Large discrepancy between unobserved automated office blood pressure and ambulatory blood pressure in a high cardiovascular risk cohort

Objectives: Automated office blood pressure (AOBP) measurement has been shown to eliminate the white-coat effect and to be more concordant with ambulatory blood pressure monitoring (ABPM) and home blood pressure (BP) measurements. This study aimed to compare AOBP with ABPM in patients with a high cardiovascular risk. Methods and results: Participants were recruited from a prospective cohort study (Cardiovascular and Metabolic Disease Etiology Research Center-High Risk Cohort, clinicaltrials.gov: NCT02003781). A total of 1208 persons who had undergone both AOBP and ABPM within 7 days of each other were analyzed. The 95% limits of agreement between systolic AOBP and daytime ABPM SBP were -34.8 and 20.2 mmHg (mean difference = -7.3 +/- 14.0). The mean differences in blood pressure across quintiles of AOBP distributions increased with decreasing systolic AOBP [-17.8 +/- 11.2 (Q1, systolic AOBP < 113 mmHg), -10.9 +/- 11.1 (Q2, systolic AOBP 113-121 mmHg), -8.5 +/- 10.7 (Q3, systolic AOBP 121-128 mmHg), -4.2 +/- 11.8 (Q4, systolic AOBP 128-137 mmHg), 4.9 +/- 14.2 (Q5, systolic AOBP > 137 mmHg), P < 0.001]. The prevalence of masked hypertension phenomena was 310 (25.7%) and that of white-coat hypertension phenomena was 102 (8.4%). Large discrepancies were significantly associated with lower systolic AOBP, higher atherosclerotic cardiovascular disease risk score, and history of asymptomatic cardiovascular disease. Conclusion: The lower range of systolic AOBP exhibited a large discrepancy with daytime ABPM SBP. Moreover, higher cardiovascular risk was independently associated with larger discrepancy between AOBP and ABPM. The status of blood pressure control should be confirmed using out-of-office blood pressure measurements, even when using AOBP as a clinical BP reference in high-risk patients.