Abstract 09: The Diagnostic Accuracy of Using Borderline High Office Blood Pressure Thresholds to Diagnose Masked Hypertension According to the 2017 American College of Cardiology / American Heart Association Blood Pressure Guideline

Background: Compared to adults with sustained normotension (i.e. those with neither high office blood pressure BP nor high out-of-office BP), adults with masked hypertension (i.e. those with high out-of-office BP but not high office BP) have an increased risk of cardiovascular disease events. The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) BP guideline recommends using ambulatory BP monitoring (ABPM) to detect masked hypertension among adults with an office BP close to the high BP threshold (i.e. office systolic BP SBP 120 to <130 mmHg or diastolic BP DBP 75 to <80 mmHg) and not taking antihypertensive medication (Class IIa recommendation). Limited data exist on the diagnostic accuracy of using this approach to detect masked hypertension. Methods: We analyzed data from the Improving the Detection of Hypertension Study, a community-based study of adult participants, from Upper Manhattan, not taking antihypertensive medication. Office BP was measured using a validated Omron oscillometric device (Model HEM-790IT or HEM-791IT) and ABPM was performed using a validated Spacelabs device (Model 90207). Sensitivity (SN), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), false positive rate (FPR), and false negative rate (FNR) of having an office SBP 120 to <130 mmHg or DBP 75 to <80 mmHg for the diagnosis of high BP on ABPM were determined among 263 participants who had a mean SBP <130 mmHg and mean DBP <80 mmHg based on 6 SBP and 6 DBP readings from the first 2 visits (i.e. 3 SBP and 3 DBP readings per visit), and a sufficient number of ABPM readings (i.e. ≥10 awake and ≥5 asleep readings). High BP on ABPM was defined as mean awake SBP ≥130 mmHg or mean awake DBP ≥80 mmHg as per the 2017 ACC/AHA BP guideline. In a sensitivity analysis, high BP on ABPM was defined as mean 24-hour SBP ≥125 mmHg or mean 24-hour DBP ≥75 mmHg. Results: Mean (SD) age was 39.2 (12.8) years, 62.4% were female, 16.7% were non-Hispanic White, 14.4% were non-Hispanic Black, 6.8% were non-Hispanic Asian, 60.8% were Hispanic, and 1.3% were Other race/ethnicity. Of the 263 participants, 101 (38.4%) had an office SBP 120 to <130 mmHg or DBP 75 to <80 mmHg, and 69 (26.2%) had high BP on ABPM (awake SBP/DBP ≥130/80 mmHg). SN, SP, PPV, NPV, FPR, and FNR were 75.4%, 74.7%, 51.5%, 89.5%, 25.3%, and 24.6%, respectively. When using mean 24-hour SBP/DBP to define high BP on ABPM, SN, SP, PPV, NPV, FPR, and FNR were 72.7%, 75.8%, 55.4%, 87.0%, 24.2%, and 27.3%, respectively. Conclusions: The 2017 ACC/AHA BP guideline currently would require only 38.4% of participants with mean office BP <130/80 mmHg to be screened with ABPM for masked hypertension using a screening office BP threshold of SBP 120 to <130 mmHg or DBP 75 to <80 mmHg. However, this approach had a substantial rate of false positives and false negatives. Investigation of alternative diagnostic screening approaches for masked hypertension is needed.