Abstract 172: Bridging Therapy versus Intravenous Thrombolysis in Minor Stroke With Large Vessel Occlusion. A French Multicentric Observational Study (MINOR-STROKE)

Abstract

Introduction: Whether bridging therapy (endovascular therapy [EVT] plus intravenous thrombolysis [IVT]) is superior to IVT alone in minor strokes with large vessel occlusion (LVO) is unknown. Methods: MINOR-STROKE was a multicentric retrospective cohort collecting data of IVT-treated minor strokes (NIHSS≤5) with LVO (ICA, M1 or M2; with central reading) treated with or without additional EVT in 45 French stroke units. Patients immediately intended for additional EVT -including those who eventually did not receive EVT- were analyzed in the bridging group, whereas patients initially intended for IVT alone -including those who eventually received rescue EVT- were analyzed in the IVT group. Propensity-score (inverse probability of treatment weighting) was used to reduce baseline between-groups differences. The primary outcome was excellent outcome defined as mRS 0-1 at 3 month. Results: Overall, 965 patients were included (237 and 728 in the bridging therapy and IVT groups, respectively). The distribution of all baseline clinical and radiological variables across the 2 groups were similar following propensity-score weighting. Compared with IVT alone, bridging therapy was not associated with better excellent outcome (OR=0.99; 95%CI 0.79-1.24; P =0.95), but was associated with higher risks of symptomatic intracranial haemorrhage (OR=2.39; 95%CI 1.51-3.80; P <0.001). However, occlusion site was a strong modifier of the effect of bridging therapy on excellent outcome (P interaction <0.0001), bridging therapy seeming beneficial in isolated ICA (OR=2.75; 95%CI 1.23 6.13; P =0.01) and proximal M1±ICA (OR=3.63; 95%CI 1.94-6.79; P <0.0001), neutral for distal M1±ICA (OR=0.96; 95%CI 0.63-1.48; P =0.87) but deleterious for M2±ICA (OR=0.54; 95%CI 0.38-0.75; P <0.001) occlusions. Bridging therapy was only associated with sICH in patients with M2 occlusions (OR=4.73; 95%CI 2.35-9.49; P <0.0001). Conclusion: Overall, we observed similar outcomes with bridging therapy or IVT alone in minor strokes with LVO. However, our data suggest benefit of bridging therapy in patients with ICA or proximal M1 occlusion and potential harm through sICH in patients with M2 occlusion. Randomized trials are strongly commended to confirm these results.