Nighttime Systolic Blood Pressure Determined by Pulse Transit Time Predicts Cardiac Events in Patients With Heart Failure.

Background: The optimal systolic blood pressure (SBP) target for heart failure (HF) patients has not been established. Although the association between daytime SBP and prognosis has been reported in patients with HF, the prognostic impact of nighttime SBP remains unclear.

Methods: We conducted continuous nighttime SBP measurements noninvasively using pulse transit time in 366 patients with HF (median age, 72 years; male sex, 195), and followed up for cardiac events (HF hospitalization or cardiac death). Average values of nighttime pulse transit time -based SBP were used in the present study. The patients were divided into tertile groups based on nighttime pulse transit time-based SBP: high-SBP group (median SBP, 136 mm Hg; n=122), middle-SBP group (median SBP, 117 mm Hg; n=122), and low-SBP group (median SBP, 100 mm Hg; n=122).

Results: During a median follow-up period of 1083 days after nighttime pulse transit time-based SBP measurement, 71 patients experienced a cardiac event. Kaplan-Meier analysis showed the highest incidence of cardiac events in the low-SBP group. Multivariate Cox proportional hazard analysis also showed that the lowest SBP tertile was associated with a higher risk of cardiac events compared with the highest SBP tertile as reference (hazard ratio, 2.100 [95% CI, 1.121-3.933]; P=0.021).

Conclusions: Low nighttime SBP was associated with an increased cardiac event rate in patients with HF.