Abstract 031: Thresholds for Defining Home Blood Pressure Elevation Among US adults

Abstract

Background: Most hypertension guidelines have recommended lower home than clinic BP thresholds based on epidemiological studies conducted in non-US populations. However, diagnostic thresholds to define home BP elevation have never been determined in the general population in the United States. Methods: We analyzed data from 2 US cohorts with home and clinic BP data in the same participants, the Dallas Heart Study (DHS, n=5,768) and the North Carolina Masked Hypertension study (NCMH, n = 420). Home BP thresholds for stage 1 (BP ≥ 130/80 mmHg) and stage 2 hypertension (BP ≥ 140/90 mmHg) were identified using a regression-based approach in both cohorts and an outcome-derived approach in the DHS cohort. The composite of all-cause mortality or a cardiovascular disease (CVD) event was used in the outcome-derived approach. For this approach, BP thresholds were identified only for systolic BP (SBP) as clinic diastolic BP (DBP) was not associated with the outcome. Results: Among untreated participants in DHS, the regression-derived thresholds for home BP corresponding to clinic BP for stage 1 and stage 2 hypertension were 130/81 and 137/88 mmHg in blacks and 127/79 and 135/86 mmHg in nonblacks, respectively. The results are virtually identical in the NCMH cohort. The 11-year composite CVD and mortality events corresponding to stage 1 (clinic SBP ≥ 130) and stage 2 (clinic SBP ≥ 140 mmHg) were higher in untreated blacks than untreated non-blacks [13.3 (11.06-15.54) and 17.59 (14.8-20.37)% vs. 6.78 (5.17-8.39) and 9.86 (6.94-12.77)%, respectively]. Using a race/ethnicity-specific composite outcome, the outcome-derived thresholds from the DHS for home SBP corresponding to stage 1 and stage 2 hypertension were 131 and 140 mmHg in untreated blacks and 130 and 139 mmHg in untreated nonblacks, respectively. Conclusions: Based on the regression-derived approach, we found home BP thresholds for stage 1 and 2 hypertension from both cohorts to be similar to the current ACC/AHA guidelines. The outcome-derived approach also identified similar home SBP thresholds for stage 1 hypertension but slightly higher home SBP thresholds for stage 2 hypertension than recommended guidelines.