Prehospital Blood Pressure and Clinical and Radiological Outcomes in Acute Spontaneous Intracerebral Hemorrhage

Abstract

Background: High blood pressure (BP) is associated with poor outcome in acute spontaneous intracerebral hemorrhage. Little is known about the predictive value of prehospital BP in intracerebral hemorrhage. We aimed to investigate the relationship between prehospital BP and clinical and radiological outcomes.

Methods: This is a retrospective, hospital-based study of all adult intracerebral hemorrhage patients admitted within 24 hours of symptom onset to a large primary stroke centre during 2012 to 2019. The first prehospital and on-admission BP were recorded as systolic BP, diastolic BP, mean arterial pressure, and pulse pressure. The absolute differences between prehospital and on-admission BP were calculated (BP_change). Primary outcomes were in-hospital death, early neurological deterioration, and hematoma expansion. Associations between prehospital BP, BP_change, and outcomes were explored by regression with adjustment for relevant confounders.

Results: We included 426 patients aged median 76 (interquartile range 67-85) years and 203 (48%) were female. Median prehospital systolic BP was 179 (interquartile range 158-197) and diastolic BP was 100 (interquartile range 86-112) mm Hg. In-hospital death occurred in 121/426 (28%), early neurological deterioration in 107/295 (36%), and hematoma expansion in 50/185 (27%) patients. There were linear associations between 5 mm Hg increment of prehospital systolic BP (odds ratio 1.06, [95% CI, 1.01-1.12]) and mean arterial pressure (odds ratio 1.08, [95% CI, 1.01-1.15]) and in-hospital death, and between 5 mm Hg increment of prehospital diastolic BP (odds ratio 1.10, [95% CI, 1.00-1.21]) and mean arterial pressure (odds ratio 1.09, [95% CI, 1.00-1.18]) and hematoma expansion. There was a nonlinear association between prehospital systolic BP and in-hospital death. No consistent associations between prehospital BP_change and outcomes were found.

Conclusions: In patients with acute intracerebral hemorrhage, elevated prehospital BP parameters were associated with in-hospital death and hematoma expansion. Changes in prehospital BP were not consistently associated with outcome. A possible U-shaped association between prehospital BP and in-hospital death needs further investigation.

Keywords: blood pressure; intracerebral hemorrhage; prehospital.