Time to Reset the Definition of Successful Revascularization in Endovascular Treatment of Acute Ischemic Stroke.

BACKGROUND: A 2013 consensus statement recommended the use of the modified Treatment In Cerebral Ischemia (mTICI) scale to evaluate angiographic revascularization after endovascular treatment (EVT) of acute ischemic stroke due to its higher inter-rater agreement and capacity of clinical outcome prediction. The current definition of successful revascularization includes the achievement of grades mTICI 2b or 3. However, mTICI 2b grade encompasses a large heterogeneity of revascularization states, and prior studies suggested that the magnitude of benefit derived from mTICI 2b and mTICI 3 does not seem to be equivalent. In a way to restrain the referred heterogeneity, Goyal et al. [J Neurointerv Surg 2014; 6: 83-86] proposed a revised mTICI scale that includes a 2c grade (rTICI).

METHODS: Retrospective analysis of prospectively collected data from consecutive cases of EVT for anterior circulation large-vessel occlusion, performed between January 2015 and July 2017. Patients with mTICI 2b or 3 grades were reclassified according to the rTICI scale, and the outcomes between the 3 revascularization grades (rTICI 2b, 2c, 3) compared.

RESULTS: Our study population of 226 patients (64 rTICI 2b, 30 rTICI 2c, 132 rTICI 3) has a mean age of 71 years, 48.2% males, median baseline NIHSS of 16 (13-19) and ASPECTS of 8 (7-9). The 3 revascularization grades are represented by homogeneous populations. Logistic regression analysis showed statistically significant higher rates of functional independence at 3 months (65.9 vs. 50.0%; adjusted OR 0.39, 95% CI 0.18-0.86), with lower rates of mortality (8.3 vs. 15.6%; adjusted OR 3.54, 95% CI 1.14-10.97) and intracranial hemorrhage (ICH) in rTICI 3 than 2b groups. When comparing rTICI 3 with 2c groups, there were only statistically significant differences in the total ICH rate (8.3 vs. 26.7%; adjusted OR 7.08, 95% CI 1.80-27.82) but not in symptomatic ICH.

CONCLUSIONS: These results corroborate the scarce prior findings suggesting that patients with rTICI 2c grade should be reported separately, since they have similar outcomes to rTICI 3, and better than rTICI 2b patients. Therefore, we suggest resetting the angiographic revascularization endpoint to perfect revascularization (rTICI 2c or 3 grades), a target that neurointerventionalists should strive to achieve.