To investigate the impact of early blood pressure (BP) decrease on infarct volumes in acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) undergoing inter-hospital transfer.  

Optimal BP management during the early inter-hospital transfer period remains unclear and determining the effects of BP control in this hyper-acute period is vital. As a major component of cerebral perfusion, decreases in BP can potentially reduce the blood flow to the ischemic penumbra increasing the core infarct size.

All consecutive AIS patients with LVO involving the internal carotid artery or middle cerebral artery (M1 and M2) transferred from one network hospital to another for thrombectomy consideration between January 2019 and September 2020 were included.  BP recordings pre and during transfer, along with demographic and radiographic data were retrospectively collected. Infarct volume was defined as cerebral blood flow volume of <30% calculated using CT perfusion RAPID (IschemaView) software on arrival at the post-transfer hospital. For the purpose of our study, a decrease of >20% from the highest recorded systolic BP (SBP) during pre-transfer or transfer was regarded as a significant decrease.

Of the 25 patients (average age 66.1±15.6, average NIHSS 14.8±7.5) meeting inclusion criteria, 12 (48%) experienced a significant decrease in SBP prior to arrival at the post-transfer hospital. Among patients with a significant decrease in SBP, the average decrease was 59.3±21.0 mm Hg from a mean highest SBP of 167.8±32.9 mm Hg. In the multivariable regression analysis adjusting for age and baseline NIHSS, a significant decrease in SBP was independently associated with an increase in infarct volume (β=0.448, p=0.026).

In our study, a significant drop in SBP in AIS patients with LVO during inter-hospital transfers was observed in a large proportion of patients and was associated with larger core infarct volumes.