Introduction: Decisions to transport patients from primary to comprehensive stroke centre would be influenced by info on likelihood/timing of spontaneous or IV tPA recanalization (recan). We examined recan rates by time for a wide range of occlusion sites in the INTERRSeCT multicenter prospective cohort study.
Methods: Acute stroke patients consented/enrolled at 12 centers/5 countries if intracranial occlusion present on baseline CTA; eGFR≥60 ml/min. CTA was repeated 2-6 hrs later for recan unless patient taken for EVT (first run of angio used instead). Primary outcome was successful recan (rAOL scale score 2b/3) interpreted by central core lab.
Results: 619 patients enrolled, 81.6% received IV tPA. 59.9% recan by follow-up CTA and 40.1% by first run angio. Median baseline NIHSS 14 (IQR 11); mean age 70.1 yrs (SD 13); median onset to baseline CTA 115 mins (IQR 108). Recan assessment imaging median 162 mins (IQR 198) from IV tPA bolus or baseline CTA (if no IV tPA). Successful recan (rAOL 2b-3) rates comparing baseline to repeat imaging shown in Figure 1a (IV tPA red; no IV tPA blue). IV tPA had much higher recan than non-IV tPA group (30.5% vs 11%, p<0.0001). Successful recan rates by occlusion site and by time from IV tPA bolus shown in Figure 1b. Site of occlusion, tPA administration, time from tPA to recan assessment and baseline residual flow were the only independent predictors of recan (all p<0.0001). Distal M1 MCA had highest recan [RR 4.12; 95% CI 1.91-8.86 vs. ICA].
Conclusions: Early recan rates were low across all occlusion sites. Beyond 6 hrs post tPA, recan rates approached EVT levels except for ICA. Imaging factors such as residual flow may further refine transport/triage decisions.