1373 Transcranial Doppler-Estimated Arterial Pressure Gradient is Associated With Delayed Cerebral Infarction and Subarachnoid Hemorrhage

INTRODUCTION: The application of pulsatility index (PI) in monitoring subarachnoid hemorrhage (SAH) patients using transcranial Doppler (TCD) remains uncertain. Recognizing that arterial pressure gradient (APG) can be estimated using blood pressure and PI, we aimed to investigate the potential significance of TCD-derived APG. METHODS: Among 186 SAH patients, we recorded the mean blood flow velocity (MFV) and PI values from the middle cerebral artery, along with corresponding blood pressures. Using a previously reported mathematical model, we estimated APG by dividing pulse pressure by PI. We evaluated the occurrence of delayed cerebral infarction (DCI) and assessed functional outcomes at discharge and 90 days post-SAH. RESULTS: A significant correlation was observed between APG and MFV (B=0.412, 95% CI 0.381-0.444, p<0.001). The occurrence of DCI affected the slope (B=0.072, 95% CI 0.009-0.135, p<0.001) of the MFV-APG correlation, resulting in higher APG values when the MFV was the same. Elevated APG was associated with DCI (OR 1.058, 95% CI 1.026-1.090, p<0.001), unfavorable functional outcome at discharge (OR 1.041, 95% CI 1.013-1.070, p=0.004) and at 90 days (OR 1.032, 95% CI 1.010-1.071, p=0.008). MFV values were associated with vasospasms but did not demonstrate any significant associations with DCI or functional outcome. CONCLUSIONS: Higher APG values were associated with DCI and unfavorable functional outcomes. TCD-derived APG values may provide prognostication value in the comprehensive monitoring of SAH patients.