Prognostic value of reading-to-reading blood pressure variability over 24 hours in 8938 subjects from 11 populations.
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 (P<or=0.03) total (HR: 1.14) and cardiovascular (HR: 1.21) mortality and all types of fatal combined with nonfatal end points (HR: >or=1.07) with the exception of cardiac and coronary events (HR: <or=1.02; P>or=0.58). Higher systolic average real variability in 24-hour ambulatory BP recordings predicted (P<0.05) total (HR: 1.11) and cardiovascular (HR: 1.16) mortality and all fatal combined with nonfatal end points (HR: >or=1.07), with the exception of cardiac and coronary events (HR: <or=1.03; P>or=0.54). 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 <1% 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.
Hansen
Tine W
TW
Department of Clinical Physiology, Faculty of Health Sciences, Hvidovre University Hospital, Research Center for Prevention and Health, Copenhagen, Denmark.
Thijs
Lutgarde
L
Li
Yan
Y
Boggia
José
J
Kikuya
Masahiro
M
Björklund-Bodegård
Kristina
K
Richart
Tom
T
Ohkubo
Takayoshi
T
Jeppesen
Jørgen
J
Torp-Pedersen
Christian
C
Dolan
Eamon
E
Kuznetsova
Tatiana
T
Stolarz-Skrzypek
Katarzyna
K
Tikhonoff
Valérie
V
Malyutina
Sofia
S
Casiglia
Edoardo
E
Nikitin
Yuri
Y
Lind
Lars
L
Sandoya
Edgardo
E
Kawecka-Jaszcz
Kalina
K
Imai
Yutaka
Y
Wang
Jiguang
J
Ibsen
Hans
H
O'Brien
Eoin
E
Staessen
Jan A
JA
D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D011795:Surveys and Questionnaires