Background
While endovascular thrombectomy (EVT) is effective in large vessel occlusion (LVO) stroke, the utility of bridging thrombolysis has been questioned, particularly in patients presenting 4.5-24 hours after onset (‘late’ treatment window). We aimed to determine the efficacy of pre-thrombectomy thrombolysis in patients with respect to radiographic reperfusion and subsequent functional outcomes.
Methods
This was a retrospective cohort study of patients referred for EVT from regional (Telestroke) and metropolitan stroke centres between 1/1/2020 and 31/12026. Patients were categorized by thrombolysis status (IVT vs no IVT), with prespecified subgroup analyses performed in early (≤4.5 hours) and late (>4.5 hours) treatment windows. The primary outcome was pre-thrombectomy reperfusion (TICI≥2b). Propensity Score Overlap Weighting (PSOW) was applied to create a weighted cohort with balanced baseline covariates.
Results
1154 patients were included. In total 603 received IVT, in which 174 underwent late-window reperfusion. 551 did not receive IVT, in which 429 underwent late window reperfusion. IVT was associated with pre-thrombectomy reperfusion (PSOW-OR 15.2, [6.56, 35.0], p<0.001) in both early (PSOW-OR 7.06, [0.93, 53.46], p=0.028) and late windows (PSOW-OR 21.85, [7.47, 63.96], p<0.001). Thrombolysis was also associated with a favourable ordinal shift in 90-day mRS overall (PSOW-OR 1.69, [1.24, 2.33], p=0.001), most evident in the late-window (PSOW-OR 1.66, [1.03, 2.64], p=0.031). Symptomatic haemorrhagic transformation was not significantly increased in any group.
Conclusion
Bridging thrombolysis was associated with increased pre-thrombectomy reperfusion and improved functional outcomes up to 24 hours after onset in patients with confirmed vessel occlusion. Haemorrhagic transformation rates were unchanged in either time window.