Ambulatory versus clinic blood pressure in predicting overall subclinical target organ damage progression in essential hypertensive patients: a 3-year follow-up study.

BACKGROUND: Ambulatory blood pressure (BP) was shown to predict specific subclinical target organ damage (TOD) progression better than clinic BP, whereas the usefulness of ambulatory and clinic BP measurements to predict overall TOD progression is not well established.

METHODS AND RESULTS: Clinic and 24-h ambulatory BP values were obtained in 280 patients on baseline. A total of 199 participants (mean age 62.5±9.5, 59.3% men) were followed up for an average of 39 months and overall subclinical TOD were recorded at the end of follow-up period. Patients with increased TOD number had higher baseline clinic, 24-h, day and night systolic blood pressure (SBP), and pulse pressure, but baseline ambulatory and clinic diastolic blood pressure showed no differences. Multiple logistic regression analysis showed that the independent predictors of the overall TOD number increased were clinic [relative ratio (RR)=1.023, P=0.006], 24-h (RR=1.034, P=0.005), day (RR=1.023, P=0.04) and night (RR=1.038, P=0.001) SBP, as well as 24-h (RR=1.050, P=0.005), day (RR=1.037, P=0.02) and night (RR=1.062, P=0.001) ambulatory pulse pressure, and night average diastolic blood pressure with boundary correlation (RR=1.034, P=0.048). The night-time SBP value was more strongly associated with the risk of overall increased TOD number than the daytime (RR=1.049, P=0.003) or clinic SBP (RR=1.026, P=0.02). Similarly, 24-h pulse pressure was superior to clinic (RR=1.045, P=0.02) and night-time was superior to daytime pulse pressure (RR=1.104, P=0.002).

CONCLUSION: The risk of overall subclinical TOD progression increased more with a given increase in baseline ambulatory night-time BP than baseline clinic or daytime BP in essential hypertension.