Abstract Number: Esoc2026a2378 Time-Dependent Neurological Benefit of Reperfusion Quality in Mechanical Thrombectomy: A Nationwide Registry Analysis

Abstract Background and aims Endovascular thrombectomy (EVT) outcomes are strongly time-dependent, yet procedural time is often assumed to relate linearly to neurological recovery, and reperfusion quality is frequently treated as uniformly beneficial. Whether the neurological value of higher reperfusion grades varies across procedural time remains unclear. Methods We performed a nationwide registry-based analysis using merged stroke-level data from the Swedish Endovascular Stroke Registry (EVAS). Neurological improvement was defined as change in NIHSS from baseline to 24 hours (ΔNIHSS). Puncture-to-reperfusion time was modeled as a continuous, non-linear exposure. Reperfusion quality was categorized as TICI 2b versus TICI 2c/3. Interaction analyses assessed whether the association between reperfusion quality and neurological recovery varied across procedural time. Results Neurological improvement declined continuously with increasing puncture-to-reperfusion time, demonstrating a non-linear time–outcome relationship. Early along the curve, neurological recovery was high and comparable across reperfusion grades. As procedural time increased and the slope steepened, higher reperfusion quality was associated with greater neurological improvement compared with TICI 2b. At longer procedural durations, overall neurological benefit diminished despite successful recanalization. A disproportionate share of lost neurological improvement originated from procedures within the upper tail of procedural time. Conclusions Neurological recovery after EVT is governed by a continuous interaction between procedural time and reperfusion quality. The clinical value of achieving higher reperfusion grades is time-dependent. These findings suggest that system-level improvements may be maximized by targeting prolonged procedural outliers and increasing direct intake to thrombectomy-capable centers to reduce non-therapeutic delays. Conflict of interest Alex Szolics: Nothing to Disclose