Association Between 24-Hour Systolic Blood Pressure Time in Target Range and Mortality

Abstract

Background: Time in target range (TTR) reflects the proportion of time blood pressure (BP) remains within a defined range, integrating BP variability and control. We examined associations of systolic BP (SBP) TTR during ambulatory BP monitoring with cardiovascular and all-cause mortalities.

Methods: Patients from the Spanish Ambulatory BP Monitoring Registry who were receiving antihypertensive medications or who had sustained or masked hypertension without treatment, defined by office BP ≥140/90 mmHg and 24-hour BP ≥130/80 mmHg, were included. TTR was estimated by linear interpolation between consecutive SBP recordings obtained from ambulatory BP monitoring and expressed as the proportion of time SBP remained within 120 to 134 mm Hg during daytime and 110 to 119 mm Hg during nighttime, from which 24-hour TTR was derived. Associations with mortality were assessed by Cox regression adjusted for demographic and clinical variables.

Results: A total of 48 687 patients (46% women) were analyzed. Over a median follow-up of 9.7 years, 6502 deaths occurred, including 2185 cardiovascular deaths. Higher 24-hour TTR was associated with lower all-cause mortality (hazard ratio, 0.83 per 1-SD increment [95% CI, 0.80-0.85]). Similarly, higher 24-hour TTR was associated with lower cardiovascular mortality (hazard ratio, 0.80 per 1-SD increment [95% CI, 0.76-0.84]). Both associations remained significant after adjusting for the mean 24-hour SBP and SBP variability.

Conclusions: Higher 24-hour SBP TTR derived from ambulatory BP monitoring was independently associated with lower all-cause and cardiovascular mortalities.