Relative utility of home, ambulatory, and office blood pressures in the prediction of end-organ damage

Background: Home blood pressure (HBP) monitoring plays an increasingly important role in the diagnosis and treatment of hypertension. We evaluated the independent value of HBP compared with ambulatory blood pressure (ABP) and office blood pressure (OBP) in the prediction of cardiovascular end-organ damage in normotensive subjects and untreated patients with mild hypertension. Methods: One hundred sixty-three subjects underwent measurements of OBP, HBP, ABP, and echocardiography. A physician using a mercury-column sphygmomanometer performed three OBP measurements. The ABP was recorded using a noninvasive ambulatory monitor (mean, 35.4 awake readings per subject). Participants took HBP readings with an automatic, oscillometric device over a 10-week period (mean , 277.9 readings per subject). The left-ventricular mass index (LVMI) was calculated from measurements obtained from two-dimensionally guided M-mode or linear tracings on echocardiography. Results: For systolic and diastolic blood pressures (SBP/DBP), the correlation coefficients of the LVMI with OBP, awake ABP, and HBP were 0.29/0.27, 0.41/0.26, and 0.47/0.35, respectively (all P <.01). In a multivariate regression analysis in which age, sex, body mass index, OBP, awake ABP, and HBP were included, only age, sex, and HBP were significant predictors of LVMI. When only the first 12 home readings were used, the superiority of HBP was no longer evident. Conclusions: In contrast to OBP and ABP, HBP measurements, when averaged over a 10-week period, are independently related to LVMI. The HBP adds prognostic information over and above OBP and ABP in the prediction of cardiovascular end-organ damage, but this relationship appears to depend on the number of readings taken.