Association of initial imaging modality and futile recanalization after thrombectomy.

Meinel, Thomas Raphael; Kaesmacher, Johannes; Mosimann, Pascal John; Seiffge, David; Jung, Simon; Mordasini, Pasquale; Arnold, Marcel; Goeldlin, Martina; Hajdu, Steven D; Olivé-Gadea, Marta; Maegerlein, Christian; Costalat, Vincent; Pierot, Laurent; Schaafsma, Joanna D; Fischer, Urs; Gralla, Jan

OBJECTIVE To test the hypothesis that selection by initial imaging modality (MRI vs CT) is associated with rate of futile recanalizations (FR) after mechanical thrombectomy (MT), we assessed this association in a multicenter, retrospective observational registry (BEYOND-SWIFT, NCT03496064). METHODS In 2011 patients (49.7% female, median age 73 [61-81]) included between 2009 and 2017, we performed univariate and multivariate analyses regarding the occurrence of FR. FR were defined as 90 days modified Rankin Scale (mRS) 4-6 despite successful recanalization in patients selected by MRI (N = 690) and CT (N = 1,321) with a sensitivity analysis considering only patients with mRS 5-6 as futile. RESULTS MRI as compared to CT resulted in similar rates of subsequent MT (aOR 1.048, 95% CI 0.677-1.624). Rates of FR were as follows: 571/1,489 (38%) FR mRS 4-6 including 393/1,489 (26%) FR mRS 5-6. CT based selection was associated with increased rates of futile recanalizations compared to MRI (44% [41%-47%] vs 29% [25%-32%], p < 0.001; aOR 1.77 [95%-CI: 1.25-2.51]). These findings were robust in sensitivity analysis. MRI-selected patients had a delay of approximately 30 minutes in workflow metrics in real-world university comprehensive stroke centers. However, functional outcome and mortality were more favorable in patients selected by MRI compared to patients selected with CT. CONCLUSIONS CT-selection for MT was associated with an increased risk of futile recanalizations as compared to MR-selection. Efforts are still needed to shorten workflow delays in MRI patients. Further research is needed to clarify the role of the initial imaging modality on FR occurrence and to develop a reliable FR prediction algorithm.