whereas diastolic home BP ≥82 mm Hg minimizes risk. In those treated, systolic home BP <126.9 mm Hg was associated with increased total mortality with lowest risk at 148.6 mm Hg.