Assistential Efficiency, Epidemiological Profile, and Clinical Outcomes of Implementing Thrombectomy Protocols in Expanded Time Windows: Implications for Integrated Cardioneurovascular Systems

Abstract Background: Acute ischemic stroke (AIS) due to large vessel occlusion (LVO) remains a leading cause of disability and mortality worldwide. Traditional time windows for mechanical thrombectomy (MT) have been limited to 6 hours from symptom onset, but recent evidence from landmark trials such as DAWN and DEFUSE-3 has extended this window to 24 hours in select patients with favorable imaging profiles. This study evaluates the assistential efficiency, epidemiological profile, and clinical outcomes of implementing expanded time window MT protocols in a Brazilian integrated cardioneurovascular system, while exploring implications for resource allocation and multidisciplinary care. Methods: A retrospective cohort study was conducted from January 2020 to December 2025 at a tertiary care center in Bahia, Brazil, involving 450 patients with AIS and confirmed LVO. Patients were stratified into standard (≤6 hours) and expanded (>6-24 hours) time windows. Selection for expanded windows utilized perfusion imaging (CT perfusion or MRI) to identify mismatch between infarct core and penumbra. Primary outcomes included 90-day modified Rankin Scale (mRS) scores (good outcome: mRS 0-2), assistential efficiency (time from door to groin puncture), and epidemiological factors (age, comorbidities, stroke etiology). Secondary outcomes encompassed symptomatic intracranial hemorrhage (sICH), mortality, and system-level implications for cardioneurovascular integration. Data were analyzed using logistic regression and Kaplan-Meier survival curves. Results: Of 450 patients, 280 (62%) were treated in the standard window and 170 (38%) in the expanded window. The expanded group had a mean time from last known well (LKW) to treatment of 12.4 ± 5.6 hours. Good functional outcomes were achieved in 58% of expanded window patients versus 65% in standard (adjusted OR 0.82, 95% CI 0.61-1.10; p=0.18). Assistential efficiency improved by 22% post-protocol implementation, with mean door-to-puncture time reducing from 120 to 93 minutes (p