Outcome-driven thresholds for home blood pressure measurement: International database of home blood pressure in relation to cardiovascular outcome

The lack of outcome-driven operational thresholds limits the clinical application of home blood pressure (BP) measurement. Our objective was to determine an outcome-driven reference frame for home BP measurement. We measured home and clinic BP in 6470 participants (mean age, 59.3 years; 56.9% women; 22.4% on antihypertensive treatment) recruited in Ohasama, Japan (n=2520); Montevideo, Uruguay (n=399); Tsurugaya, Japan (n=811); Didima, Greece (n=665); and nationwide in Finland (n=2075). In multivariable-adjusted analyses of individual subject data, we determined home BP thresholds, which yielded 10-year cardiovascular risks similar to those associated with stages 1 (120/80 mm Hg) and 2 (130/85 mm Hg) prehypertension, and stages 1 (140/90 mm Hg) and 2 (160/100 mm Hg) hypertension on clinic measurement. During 8.3 years of follow-up (median), 716 cardiovascular end points, 294 cardiovascular deaths, 393 strokes, and 336 cardiac events occurred in the whole cohort; in untreated participants these numbers were 414, 158, 225, and 194, respectively. In the whole cohort, outcome-driven systolic/diastolic thresholds for the home BP corresponding with stages 1 and 2 prehypertension and stages 1 and 2 hypertension were 121.4/77.7, 127.4/79.9, 133.4/82.2, and 145.4/86.8 mm Hg; in 5018 untreated participants, these thresholds were 118.5/76.9, 125.2/79.7, 131.9/82.4, and 145.3/87.9 mm Hg, respectively. Rounded thresholds for stages 1 and 2 prehypertension and stages 1 and 2 hypertension amounted to 120/75, 125/80, 130/85, and 145/90 mm Hg, respectively. Population-based outcome-driven thresholds for home BP are slightly lower than those currently proposed in hypertension guidelines. Our current findings could inform guidelines and help clinicians in diagnosing and managing patients.