Systolic Blood Pressure Time in Target Range and Incident Atrial Fibrillation in Patients with Hypertension: Insights from the SPRINT Trial

Abstract

BACKGROUND: Systolic blood pressure (SBP) time in target range (TTR) indicates the mean value, exposure time, and variability in blood pressure over time. The prognostic value of SBP TTR for incident atrial fibrillation (AF) in patients with hypertension is unclear. METHODS: We performed a post hoc analysis of SPRINT (Systolic Blood Pressure Intervention Trial), a randomized controlled trial comparing intensive (<120 mm Hg) and standard (<140 mm Hg) SBP interventions in participants with hypertension. SBP target ranges for intensive and standard arms were defined as 110 to 130 and 120 to 140 mm Hg, respectively. TTR was calculated by linear interpolation method using SBP from months 0 to 3. We used Cox proportional regression models to assess the association of SBP TTR with incident AF. RESULTS: Among 7939 participants included in this analysis, 187 incident AF cases occurred during follow-up. After multivariable adjustment, a 10% increase in SBP TTR was independently associated with a 7% lower risk of incident AF (hazard ratio, 0.93 [95% CI, 0.88-0.97]; P=0.003). The restricted spline curve depicted a linear and inverse relationship between SBP TTR and incident AF. Sensitivity analyses generated consistent results when calculating TTR over a longer period or setting target range as 110 to 140 mm Hg for the whole population. CONCLUSIONS: Higher SBP TTR independently predicts a lower risk of incident AF. Efforts to attain SBP within 110 to 140 mm Hg over time may be an effective strategy to prevent AF. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01206062.