Duration of symptomatic stroke and successful reperfusion with endovascular thrombectomy for anterior circulation large vessel occlusive stroke

Abstract

Background: It has been reported that longer time intervals from stroke onset to endovascular therapy are associated with lower rates of successful reperfusion in acute ischemic stroke patients with large vessel occlusion. However, procedural variables and potential mechanisms of this association have not been fully elucidated.

Methods: We performed a secondary analysis of individual patient data from the North American Solitaire Stent Retriever Acute Stroke (NASA) and Trevo Stent-Retriever Acute Stroke (TRACK) registries. We included patients with occlusion of the internal carotid artery or middle cerebral artery (M1 and M2 segments) who were treated by mechanical thrombectomy within 24 hours of last known normal. The primary outcome was reperfusion, defined as a Thrombolysis In Cerebral Infarction (TICI) score ≥2b. The secondary outcome was reperfusion on the first pass. The primary predictor was duration of symptomatic stroke, defined as time from last known normal to time of final pass. Adjusted logistic regression models were utilized to determine associations between variables and outcome.

Results: We included 506 patients, of which 401 (79.3%) achieved successful reperfusion (TICI 2b/3). The mean (SD) duration of symptomatic stroke was 6.8 (3.5) hours and in the adjusted logistic regression model the duration of symptomatic stroke was associated with reperfusion (OR 0.90, 95% CI 0.84 to 0.96) and reperfusion on the first pass (OR 0.89, 95% CI 0.83 to 0.95). In that model, the predicted probability of reperfusion was 88% (95% CI 0.83 to 0.92) at 1 hour, 81% (95% CI 0.78 to 0.84) at 6 hours, 70% (95% CI 0.63 to 0.77) at 12 hours, and 42% (95% CI 0.17 to 0.67) at 24 hours (p_trend=0.001). Reperfused patients were significantly younger, more likely to be male, and to have had a balloon guide catheter used during the procedure.

Conclusion: In a real-world cohort of acute ischemic stroke patients with anterior circulation occlusion treated with endovascular therapy, longer duration of symptomatic stroke is associated with lower rates of successful reperfusion and reperfusion on the first pass.

Keywords: acute ischemic stroke; endovascular thrombectomy; large vessel occlusion; neurologic outcome.

Figure 1.

A) Histogram of clot dwell times, B) Predicted probability* of reperfusion for the middle cerebral artery (MCA) segments and internal carotid artery (ICA). *Adjusted for patient age, sex, race, baseline systolic blood pressure, NIH stroke scale, device (Solitaire vs. Trevo), site of occlusion, number of passes, balloon guide catheter, clot aspiration, rescue treatment, intravenous alteplase, and intraarterial alteplase.

Figure 2.

Predicted probability* of A) reperfusion and B) first pass effect with 95% confidence interval. *Adjusted for patient age, sex, race, baseline systolic blood pressure, NIH stroke scale, device (Solitaire vs. Trevo), site of occlusion, number of passes (model fit to reperfusion only), balloon guide catheter, clot aspiration, rescue treatment, intravenous alteplase, and intraarterial alteplase.