Impact of Treatment Time on the Long-Term Outcome of Stroke Patients Treated With Mechanical Thrombectomy

Objective: To assess the long-term functional outcome of stroke in patients treated with mechanical thrombectomy (MT) performed during work hours (on-hours) versus after-hours, weekends, and official holidays (off-hours). Methods: Data on all patients receiving MT at a comprehensive stroke center was collected between December 2014-December 2016. Our primary outcomes were the discharge and 90-day modified Rankin Scale (mRS). We developed propensity scores for off-hours treatment and used inverse probability of treatment weights to address confounding. We estimated logistic regression to assess the relationship between off-hours treatment and favorable patient outcomes. Independent variables include receiving thrombectomy during the off-hours, admission National Institute of Health Stroke Scale (NIHSS), door to groin time in minutes, age, and race. Results: During the study period, 80 (41%) patients underwent thrombectomy during on-hours and 116 (59%) during off-hours. Mean age was 69.1 years for the on-hours group and 64.1 years for the off-hours group (P = .02). There were no statistically significant differences in median admission NIHSS, rate of alteplase administration, mean time from last known well to thrombectomy, rate of revascularization, and rate of hemorrhagic transformation between the 2 groups. Logistic regression analysis showed the probability of a favorable outcome at discharge (mRS <= 2) is 12.6 % lower for off-hours patients (P = .038, [95%CI -.25 to -.01]). For patients with a 90-day mRS (n = 117), the probability of a favorable outcome was 18.7% lower for those treated during the off-hours (P = .029, [95%CI -.36 to -.02]). Conclusions: There is a higher probability of a good functional outcome in acute ischemic stroke patients who receive MT when performed during regular work hours.