Heidenhain (Slovakia)

Background: Recent stroke clinical trials demonstrate the profound impact of collaterals, yet time constraints are often cited as rationale for not evaluating or imaging collaterals prior to endovascular therapy (EVT). We examined the role of collaterals on patient outcomes in a large registry of EVT, analyzing actual time required to obtain such data before treatment of various occlusion sites and monitoring for potential harm. Methods: ENDOSTROKE is an industry-independent, centrally-monitored multicenter registry evaluating EVT in routine clinical practice. Central reading of angiographic data blinded to clinical information was performed by the core lab in 695 patients assessing TICI scores, ASITN collateral grade and detailed procedural time metrics. Results: 75% had anterior circulation strokes (including 270 proximal MCA, 106 ICAT, 90 cICA occlusions) and 25% posterior circulation strokes (including 148 basilar artery occlusions). Assessment of ASITN collateral grade was possible in 511 (73%) of patients; in 184 (27%) collateral status was not obtained prior to therapeutic intervention. Median time from initial angiography and first evidence of TICI 2A reperfusion was only one minute longer in patients with available ASITN scores than in those without (38 min (23, 61) vs. 37 (22, 55), p=0.552) and time-differences were even smaller in anterior circulation strokes (median time 37 min in both groups). In vertebrobasilar occlusion, this time metric was 5 minutes longer in those with available ASITN scores (39 min (24, 39)) than in those without (34 min (23, 52), p=0.357). Of those with ASITN available, patients with grade 3-4 had much better outcomes (48% 0-2 90-day mRS) than patients with grade 0-2 (30%, p<0.0001). No excess in complication rate (i.e. dissection, thrombemboli) was noted in the cohort with available ASITN. Conclusions: Collaterals have a dramatic association with clinical outcomes in the largest endovascular study to date. In routine practice, EVT outcomes across various occlusion sites are strongly influenced by collateral grade. Negligible time of only a few minutes is typically required to obtain such essential data prior to treatment with no cost of incremental harm.