Comparative Safety and Efficacy of Modified TICI 2b and TICI 3 Reperfusion in Acute Ischemic Strokes Treated With Mechanical Thrombectomy

BACKGROUND Mechanical thrombectomy (MT) is the current standard of care for acute ischemic stroke (AIS) patients with emergent large-vessel occlusions (ELVO). Successful reperfusion of ELVO is traditionally defined by modified Thrombolysis in Cerebral Infarction (mTICI) grades of 2b or 3. OBJECTIVE To evaluate the comparative safety and efficacy of mTICI 2b and mTICI 3 reperfusion in AIS patients treated with MT. METHODS Consecutive ELVO patients who underwent MT at 6 high-volume centers were included in this analysis. Standard safety (3-mo mortality, symptomatic intracranial hemorrhage [sICH]) and efficacy (absolute and relative reduction in NIHSS-scores during hospitalization, functional-improvement [shift analysis in mRS-scores], and functional-independence [mRS-scores of 0-2] at 3-mo) were compared between patients who had mTICI 2b and mTICI 3 reperfusion post MT. RESULTS A total of 416 ELVO patients achieved successful reperfusion with mTICI 2b (n = 216) and mTICI 3 (n = 200) following MT. The mTICI 3 group had significantly (P < .05) greater absolute (11 vs 9 points) and relative (77% vs 63%) reduction in NIHSS-scores during hospitalization, lower sICH (6% vs 12%), and higher 3-mo functional-independence (55% vs 44%) rates. Successful reperfusion with mTICI 3 was independently (P < .05) associated with greater absolute and relative reduction in NIHSS-scores during hospitalization as well as higher odds of 3-mo functional improvement (common odds ratios: 1.67; 95% confidence interval: 1.10-2.56) and functional independence (odds ratio: 2.08; 95% confidence interval: 1.22-3.53) in multivariable regression models adjusting for confounders. CONCLUSION Successful reperfusion with mTICI 3 was associated with greater neurological improvement during hospitalization and better 3-mo functional outcomes in comparison to mTICI 2b reperfusion.