Abstract 1122‐000084: Does Intravenous Thrombolysis Promote Delayed Reperfusion After Incomplete Mechanical Thrombectomy?

Introduction : The value of intravenous thrombolysis (IVT) in patients eligible for mechanical thrombectomy (MT) remains unclear. We hypothesized that pre‐treatment with and/or ongoing IVT may facilitate reperfusion of distal vessel occlusion after incomplete MT. We evaluated this potential association using follow‐up perfusion imaging. Methods : Retrospective observational analysis of our institution`s stroke registry included patients with incomplete reperfusion after MT, admitted between February 1, 2015 and December 8, 2020. Delayed reperfusion (DR) was defined as the absence of a persistent perfusion deficit on contrast‐enhanced perfusion imaging ⁓24h±12h after the intervention. The association between baseline parameters and the occurrence of DR was evaluated using a logistic regression analyses. To account for possible time‐dependent associations of IVT with DR, additional stratification sets were made based on different time windows between IVT start time and final angiography runs. Results : Among the 378 included patients (median age 73.5, 50.8% female), DR occurred in 226 (59.8%). Atrial fibrillation (aOR 2.53 [95% CI 1.34 ‐ 4.90]), eTICI score (aOR 3.79 [95% CI 2.71 ‐ 5.48] per TICI grade increase), and intervention‐to‐follow‐up time (aOR 1.08 [95% CI 1.04 ‐ 1.13] per hour delay) were associated with DR. Dichotomized IVT strata showed no association with DR (aOR 0.75 [95% CI 0.42 ‐ 1.33]), whereas shorter intervals between IVT start and end of the procedure showed a borderline significant association with DR (OR 2.24 [95% CI 0.98 ‐ 5.43, and OR 2.07 [95% 1.06 – 4.31], for 80 and 100 minutes respectively). Patients with DR had higher rates of functional independence (modified Rankin scale 0–2 at 90 days, DR: 63.3% vs PPD: 38.8%; p<0.01) and longer survival time (at 3 years, DR: 69.2% vs PPD: 45.8%; p = 0.001). Conclusions : There is weak evidence that IVT may favor DR after incomplete MT if the time interval between IVT administration and end of the procedure is short. In general, perfusion follow‐up imaging may constitute a suitable surrogate parameter for evaluating medical rescue strategies after incomplete MT, because a considerable proportion of patients do not experience DR, and there seems to be a close correlation with clinical outcomes.