Abstract 2745: Diagnostic Algorithm Using Office and Home Blood Pressures to Exclude White Coat Hypertension
Background: It has been suggested that the diagnosis of sustained hypertension (SHTN), defined as clinic blood pressure (CBP) ≥140 or ≥90 mmHg plus a daytime ambulatory BP (ABP) ≥135 or ≥85 mmHg can be optimized by taking home BP (HBP) in those with high CBP, and obtaining ABP only if HBP is normal (<135/85). This study tested whether a higher cutoff value for CBP using Receiver Operator Curves (ROC) based on systolic and diastolic CBP for the diagnosis of SHT (95% specificity) would improve the efficiency of the algorithm for diagnosing SHT and reduce the number of subjects requiring HBP and ABP to establish the diagnosis.
Methods and Results: We assessed CBP, ABP and HBP in 229 normotensive and untreated hypertensive subjects. CBP was high in 84 subjects. Of these, 74 (88%) had SHTN, and 10 (12%) white coat HTN (WCH- high CBP but normal ABP). With HBP, 69 (82%) had high HBP, and of these 63 (91%) had SHT. Based on traditional algorithm, 15 subjects require ABP monitoring to diagnose SHT, which would be confirmed in 11. Using the ROC algorithm, 55 of 84 subjects (50 SHT; 5 WCH) would be classified as ``hypertensive” (at or above the CBP cut-off); 29 subjects would fall below the cut-off and require HBP (with 24 having SHT); 5 subjects would require ABP. The sensitivity and specificity for diagnosing SHT were 100% and 40% for the traditional algorithm, and 100% and 20% for the ROC algorithm.
Conclusions: The ROC algorithm is as effective as the traditional algorithm for diagnosing SHT, and requires fewer HBPs (29 vs. 84) and ABPs (5 vs. 15). Therefore, this algorithm may have widespread indications for the screening of ambulatory hypertension.