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

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.