P020 Reperfusion-dependent effects in patients with large acute ischemic strokes – a TENSION subanalysis

<h3>Introduction</h3> Recent RCTs provided evidence that patients with established large infarcts benefit from thrombectomy.[1, 2] However, the effect of the achieved reperfusion level on functional outcome and whether unsuccessful thrombectomy is associated with worse prognosis compared to best medical treatment (BMT) has not been investigated in detail. <h3>Aim of Study</h3> To investigate reperfusion-dependent effects of thrombectomy compared to BMT in patients with large acute ischemic strokes. <h3>Methods</h3> This post hoc analysis of the TENSION Trial analyses treatment effects of thrombectomy per reperfusion level compared to BMT regarding clinical (24h-NIHSS improvement in%), functional (mRS decrease), and safety (ICH) endpoints. Confounder-controlled average treatment effects (ATEs) of thrombectomy reperfusion levels vs. BMT were estimated using inverse probability weighting with regression adjustment. <h3>Results</h3> 253 patients with a median age of 74 years (IQR, 65–80) were included. Reperfusion levels after thrombectomy were observed as follows: mTICI≤2a in 16.5% (21), mTICI-2b/c in 33.1% (42), mTICI-3 in 50.4% (64). ATEs of mTICI≤2a did not reveal worse outcomes compared to BMT with regard to 24h-NIHSS improvement (9.51%, 95%CI, -7.79% to 26.82%, p=0.281), 90-days mRS (-0.38, 95%CI, -0.98 to 0.21, p=0.201), and mortality (-11.76%, 95%CI, -29.01% to 5.49%, p=0.181). Highest ATEs were observed for first-pass-mTICI-3 vs. BMT, reaching significance for all endpoints. Haemorrhage rates did not differ significantly between thrombectomy and BMT groups. <h3>Conclusion</h3> In the TENSION Trial, unsuccessful thrombectomy was not associated with worse outcomes compared to BMT. The highest beneficial effects of thrombectomy versus BMT were estimated for first-pass complete reperfusion. <h3>Disclosure of Interest</h3> no.