Impact of Daytime and Nighttime Blood Pressure and Nocturnal Blood Pressure Fall on Heart Failure Risk in Treated Hypertension.

Abstract

Background: To evaluate the impact of daytime, nighttime and nocturnal blood pressure (BP) fall on heart failure (HF).

Methods: We analyzed data of five cohorts including 15,526 treated hypertensive patients, experiencing 625 HF events, by study-level meta-analysis. The pooled hazard ratios (HR) and 95% confidence intervals (CI) for 1-SD increase in BP parameters or per group were calculated.

Results: When individually analyzed after adjustment for covariates, clinic systolic BP (SBP) (HR 1.20, 95% CI 1.01-1.43), daytime SBP (HR 1.34, 95% CI 1.06-1.70), nighttime SBP (HR 1.43, 95% CI 1.20-1.71), nighttime diastolic BP (DBP) (HR 1.26, 95% CI 1.05-1.52), % of nocturnal SBP fall (HR 0.81, 95% CI 0.75-0.88) and nondipping (HR 1.64, 95% CI 1.54-1.98) were associated with HF. If daytime or nighttime BPs were further adjusted for clinic BP results remained similar. When clinic, daytime and nighttime BPs were mutually adjusted, nighttime SBP (HR 1.43, 95% CI 1.27-1.61) and nighttime DBP (HR 1.37, 95% CI 1.14-1.64) remained associated with outcome. Heterogeneity across cohorts was explained by BP, sex and follow-up duration. In sensitivity analyses, for daytime and nighttime BP, no study had relevant influential effect on overall estimates. Looking for publication bias and adjusting for missing studies by Duval and Tweedie's method, clinic SBP lost significance but daytime SBP, and nighttime SBP and DBP remained significantly associated with HF.

Conclusions: daytime and nighttime BPs are stronger than clinic BP in predicting HF, nighttime BP is stronger than daytime BP and a reduced nocturnal BP fall is associated with outcome.