The golden hour of stroke intervention: effect of thrombectomy procedural time in acute ischemic stroke on outcome.

Introduction: Outcome studies in acute ischemic stroke (AIS) have focused on time from symptom onset to treatment. The purpose of this study was to investigate whether time to achieve vessel recanalization from groin puncture affects outcomes.

Methods: We studied all AIS cases that underwent intra-arterial therapy between May 2008 and October 2012 at a high volume center for anterior circulation occlusions. Candidacy for thrombectomy is determined by CT perfusion imaging, irrespective of time of onset. Patients were then dichotomized into two groups: 'Early recan' assigned in which recanalization was achieved in ≤60 min from groin puncture and 'Delayed recan' in which procedures extended beyond 60 min. Time to recanalize was also studied as a continuous variable.

Results: 159 patients (53.5% women, mean age 66.4±15.2 years) were identified. The mean National Institutes of Health Stroke Scale (NIHSS) score was similar between 'Early recan' patients (16.8±6.1) compared with 'Delayed recan' patients (15.4±5.8, p=0.149). Among the 'Early recan' patients, recanalization was achieved in 40.7±13.6 min compared with 101.7±32.5 min in the 'Delayed recan' patients (p<0.0001). The likelihood of achieving a good outcome (modified Rankin Scale score 0-2) was higher in the 'Early recan' group (53.6%) compared with the 'Late recan' group (30.8%; p=0.009). On logistic regression analysis, time to recanalization from groin puncture, baseline NIHSS, revascularization, diabetes, and hemorrhages were found to significantly impact on outcome at 90 days, as measured by the modified Rankin Scale.

Conclusions: Our findings suggest that extending mechanical thrombectomy procedure times beyond 60 min increases complications and device cost rates while worsening outcomes. These findings can serve as a time frame of when it is prudent to abort a failed thrombectomy case.