ABSTRACT NUMBER: ESOC2026A2363 ENDOVASCULAR THERAPY VS MEDICAL MANAGEMENT FOR VERTEBROBASILAR ARTERY OCCLUSION BEYOND 12 HOURS: AN INDIVIDUAL PATIENT DATA POOLED ANALYSIS FROM THE VERITAS TRIALS

Abstract Background and aims We compared endovascular therapy (EVT) with standard medical management (SMM) in patients randomized and treated more than 12 hours from estimated symptom onset in the VERITAS trials and assessed potential treatment-time interactions. Methods VERITAS was a meta-analysis combining individual patient data from 4 trials. The primary outcome was a favorable functional outcome (modified Rankin Scale [mRS] 0–3) at 90 days. Secondary outcomes included functional independence (mRS 0–2) and ordinal mRS shift. Safety outcomes included symptomatic intracranial hemorrhage (sICH) and 90-day mortality. Multivariable regression adjusted for confounders, and the interaction between treatment allocation and time to randomization was tested. Results Of 988 patients, 84 met criteria for the >12-hour analysis (48 EVT, 36 SMM). Despite higher rates of intracranial atherosclerotic disease (76.6% vs 38.9%) in the EVT group, it was associated with higher odds of favorable outcomes (mRS 0–3: 47.92% vs 27.78%, aOR 4.24, 95% CI 1.17–15.28, p=0.027). The ordinal shift analysis also favored EVT (acOR 3.44, 95% CI 1.37–8.65, p=0.009). Safety outcomes were comparable: sICH occurred in 7.0% vs 0.0% (p=0.273) and 90-day mortality was 33.33% vs 44.44% (aOR 0.44, 95% CI 0.14–1.41, p=0.168). There was no significant interaction between EVT effect and treatment window(p=0.75). Conclusions In VBAO patients treated beyond 12 hours, EVT significantly increased the odds of favorable outcomes and reduced disability without excess sICH or mortality. These findings support a substantial role for EVT in extended presentations, with relative benefit consistent across early and late treatment windows. Conflict of interest None