Bridging thrombolysis with tenecteplase versus endovascular thrombectomy alone for large-vessel anterior circulation stroke: a target trial emulation analysis.

Background Whether bridging thrombolysis with tenecteplase is beneficial compared with thrombectomy alone in patients who had a stroke with large-vessel occlusion remains unclear.Methods This is a causal inference study of observational data from the trials SWIFT DIRECT and EXTEND-IA TNK Parts 1 and 2 applying target trial emulation. We compared patients receiving thrombectomy alone to patients receiving tenecteplase 0.25 mg/kg or 0.40 mg/kg before thrombectomy. The primary outcome was functional independence (modified Rankin Scale (mRS) of 0-2) at 90 days. Secondary outcomes included improvement over the full ordinal mRS scale, freedom of disability (mRS 0-1), mortality and occurrence of symptomatic intracranial haemorrhage. The average causal treatment effect was estimated via inverse probability of treatment weighting and G-Computation. We calculated standardised risk differences (SRDs) and adjusted (common) ORs (a(c)ORs).Results Of 377 patients included in the target trial, 187 received thrombectomy alone and 190 tenecteplase before thrombectomy. Tenecteplase before thrombectomy did not increase the probability of patients achieving functional independence (SRD 0.04 (95% CI -0.06 to 0.13)) but resulted in a significant improvement in the mRS overall (acOR 1.56 (95% CI 1.07 to 2.23)) and in a higher probability of freedom from disability (SRD 0.10 (95% CI 0.01 to 0.20)). The probability for improvement of functional outcomes was further increased in patients treated within 140 min after onset (ordinal mRS acOR 1.63 (95% CI 1.04 to 2.56)). No significant differences in safety outcomes were observed between the two groups.Conclusion Tenecteplase before thrombectomy compared with thrombectomy alone did not increase the probability of functional independence but resulted in significant improvement over the full mRS scale. This improvement was most evident in patients treated early.