Background and Purpose: The SWIFT PRIME trial demonstrated superior outcomes in patients presenting with disabling acute ischemic stroke (AIS) who underwent endovascular therapy vs. intravenous tissue plasminogen activator (t-PA) alone. We sought to understand the relationship between functional independence and time to reperfusion in study patients assigned to thombectomy.
Methods: SWIFT PRIME is a global, multi-center, prospective, randomized, open, blinded endpoint study comparing functional outcomes in AIS subjects treated with either IV t-PA alone or IV t-PA in combination with Solitaire stent retriever device. Among patients in whom substantial reperfusion (TICI 2b/3) was achieved, we analyzed the effect onindependent outcome (mRS 0-2) of time from stroke onset to reperfusion (OTR) and from qualifying imaging to reperfusion
Results: Among 83 patients undergoing thrombectomy, substantial reperfusion was achieved in 73 (88%). A marked effect of OTR was noted (Figure 1A). The rate of functional independence was 87% if reperfusion was achieved 150 minutes from symptoms onset. The absolute rate of good outcomes decreased by 10% over the next 60 minutes of delay in OTR and by 15% with every 60 minute delay there-after. Faster post-arrival workflow speed improved outcomes among patients presenting directly to study hospitals (Figure 1B).
Conclusions: Speed of reperfusion is a dominant determinant of functional outcome among patients treated with stent retrievers. In the early period after, every 6 minute delay in reperfusion causes 1 more out of 100 treated patients to not achieve functional independence.