The prognostic value of ambulatory blood pressure monitoring in treated hypertensive patients

Abstract

The clinical course of 459 treated hypertensive patients who wore the Remler M-2000 patient-activated, semi-automatic, portable blood pressure recorder was reviewed in order to determine whether the average awake ambulatory blood pressure was better able than office blood pressure and standard risk prognosticators to predict the development of cardiovascular morbid events. The patients who developed events were older, had higher office blood pressures and more evidence of target-organ damage, and were more likely to have suffered a clinical cardiovascular event before entry into the study. Ambulatory pressures were lower than office blood pressure in 78% of patients; the correlation coefficients were 0.67 for systolic pressure and 0.60 for diastolic pressure. Each patient was classified according to whether his observed ambulatory blood pressure was greater than or equal to 10/6 mmHg above, within 9/5 mmHg or greater than or equal to 10/6 mmHg below the level derived from his or her office blood pressure and the regression line derived from the scatter plot of ambulatory blood pressure on office blood pressure for the entire sample. Using life-table analyses to record the rate of development of a first cardiovascular event, and log rank tests to compare curves, significant differences in outcome were found between patients whose observed ambulatory blood pressure was above the regression line compared with those whose ambulatory blood pressure was below the regression line. We conclude that ambulatory blood pressure measurements can provide additional prognostic information to that available from office blood pressure and from the standard prognostic indicators, age and severity of disease.