LOWERING OF HOME BLOOD PRESSURE DIAGNOSIS THRESHOLDS TO 130/80 MMHG: IMPROVING DIAGNOSIS ACCURACY FOR HYPERTENSION

Objective: We evaluated whether lowering the home blood pressure (BP) threshold for hypertension diagnosis from 135/85 mmHg to 130/80 mmHg could improve the accuracy of hypertension diagnosis based on home BP. Design and method: Among 789 untreated individuals screened for hypertension diagnosis, 646 (mean age 52.0 ± 10.0 years, 310 men) with valid 3-day office, 7-day home, and 24-hour ambulatory BP data and an estimated glomerular filtration rate > 60 mL/min/1.73 m2 were included. Hypertension was classified into normotension (NT), white-coat hypertension (WH), masked hypertension (MH), and sustained hypertension (SH) based on office BP (>= 140/90 mmHg) and ambulatory BP (24-hour average >= 130/80 mmHg, daytime >= 135/85 mmHg, and/or nighttime >= 120/70 mmHg). Results: Lowering the home BP threshold to 130/80 mmHg increased diagnostic sensitivity from 72.3% to 89.5% but reduced specificity from 81.8% to 69.1%. Diagnostic accuracy was improved from 73.1% to 87.8% (kappa from 0.238 to 0.247). At the 135/85 mmHg threshold, 63.2% of MH and 15.1% of SH patients were classified as home normotension. In contrast, at the 130/80 mmHg threshold, 30.3% of MH and 3.4% of SH patients were categorized as home BP normotension. Among individuals with home BP between 130/80 mmHg and 134/84 mmHg, 46.8% had MH, and 46.8% had SH. These individuals exhibited higher office and ambulatory BP levels than those with home BP <130/80 mmHg but lower levels than those with home BP >=135/85 mmHg. Additionally, within this range, 22.9% were found to have isolated nighttime hypertension (INHT), and 60.6% exhibited daytime-night hypertension (DNHT). Conclusions: Given that the home BP diagnostic threshold of 135/85 mmHg leads to many patients with MH, SH, INHT, and DNHT being diagnosed as home normotension, and considering the high prevalence of these hypertension phenotypes in individuals with home BP between 130/80 mmHg and 134/84 mmHg, it is suggested that lowering the threshold to 130/80 mmHg or considering this range (130/80 mmHg to 134/84 mmHg) as a ’gray zone’ for further ambulatory BP monitoring may enhance diagnostic accuracy.