Abstract P545: First Pass TICI 2b versus Multiple Passes TICI 3 for Acute Ischemic Stroke Patients: Is First Pass TICI 2b Enough?

Abstract

Background and Objective: Prompt and complete reperfusion with mechanical thrombectomy (MT) is essential to improve outcome in acute ischemic strokes (AIS) with large vessel occlusion (LVO). Recently, first-pass effect (FPE), defined as achieving complete reperfusion with a single pass, has been emphasized as a potentially important MT target. We aimed to compare outcomes between patients who achieve mTICI 2b with first pass to those with multiple devise passes (MDP) mTICI 3. Methods: From a single comprehensive stroke center database, we retrospectively grouped LVO pts treated with MT into those who achieved mTICI 2b after a single pass and mTICI 3 after MDP. Clinical outcome (discharge and 90-day mRS), discharge NIHSS and safety (sICH, neurological worsening, mortality) were compared between the two groups. Results: Of 186 pts included, 153 (82%) achieved mTICI 3 with MDP, and 33 (18%) had mTICI 2b after a single pass. Mean age (71 vs 69), NIHSS (17 vs 16, p=0.2) were similar between the two groups. Patients with a single pass mTICI 2b had numerically higher IV tPA administration (33% vs 46%, p=.16). There was no difference in other baseline characteristics. There was no significant difference in discharge (21% vs 24.2%, p=0.65) and 90-day mRS 0-2 (24% vs 24%, p=0.5), MDP mTICI 3 and single pass mTICI 2b, respectively. Also, there was no difference in discharge NIHSS score (13.6 vs 16.7, p=0.26), mortality (16.3% vs 18.2%, p=0.8) and sICH rates (7.8% vs 18.2%, p=0.095) or neurological worsening (76.5% vs 69.7%, p=1). Conclusion: Our results did not show a significant difference between mTICI 3 with multiple passes and mTICI 2b after a single pass. Future large studies are warranted to explore the possibility of extending the first pass effect to patients who achieve mTICI 2b with a single pass.