Morning Blood Pressure Surge, Dipping, and Risk of Coronary Events in Elderly Treated Hypertensive Patients

Abstract

Background: The independent prognostic significance of morning surge (MS) of blood pressure (BP) is not yet clear. We investigated the association between MS of systolic BP and risk of coronary events in elderly treated hypertensive patients.

Methods: The occurrence of coronary events was evaluated in 1,191 elderly treated hypertensive patients (age range 60-90 years). Subjects were divided according to tertiles of MS of systolic BP of the population as a whole, by dipping status and by group-specific tertiles of MS of systolic BP in dippers and nondippers.

Results: During the follow-up (9.1 ± 4.9 years, range 0.4-20 years), 120 coronary events occurred. In the population as a whole, coronary event risk was not significantly associated with tertiles of MS of systolic BP, whereas nondippers were at higher risk than dippers. When nondippers and dippers were analyzed separately, by group-specific tertiles of MS of systolic BP, coronary event risk was associated with MS of systolic BP in dippers but not in nondippers. After adjustment for various covariates, Cox regression analysis showed that dippers in the third tertile (>23 mm Hg) of MS of systolic BP (hazard ratio 1.912, 95% confidence interval 1.048-3.488, P = 0.03) and nondippers (hazard ratio 1.739, 95% confidence interval 1.074-2.815, P = 0.02) were at higher coronary event risk than dippers with MS of systolic BP <23 mm Hg .

Conclusions: In elderly treated hypertensive patients, high MS of systolic BP predicts coronary events in dippers but not in nondippers. Nondippers, however, show higher risk of coronary events independently of MS in systolic BP.

Keywords: ambulatory blood pressure; blood pressure; coronary events; dippers; hypertension; morning surge; nondippers..