Impact Of Blood Pressure Variability On Acute Ischemic Stroke Outcomes After Thrombolysis

Objective:The present study investigates impacts of hour-to-hour blood pressure (BP) variability on severe hemorrhagic transformation (HT), reperfusion and long-term outcome after intravenous thrombolysis (IVT).Methods:We analyzed hour-to-hour BP measurements from461patients with acute ischemic stroke and intravenous alteplase (0.9mg/kg) treatment. BP parameters were characterized by baseline, mean and BP variability parameters including maximum (max), minimum (min), standard deviation (SD), successive variation (SV), SV rise, SV drop and maximum of rise and drop values of adjacent measurements (SVmaxrise and SVmaxdrop, receptively). HT was classified as hemorrhagic infarction (HI) or parenchymal hematoma (PH) and symptomatic intracerebral hemorrhage (sICH) was defined as HT with worsening of the National Institute of Health Stroke Scale score by>4points or leading to death. Reperfusion was defined as>50%reduction in Tmax>6seconds perfusion lesion volume from acute to subacute scans. Unfavorable outcome was defined as modified Rankin Scale (mRS) score of2to6at3months.Result:We observed HT in142(30.8%), PH in43(9.3%) and sICH in12(2.6%) patients.96patients finished baseline and subacute perfusion scans. We observed reperfusion in57(59.4%) patients. During the0-to-24h BP course, only SBP variability parameters were positively significantly associated with PH/sICH. OR (95%CI) per10mm Hg (or10%for SD, SV) on PH and sICH were as follow:SD,1.994(1.05-3.78),4.538(1.83-11.23); SV,2.322(1.09-4.93),6.117(2.00-18.71), receptively. Most SBP parameters were significantly associated with long-term clinical outcomes:mean,1.344(1.15-1.57); max,1.266(1.12-1.42); min,1.196(1.02-1.40); max-min,1.209(1.05-1.39); SD,1.882(1.06-3.33); SV,3.998(2.20-7.26); SVmaxrise,1.618(1,29-7.26); SVmindrop,1.389(1.13-1.69). Only SBP SVrise during the first6hours after IVT was associated with reperfusion:SVrise,0.922(0.86-0.99).Conclusion:SBP variability during the first24hours after IVT was positively associated with severe HTs (PH and sICH), which highlights the potential predictability to severe HTs. SBP average and variability both predicted long-term outcomes. However, only SBP SVrise during the first6hours was negatively associated with reperfusion.