Objective: To investigate the multivariate-adjusted predictive value of systolic and diastolic blood pressures on conventional (CBP) and daytime (10–20 h) ambulatory (ABP) measurement.
Methods: We randomly recruited 7030 subjects (mean age 56.2 years; 44.8% women) from populations in Belgium, Denmark, Japan and Sweden. We constructed the International Database on Ambulatory blood pressure and Cardiovascular Outcomes.
Results: During follow-up (median = 9.5 years), 932 subjects died. Neither CBP nor ABP predicted total mortality, of which 60.9% was due to noncardiovascular causes. The incidence of fatal combined with nonfatal cardiovascular events amounted to 863 (228 deaths, 326 strokes and 309 cardiac events). In multivariate-adjusted continuous analyses, both CBP and ABP predicted cardiovascular, cerebrovascular, cardiac and coronary events. However, in fully-adjusted models, including both CBP and ABP, CBP lost its predictive value (P ≥ 0.052), whereas systolic and diastolic ABP retained their prognostic significance (P ≤ 0.007) with the exception of diastolic ABP as predictor of cardiac and coronary events (P ≥ 0.21). In adjusted categorical analyses, normotension was the referent group (CBP < 140/90 mmHg and ABP < 135/85 mmHg). Adjusted hazard ratios for all cardiovascular events were 1.22 [95% confidence interval (CI) = 0.96–1.53; P = 0.09] for white-coat hypertension (≥ 140/90 and < 135/85 mmHg); 1.62 (95% CI = 1.35–1.96; P < 0.0001) for masked hypertension (< 140/90 and ≥ 135/85 mmHg); and 1.80 (95% CI = 1.59–2.03; P < 0.0001) for sustained hypertension (≥ 140/90 and ≥ 135/85 mmHg).
Conclusions: 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.
aResearch Center for Prevention and Health, Copenhagen, Denmark
bTohoku University Graduate School of Pharmaceutical Sciences and Medicine, Sendai, Japan
cThe Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, Department of Cardiovascular Diseases, University of Leuven, Leuven, Belgium
dThe Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Sweden
eThe Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden
fThe Copenhagen University Hospital, Copenhagen, Denmark
Received 9 December, 2006
Revised 9 March, 2007
Accepted 4 April, 2007
Correspondence to Jan A. Staessen, Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, Department of Cardiovascular Diseases, University of Leuven, Campus Gasthuisberg, Herestraat 49, Box 702, B-3000 Leuven, Belgium Tel: +32 16 34 7104; fax: +32 16 34 7106; e-mail: email@example.com