Analysis of Workflow and Time to Treatment on Thrombectomy Outcome in the Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) Randomized, Controlled Trial

Circulation. 2016 Jun 7;133(23):2279-86. doi: 10.1161/CIRCULATIONAHA.115.019983. Epub 2016 Apr 13.


Background: The Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial used innovative imaging and aggressive target time metrics to demonstrate the benefit of endovascular treatment in patients with acute ischemic stroke. We analyze the impact of time on clinical outcome and the effect of patient, hospital, and health system characteristics on workflow within the trial.

Methods and results: Relationship between outcome (modified Rankin Scale) and interval times was modeled by using logistic regression. Association between time intervals (stroke onset to arrival in endovascular-capable hospital, to qualifying computed tomography, to groin puncture, and to reperfusion) and patient, hospital, and health system characteristics were modeled by using negative binomial regression. Every 30-minute increase in computed tomography-to-reperfusion time reduced the probability of achieving a functionally independent outcome (90-day modified Rankin Scale 0-2) by 8.3% (P=0.006). Symptom onset-to-imaging time was not associated with outcome (P>0.05). Onset-to-endovascular hospital arrival time was 42% (34 minutes) longer among patients receiving intravenous alteplase at the referring hospital (drip and ship) versus direct transfer (mothership). Computed tomography-to-groin puncture time was 15% (8 minutes) shorter among patients presenting during work hours versus off hours, 41% (24 minutes) shorter in drip-ship patients versus mothership, and 43% (22 minutes) longer when general anesthesia was administered. The use of a balloon guide catheter during endovascular procedures shortened puncture-to-reperfusion time by 21% (8 minutes).

Conclusions: Imaging-to-reperfusion time is a significant predictor of outcome in the ESCAPE trial. Inefficiencies in triaging, off-hour presentation, intravenous alteplase administration, use of general anesthesia, and endovascular techniques offer major opportunities for improvement in workflow.

Clinical trial registration: URL: Unique identifier: NCT01778335.

Keywords: cerebrovascular disorders; emergency treatment; endovascular procedures; stroke; thrombolytic therapy.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravenous
  • After-Hours Care
  • Anesthesia, General
  • Brain Ischemia / diagnostic imaging
  • Brain Ischemia / mortality
  • Brain Ischemia / therapy*
  • Cerebral Angiography / methods
  • Computed Tomography Angiography
  • Disability Evaluation
  • Endovascular Procedures* / adverse effects
  • Endovascular Procedures* / mortality
  • Fibrinolytic Agents / administration & dosage
  • Humans
  • Predictive Value of Tests
  • Punctures
  • Risk Factors
  • Stroke / diagnostic imaging
  • Stroke / mortality*
  • Stroke / therapy*
  • Thrombectomy* / adverse effects
  • Thrombectomy* / mortality
  • Thrombolytic Therapy* / adverse effects
  • Thrombolytic Therapy* / mortality
  • Time Factors
  • Time and Motion Studies*
  • Time-to-Treatment*
  • Tissue Plasminogen Activator / administration & dosage
  • Treatment Outcome
  • Triage
  • Workflow*


  • Fibrinolytic Agents
  • Tissue Plasminogen Activator

Associated data


Grants and funding