ABSTRACT NUMBER: ESOC2026A663 IMPACT OF TIME TO TREATMENT IN OCTOGENARIANS UNDERGOING MECHANICAL THROMBECTOMY ON SUCCESSFUL RECANALISATION RATES, REDUCTION IN NIHSS SCORE AND MORTALITY AT UNIVERSITY HOSPITAL SOUTHAMPTON

Abstract Background and aims A high proportion of patients referred for mechanical thrombectomy (MT) are frail and aged over 80. Current guidelines recommend using ASPECTS scores and CTA to proceed to MT up to 12hrs and CTP between 12-24hrs. We analysed our data to review the impact of time to treatment on outcomes. Methods 105 patients aged over 80 underwent MT at UHS in 2025. We looked at the impact time to groin puncture on successful recanalization rates (TICI 2C/3), reduction in NIHSS score and mortality at 3 months in patients treated at 0-5hrs, 5-12hrs, and >12hrs. Results 40 patients were treated at 0-5hrs. Mean NIHSS 18 - 14, TICI 2C/3 34/40 (85%), and mortality 7/40 (18%). 50 patients were treated at 5-12hrs. Mean NIHSS 17 - 15, TICI 2C/3 34/50 (68%), and mortality 22/50 (44%) 15 patients were treated >12hrs. Mean NIHSS 20 - 17, TICI 2C/3 8/15 (53%), and mortality 8/15 (53%). 10/15 had CTP with CBF <30% to Tmax>6.0s >15mls and CBF <30% <70mls. Conclusions A significantly higher proportion of patients achieved successful recanalisation, a reduction in NIHSS score and lower mortality when treated within 5hrs. Beyond 5hrs recanalisation rates fell from 85 – 68%, as did the reduction in NIHSS and mortality more than doubled. Worse outcomes still were seen >12hrs with mortality >50%, and more modest reductions in NIHSS score despite using CTP to predict salvageable penumbra. Delayed time to groin puncture beyond 5 hours in octogenarians reduces successful recanalisation rates and improvements in neurological outcome and increases mortality. Conflict of interest Dr Richard Marigold: nothing to disclose