Lower in-hospital nighttime systolic blood pressure is associated with heart failure Rehospitalization in heart failure with reduced ejection fraction

BACKGROUND: The prognostic significance of nighttime blood pressure (BP) in hospitalized patients with heart failure with reduced ejection fraction (HFrEF) remains uncertain. We investigated whether standardized in-hospital nighttime systolic BP (SBP) measured before discharge predicts post-discharge outcomes beyond casual SBP. METHODS: This single-center observational study included 235 symptomatic inpatients with HFrEF (left ventricular ejection fraction ≤40%; New York Heart Association class II-IV) admitted between 2013 and 2017. Nighttime BP was measured hourly from 23:00 to 06:00 in the supine position using a programmable oscillometric upper-arm device, and mean nighttime SBP was calculated from at least 6 readings. Casual SBP was the mean of 2 seated morning measurements obtained on the same day. The primary endpoint was heart failure (HF) rehospitalization analyzed using Fine-Gray competing-risk models with all-cause death as the competing event. All-cause mortality was analyzed using Cox models. RESULTS: During a median follow-up of 3.7 years, 77 patients (32.8%) had HF rehospitalization and 35 (14.9%) died. Mean nighttime SBP per 10-mmHg increase was inversely associated with HF rehospitalization after adjustment for age, sex, estimated glomerular filtration rate, log-transformed B-type natriuretic peptide, and left ventricular ejection fraction [subdistribution hazard ratio (SHR) 0.85, 95% confidence interval (CI) 0.75-0.95; p = 0.006]. The association remained significant after additional adjustment for casual SBP (SHR 0.85, 95% CI 0.75-0.98; p = 0.023), whereas casual SBP was not predictive. Adjustment for loop diuretic use attenuated the association. Additional Fine-Gray analyses showed similar results when cardiovascular death was treated as the competing event and after additional adjustment for ischemic heart disease. Nighttime SBP was not significantly associated with all-cause mortality. CONCLUSIONS: Lower in-hospital nighttime SBP before discharge was associated with a higher risk of subsequent HF rehospitalization in HFrEF, providing prognostic information beyond casual SBP.