Night-day blood pressure ratio and dipping pattern as predictors of death and cardiovascular events in hypertension

Our objective was to assess the prognostic significance of the night-time dipping pattern and the night-day blood pressure (BP) ratio for mortality and cardiovascular events in hypertensive patients without major cardiovascular disease at baseline. We performed a meta-analysis on individual data of 3468 patients from four prospective studies performed in Europe. Age of the subjects averaged 61+/-13 years; 45% were men and 61% were under antihypertensive treatment at the time of ambulatory BP monitoring. The night-day BP ratio and 24-h BP averaged, respectively, 0.907+/-0.085/0.866+/-0.095 and 138.1+/-16.4/82.3+/-11.0 mm Hg. Total follow-up time amounted to 23 164 patient-years. We used multivariable Cox regression analysis to assess the outcome of reverse dippers, non-dippers and extreme dippers vs dippers, and to assess the hazard ratios associated with 1 standard deviation higher night-day BP ratio. In comparison with dippers, and with adjustment for confounders and 24-h BP, the incidence of cardiovascular events was worse in reverse dippers (P<or=0.05), whereas mortality was lower in extreme dippers (P<or=0.01); outcome was similar in non-dippers and dippers. The systolic night-day BP ratio independently predicted all-cause mortality and cardiovascular events (P<or=0.001), which persisted after additional adjustment for 24-h BP (P