Outcome of patients with proximal vessel occlusion of the anterior circulation and DWI-PWI mismatch is time-dependent

Background and purpose Patients with ischemic stroke and large vessel occlusion are assumed to benefit from endovascular therapy (ET) independent of the symptom onset-to-treatment time (OTT) if they present with a mismatch of diffusion- and perfusion-weighted imaging (DWI-PWI mismatch). We aimed at studying the influence of OTT on clinical outcome in these patients. Methods Retrospective database review in a tertiary care university hospital. All patients presented with proximal vessel occlusion of the anterior circulation and DWI-PWI mismatch. Primary outcome was the influence of OTT on modified Rankin scale (mRS) score three months after treatment, dichotomized in favourable (0–2) and unfavourable outcome (3–6). Secondary outcome was the effect of OTT on the shift of the mRS score. Patients treated within an early time window ( Results 139 patients were included. The rate of favourable outcome was significantly higher in patients who were treated in an early compared to those treated in a late time window (31 [49%] vs. 20 patients [27%], p = 0.005). Adjusted multivariate logistic regression revealed that late treatment was an independent negative predictor of favourable outcome (odds ratio 0.39, confidence interval [0.18–0.84]; p = 0.016). A shift towards higher mRS scores for late treatment was evident (p = 0.015). In sensitivity analysis, OTT remained an independent predictor when evaluated as continuous variable. These findings were confirmed in patients with a comparable DWI-PWI mismatch according to the definitions from large trials (DEFUSE 2, DEFUSE 3, SWIFT-PRIME, EXTEND-IA). Conclusion Outcome of patients with comparable DWI-PWI mismatch is time-dependent.