By Matthew E. Fink, MD

Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital

Dr. Fink reports no financial relationships relevant to this field of study.

Source: Sheth SA, et al. Time to endovascular reperfusion and degree of disability in acute stroke. Ann Neurol 2015;78:584-593.

In the past year, multiple clinical trials have reported that intra-arterial endovascular reperfusion with mechanical clot extraction, using the SOLITAIRE stent retriever device and others, results in better neurological outcomes than treating patients with intravenous thrombolysis alone with TPA. There is still uncertainty regarding the maximum time window, and how important early intervention is as related to neurological recovery and long-term outcomes. The investigators used the combined databases of the SWIFT (Lancet 2012) and STAR (Stroke 2013) trials to identify patients treated with the SOLITAIRE device who achieved substantial reperfusion. They then ranked the 90-day modified Rankin scale outcomes for "time of onset to recanalization" (OTR) time intervals ranging from 180 min to 480 min.

Analysis of these data showed substantial time-related reductions in disability for the entire range of outcomes. A shorter OTR time was associated with an improved 90-day Rankin Scale outcome in all groups. The mean Rankin scores were 1.4 for the 120-240 min OTR group, 2.40 for the 241-360 min group, and 3.3 for the 361-660 min group (P < 0.001). There were no significant differences between the groups in the incidence of intracerebral hemorrhage, mortality, or length of hospitalization. The predicted probability and confidence interval of good neurological outcome (mRS 0-2) at 90 days was a continuous variable inversely related to the time from symptom onset to recanalization. For every 15-min acceleration in the time to reperfusion, 34 per 1000 patients treated will have improved disability outcomes, which translates to 1 out of 100 patients improved, for every 5 minutes of reduced OTR time.