Home blood pressure in poorly controlled hypertension: relationship with ambulatory blood pressure and organ damage.

OBJECTIVES

(1) To assess whether home blood pressure measurement is a reliable alternative to ambulatory blood pressure monitoring for the evaluation of treated patients with inadequate blood pressure control at the clinic; and (2) to evaluate the relationship between home blood pressure and several target-organ damage markers.

BASIC METHODS

A cross-sectional study was performed in 225 treated hypertensive patients with persistently high blood pressure values at the clinic (systolic blood pressure 140 mmHg and/or diastolic blood pressure 90 mmHg). All study participants underwent clinic blood pressure measurement, 24-h ambulatory blood pressure and home blood pressure monitoring. A subgroup of patients underwent the following procedures: carotid echography (n=74), microalbuminuria determination (n=88) and echocardiography (n=43). We defined out-of-clinic normotension as an average ambulatory or home blood pressure less than 135 mmHg (systolic) and 85 mmHg (diastolic).

MAIN RESULTS

The sensitivity, specificity and positive and negative predictive values of the home blood pressure method for predicting out-of-clinic normotension (with the ambulatory method used as reference), expressed as percentages, were 50, 87, 64 and 79%, respectively. Systolic home blood pressure correlated significantly with left ventricular mass (r=0.33, P<0.05) and microalbuminuria (r=0.24, P<0.05). Similar correlation coefficients were found for systolic ambulatory blood pressure (r=0.32, P<0.05 and r=0.24, P<0.05, respectively). Clinic blood pressure did not correlate with either left ventricular mass or microalbuminuria (r=0.19, P=0.09 and r=0.19, P=0.24, respectively). Diastolic home blood pressure, but not ambulatory blood pressure, correlated negatively with mean carotid intima-media thickness (r=-0.27, P<0.05).

CONCLUSION

Our results suggest that, in patients with poorly controlled hypertension at the clinic, home blood pressure represents a complementary test rather than an alternative to ambulatory blood pressure, and correlates with several target-organ damage markers.