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Abstract-In previous studies, of which several were underpowered, the relation between cardiovascular outcome and blood pressure (BP) variability was inconsistent. We followed health outcomes in 8938 subjects (mean age: 53.0 years; 46.8% women) randomly recruited from 11 populations. At baseline, we assessed BP variability from the SD and average real variability in 24-hour ambulatory BP recordings. We computed standardized hazard ratios (HRs) while stratifying by cohort and adjusting for 24-hour BP and other risk factors. Over 11.3 years (median), 1242 deaths (487 cardiovascular) occurred, and 1049, 577, 421, and 457 participants experienced a fatal or nonfatal cardiovascular, cardiac, or coronary event or a stroke.Higher diastolic average real variability in 24-hour ambulatory BP recordings predicted (PՅ0.03) total (HR: 1.14) and cardiovascular (HR: 1.21) mortality and all types of fatal combined with nonfatal end points (HR: Ն1.07) with the exception of cardiac and coronary events (HR: Յ1.02; PՆ0.58). Higher systolic average real variability in 24-hour ambulatory BP recordings predicted (PϽ0.05) total (HR: 1.11) and cardiovascular (HR: 1.16) mortality and all fatal combined with nonfatal end points (HR: Ն1.07), with the exception of cardiac and coronary events (HR: Յ1.03; PՆ0.54). SD predicted only total and cardiovascular mortality. While accounting for the 24-hour BP level, average real variability in 24-hour ambulatory BP recordings added Ͻ1% to the prediction of a cardiovascular event. Sensitivity analyses considering ethnicity, sex, age, previous cardiovascular disease, antihypertensive treatment, number of BP readings per recording, or the night:day BP ratio were confirmatory. In conclusion, in a large population cohort, which provided sufficient statistical power, BP variability assessed from 24-hour ambulatory recordings did not contribute much to risk stratification over and beyond 24-hour BP. (Hypertension. 2010;55:1049-1057.)Key Words: blood pressure variability Ⅲ ambulatory blood pressure Ⅲ population science Ⅲ risk factors Ⅲ epidemiology A mbulatory blood pressure monitoring not only provides information on the blood pressure level but on the diurnal changes in blood pressure as well. Blood pressure variability includes both short-term and circadian components, which can be estimated by the SD of the blood pressure values over a defined period of the day or by the night:day blood pressure ratio, respectively. We recently reported in Ͼ7000 subjects recruited from 6 populations on the prognos- Although the aforementioned analyses shed light on the association between outcome and long-term blood pressure variability, the predictive value of short-term reading-toreading blood pressure variability remains uncertain. Possible limitations of previous studies were a lack of statistical power, 2-5 selection of specific groups of patients, 5-7 categorization of variability by arbitrary cutoff points, 2,4,7-9 and sole reliance on fatal end points. 10,11 Moreover, various parameters can capture short-term b...

ABP is superior to CBP in predicting cardiovascular events, but not total and noncardiovascular mortality. Cardiovascular risk gradually increases from normotension over white-coat and masked hypertension to sustained hypertension.

Nighttime blood pressure appears to convey additional risk information about CHF beyond office-measured blood pressure and other established risk factors for CHF. The clinical value of this association remains to be established in future studies.

INH predicts cardiovascular outcome in patients who are normotensive on office or on ambulatory daytime BP measurement.