Immediate Recanalization of Large‐Vessel Occlusions by Tissue Plasminogen Activator Occurs in 28% of Patients Treated in a Mobile Stroke Unit

Abstract

Background Recanalization of cerebral large‐vessel occlusions (LVOs) by intravenous thrombolysis is infrequent but has been relatively unexplored with ultraearly treatment. We evaluated prehospital treatment with tissue plasminogen activator (tPA) in a mobile stroke unit to explore the recanalization rate in patients with LVOs and its effect on early clinical improvement and long‐term disability. Methods Prospectively collected data were analyzed from Houston mobile stroke unit patients who were treated with tPA and had LVOs identified by either hyperdense arteries on computed tomography or arterial occlusion on computed tomography angiography while on board the mobile stroke unit. The primary outcome was immediate recanalization (IRC), categorized as resolution of LVO on repeat vascular imaging in the emergency department (ED) or on emergent angiography. The secondary outcome was change in National Institutes of Health Stroke Scale from baseline and modified Rankin score at 90 days. Results Sixty‐nine patients with anterior or posterior circulation LVOs were enrolled; the median time from last known normal to tPA bolus was 64.0 minutes (interquartile range, 52.0–89.0). Nineteen patients (28%) had IRC, with 11 based on computed tomography angiography on ED arrival and 8 based on first run of emergent angiography. Median time from tPA bolus to documentation of IRC was 61.0 minutes (interquartile range, 42.0–111.0). IRC was associated with improvement in median National Institutes of Health Stroke Scale from baseline (17.0 [14.0–22.0]) to ED arrival (10.0 [5.5–16.5]) and to 24 hours (4.0 [0.5–10.5]). Of the non‐IRC patients, 41 had recanalization after endovascular thrombectomy and 9 did not receive recanalization. The IRC group, earlier last known normal to tPA bolus, greater baseline National Institutes of Health Stroke Scale, and M1 and M2 middle cerebral artery occlusion locations were independently associated with greater improvement in National Institutes of Health Stroke Scale from baseline to ED arrival. The 90‐day modified Rankin score distribution was best in the IRC group, followed by the delayed recanalization group, and both had significantly less disability than the no recanalization group ( P =0.002). Conclusions Recanalization by ED arrival occured in 28% of patients with LVO who received tPA treatment in a mobile stroke unit and results in early clinical improvement and less disability at 90 days.

Tenecteplase Improves Reperfusion across Time in Large Vessel Stroke

“…Achieving early reperfusion in an acute ischemic stroke strongly influences clinical outcomes. [1][2][3][4] In large vessel occlusion (LVO) patients treated with intravenous alteplase, the reported rates of thrombolytic agent-induced reperfusion prior to endovascular therapy ranges from 10 to 30%. [5][6][7][8] Alteplaseinduced reperfusion is associated with several factors, including occlusion site, thrombus permeability, and the time from thrombolytic to subsequent imaging assessment.…”

“…Achieving early reperfusion in an acute ischemic stroke strongly influences clinical outcomes 1–4 . In large vessel occlusion (LVO) patients treated with intravenous alteplase, the reported rates of thrombolytic agent‐induced reperfusion prior to endovascular therapy ranges from 10 to 30% 5–8 .…”

Intravenous Thrombolysis for Acute Ischemic Stroke

“…Several studies have examined outcomes in patients with large vessel occlusions presenting directly to the endovascular center emergency department who were randomly assigned to receive rtPA or not, prior to endovascular thrombectomy, with conflicting results 42-44 . While rtPA is relatively ineffective in dissolving a large vessel occlusion, it can do so in 10% to 30% of cases, 45 particularly if administered in the first hour after last time known well and given 30 to 60 minutes to work. A recent meta-analysis of patients presenting to nonendovascular thrombectomy centers with large vessel occlusions showed that outcomes were better if rtPA was given prior to transfer to the endovascular center than if it was skipped 46 .…”

Mobile Stroke Units in Acute Ischemic Stroke: A Comprehensive Systematic Review and Meta-Analysis of 5 “T Letter” Domains

“…I ntravenous thrombolysis (IVT) is one of the most effective acute ischemic stroke (AIS) treatments, yet it is delivered only to 2-5% of patients with AIS, due to delayed hospital presentation. 1 Moreover, nearly 30% of patients with AIS get recanalization after the tissue plasminogen activator (tPA) administration, particularly patients with large-vessel occlusion stroke, 2,3 raising the importance of not only the timely IVT administration but also the ability to recognize and triage large-vessel occlusion stroke cases to comprehensive stroke centers (CSCs). 1 Hence, the mobile stroke unit (MSU) was proposed as the "myriad-win" solution accordingly, for its ability to diagnose AIS, establish IVT eligibility, increase the rate of timely IVT administration and even speed administration into the golden hour (the first 60 minutes after symptom onset), [4][5][6] and promptly recognize and transport patients with large-vessel occlusion stroke to CSCs.…”