Predictors of All-Cause Mortality in Clinical Ambulatory Monitoring

Abstract

Abstract-The prognostic value of sleep blood pressure reported by recent studies is variable. Our aim was to examine the relationship of sleep blood pressure, measured by 24-hour ambulatory blood pressure monitoring, with all-cause mortality. We studied a cohort of 3957 patients aged 55Ϯ16 (58% treated) referred for ambulatory monitoring (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005) Key Words: ambulatory blood pressure monitoring Ⅲ dipping Ⅲ mortality Ⅲ cohort Ⅲ sleep blood pressure D ata generated by 24-hour ambulatory blood pressure monitoring (ABPM) have been used to predict cardiovascular morbidity, as well as cardiovascular and all-cause mortality. [1][2][3][4][5][6][7][8][9] There is mounting evidence that this predictive ability is in part unrelated to clinic blood pressure (BP) measurements. Conceivably, ABPM reflects physiological states that are not captured by resting clinic measurements. 9 Moreover, ABPM reduces the influence of the measurement itself on BP values, namely the white-coat effect. In addition, ambulatory monitoring may unmask abnormal BP values that were not detected in the office. Thus, it is expected that ABPM would predict mortality above and beyond clinic measurements. There is still debate, however, whether in reality this is indeed the case and whether the use of this burdensome technique in clinical care is justified and contributes to patient management. 5 Another issue under debate concerns which component of the 24-hour ambulatory monitoring incorporates the most valuable prognostic information. Measurements taken during the waking state reflect, in part, physical activity, which may differ within and between patients. Thus, we hypothesized that, compared with awake BP, sleep measurements would relate to prognosis in a more profound way. Indeed, some 1,3,5,7,10,11 but not all 2 of the outcome studies have suggested this previously.In this study, we investigated all-cause mortality among patients who underwent ambulatory monitoring in a single center since 1991. We highlight sleep BP data identified by recorded sleeping periods, including afternoon naps. 12 We show that sleep BP, as well as nocturnal BP reduction (dipping, a somewhat controversial and infrequently studied topic 7,9,10,13 ) have independent predictive power. Methods Study PopulationData were extracted from our entire ABPM service database, from 1991 through 2005. All of the patients were included, except those Ͻ16 years old, pregnant women, and subjects with poor-quality ABPM (Ͻ50 valid measurements). Patients were referred for standard clinical indications at the discretion of the referring physician (mainly primary care practitioners, who have been shown to use ABPM for appropriate indications 14 ). We were not involved in the clinical care of these patients. Baseline data collected included demographic characteristics (age: 55 years [range: 16 to 93 years], sex (53% female), ethnicity (94% Jewish and 6% non-Jewish, predominantly Moslem Arabs), height (1.67 m; range...

Twenty-four hour ambulatory blood pressure for the management of antihypertensive treatment: a randomized controlled trial

“…Thus, this study suggests that home blood pressure measurement may be a suitable alternative if a correct blood pressure target is chosen, but more studies are needed before home blood pressure can be recommended for antihypertensive treatment titration. Finally, it has to be emphasized that in contrast to home blood pressure measurement, 24-h blood pressure measurement can give additional important information about night-time blood pressure, 9 dipping status [26][27][28] or 24-h blood pressure variability, 13 all of which may lead to improved risk stratification of individuals with hypertension. On the other hand, potential drawbacks of 24-h blood pressure measurement include additional costs and patient discomfort.…”

Nocturnal blood pressure and cardiovascular disease: a review of recent advances

“…Nevertheless, increasing evidence suggests that nocturnal BP is the more sensitive predictor of CVD outcomes than either daytime or 24-hour BP, and thus nocturnal BP measurement is becoming an important part of clinical practice. [1][2][3][4][17][18][19][20] NOCTURNAL BP AND CARDIOVASCULAR RISK A recent systematic review of 23 856 hypertensive patients and 9641 subjects from population cohorts from Asia, Europe and South America by Hansen et al 20 revealed that nocturnal BP is a significant risk factor for mortality and cardiovascular morbidity in both hypertensive patients and the general population, even when adjustments were made for daytime BP. The hazard ratios associated with each 10-mm Hg increase in nocturnal systolic BP were 1.16 or 1.14 for total mortality and 1.19 or 1.15 for cardiovascular morbidity in hypertensive patients or the general population, respectively (both Po0.001).…”

“…For example, an untreated man whose daytime BP 30 In contrast, other reports have concluded that a patient with this profile would be at increased mortality risk, regardless of the patient's 24-hour BP levels. [17][18][19][20]30 The clinical implications of nondipping in the absence of nocturnal hypertension may vary with age, smoking status, presence of antihypertensive drugs and co-morbidities such as diabetes, chronic kidney disease and preexisting CVD. Nevertheless, the association of nondipping with excess mortality rather than cardiovascular morbidity [17][18][19][20][21] raises the possibility that nondipping is a marker of pre-existing or concurrent diseases ( Figure 2).…”

Increased nighttime blood pressure or nondipping profile for prediction of cardiovascular outcomes

“…38 In another prospective study that recruited 3957 patients, a superior prognostic significance for all-cause mortality was attributed to nocturnal hypertension in comparison with the nondipping status defined according to either systolic BP or diastolic BP fall. 6 A meta-analysis of 3468 hypertensive patients' nighttime ambulatory BP significantly predicted allcause CV and non-CV mortality, coronary heart disease and stroke, independently of confounders. In addition, nighttime ambulatory BP adds to the prognostic significance of daytime ambulatory BP for all of the end points.…”

“…2 Along with 24-h systolic and diastolic BP, both reflecting the cardinal clinical components of the haemodynamic load magnitude, the prognostic impact of diverse time-dependent ABPM components (namely daytime and nighttime BP) and circadian BP variability patterns (such as dipping status, nightto-day BP ratio, early morning surge) have been previously investigated. 3 Although both averaged nocturnal BP values [4][5][6] and blunted nocturnal decrease with respect to daytime BP [7][8][9] were found to be associated with subclinical target organ damage and to heighten CV morbidity and mortality, their relative importance is still controversial.…”