Superiority of Ambulatory Over Clinic Blood Pressure Measurement in Predicting Mortality

Abstract

Abstract-The purpose of this study was to determine if ambulatory blood pressure measurement predicted total and cardiovascular mortality over and beyond clinic blood pressure measurement and other cardiovascular risk factors; 5292 untreated hypertensive patients referred to a single blood pressure clinic who had clinic and ambulatory blood pressure measurement at baseline were followed up in a prospective study of mortality outcome. Multiple Cox regression was used to model time to total and cause-specific mortality for ambulatory blood pressure measurement while adjusting for clinic blood pressure measurement and other risk factors at baseline. There were 646 deaths (of which 389 were cardiovascular) during a median follow-up period of 8. Key Words: blood pressure Ⅲ blood pressure monitoring, ambulatory Ⅲ cardiovascular diseases Ⅲ hypertension Ⅲ mortality T he most commonly used technique of blood pressure measurement in clinical practice is the auscultatory method with a mercury sphygmomanometer and stethoscope. A metaanalysis of clinic blood pressure measurement (CBPM) in 1 million adults participating in 61 prospective studies showed that a 10-mm Hg higher usual systolic blood pressure (SBP) or 5-mm Hg higher usual diastolic blood pressure (DBP) would be associated with Ϸ40% higher risk of stroke death and Ϸ30% higher risk of death from ischemic heart disease and other vascular causes. 1 There are, however, numerous criticisms of CBPM, which include interobserver and intraobserver variability, and terminal digit preferences, 2,3 all of which may bias the accuracy of measurement. Moreover, CBPM cannot detect white-coat hypertension, the prevalence of which can be as high as 30%. 4 There is growing evidence from a number of small studies that ambulatory blood pressure measurement (ABPM) is a better predictor of outcome than CBPM, 5-13 but only one large Japanese population study has shown ABPM to be better predictor of cardiovascular mortality than CBPM. 8 Similarly, evidence is accumulating to demonstrate that nighttime pressure is superior to daytime pressure in predicting cardiovascular outcome. 7,14 -21 The objective of this study, therefore, was to determine the additional predictive value of ABPM over and above CBPM, and also to estimate the superiority of nighttime pressure over daytime pressure in a large Western population of untreated hypertensive patients from a single center followed-up for up to 20 years. Methods Study PopulationThe Blood Pressure Unit (formerly located at the Charitable Infirmary and now based at Beaumont Hospital in Dublin) has been in operation for 22 years. The majority of patients are referred to the Correspondence to Eoin O'Brien,

Ambulatory pulse pressure as a novel predictor for long-term prognosis in essential hypertensive patients

“…2 Many studies have confirmed superiority of 24-h ambulatory BP monitoring (ABPM) over office or clinic BP measurement in predicting hypertension-induced organ damage or clinical outcome. [3][4][5][6] To what extent ABPM provides an independent predictive value beyond office BP is of clinical importance, as ABPM is potentially more burdensome and associated with higher costs than office or clinic BP measurements. Previous study mainly focused on ambulatory systolic BP (SBP) 3,4,6,7 or diastolic BP (DBP).…”

“…[3][4][5][6] To what extent ABPM provides an independent predictive value beyond office BP is of clinical importance, as ABPM is potentially more burdensome and associated with higher costs than office or clinic BP measurements. Previous study mainly focused on ambulatory systolic BP (SBP) 3,4,6,7 or diastolic BP (DBP). 3,4 Variation in the day-night BP pattern (the dipping status) has also been claimed as an important predictor of both target-organ damage and CV events.…”

“…Previous study mainly focused on ambulatory systolic BP (SBP) 3,4,6,7 or diastolic BP (DBP). 3,4 Variation in the day-night BP pattern (the dipping status) has also been claimed as an important predictor of both target-organ damage and CV events. 4,6,8 However, the roles of other parameters derived from ABPM, including 24-h pulse pressure (PP), daytime PP and nighttime PP, are not fully defined.…”

“…3,4 Variation in the day-night BP pattern (the dipping status) has also been claimed as an important predictor of both target-organ damage and CV events. 4,6,8 However, the roles of other parameters derived from ABPM, including 24-h pulse pressure (PP), daytime PP and nighttime PP, are not fully defined. Further, previous studies were mainly conducted in Europe 3,4,6 and Japan.…”

“…4,6,8 However, the roles of other parameters derived from ABPM, including 24-h pulse pressure (PP), daytime PP and nighttime PP, are not fully defined. Further, previous studies were mainly conducted in Europe 3,4,6 and Japan. 5 Both environmental and genetic factors 9 of hypertension may be different among different ethic populations.…”