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

BACKGROUND: To evaluate the impact of daytime, nighttime, and nocturnal blood pressures (BPs) fall on heart failure (HF). METHODS: We analyzed data from five cohorts including 15,526 treated hypertensive patients, experiencing 625 HF events, by study-level meta-analysis. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for 1SD 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 BP was 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 the outcome. Heterogeneity across cohorts was explained by BP, sex, and follow-up duration. In sensitivity analyses, for daytime and nighttime BPs, no study had a 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.