Abstract P488: The Impact of First Pass Effect on Acute Ischemic Stroke Clinical Outcomes: Why We Need to Continue to Improve Mechanical Thrombectomy?

Abstract

Background: Mechanical thrombectomy (MT) has significantly improved outcomes of acute ischemic stroke (AIS) patients due to large vessel occlusion (LVO). The first-pass effect (FPE), defined as achieving complete reperfusion (mTICI3/2c) with a single pass, was reported to be associated with higher functional independence rates following EVT and has been emphasized as an important procedural target. We compared MT outcomes in patients who achieved FPE to those who did not in a real world large database. Method: A retrospective analysis of LVO pts who underwent MT from a single center prospectively collected database. Patients were stratified into those who achieved FPE and non-FPE. The primary outcome (discharge and 90 day mRS 0-2) and safety (sICH, mortality and neuro-worsening) were compared between the two groups. Results: Of 580 pts, 261 (45%) achieved FPE and 319 (55%) were non-FPE. Mean age was (70 vs 71, p=0.051) and mean initial NIHSS (16 vs 17, p=0.23) and IV tPA rates (37% bs 36%, p=0.9) were similar between the two groups. Other baseline characteristics were similar. Non-FPE pts required more stenting (15% vs 25%, p=0.003), and angioplasty (19% vs 29%, p=0.01). The FPE group had significantly more instances of discharge (33% vs 17%, p<0.001), and 90-day mRS score 0-2 (29% vs 20%, p<0.001), respectively. Additionally, the FPE group had a significant lower mean discharge NIHSS score (12 vs 17, p<0.001). FPE group had better safety outcomes with lower mortality (14.2% vs 21.6%, p=0.03), sICH (5.7% vs 13.5, p=0.004), and neurological worsening (71.3% vs 78.4%, p=0.02), compared to the non-FPE group. Conclusion: Patients with first pass complete or near complete reperfusion with MT had higher functional independence rates, reduced mortality, symptomatic hemorrhage and neurological worsening. Improvement in MT devices and techniques is vital to increase first pass effect and improve clinical outcomes.