Beat‐to‐Beat Blood Pressure Variability Within 24 Hours of Ischemic Stroke Onset: A Potential Predictor of Functional Prognosis

Abstract

Background Beat‐to‐beat blood pressure variability (BPV) is based on each heartbeat and represents a dynamic equilibrium process modulated by artery and cardiac involvement of pressure‐receptive reflexes. To date, there remains a lack of prospective studies illustrating the clinical value of beat‐to‐beat BPV within 24 hours of acute ischemic stroke onset. Methods and Results This study prospectively monitored beat‐to‐beat blood pressure and heart rate in patients with acute ischemic stroke within 24 hours of onset using a noninvasive plethysmograph and calculated beat‐to‐beat BPV, heart rate variability, and the cross‐correlation baroreflex sensitivity. A modified Rankin Scale score of ≥2 at 90 days was defined as an unfavorable prognosis. Multivariate logistic regression was performed, and the nomogram model was developed by adding the beat‐to‐beat BPV to the traditional model for predicting prognosis. Beat‐to‐beat BPV increased significantly in the unfavorable outcome group ( P <0.05) compared with that in the favorable outcome group, whereas no difference was observed in beat‐to‐beat heart rate variability and cross‐correlation baroreflex sensitivity between both groups ( P >0.05). Furthermore, beat‐to‐beat BPV within 24 hours of acute ischemic stroke onset was independently associated with unfavorable outcome at 90 days ( P <0.005). The addition of beat‐to‐beat BPV to the traditional model for predicting prognosis enhanced the area under the receiver operating characteristic curve from 0.816 to 0.830. Conclusions Increased beat‐to‐beat BPV within 24 hours of acute ischemic stroke onset was independently associated with a poor prognosis at 90 days and may be a potential predictor for discriminating unfavorable prognosis.