General Anesthesia Negatively Affects Outcomes in MR CLEAN Trial

Those who received local anesthesia had better functional outcomes in the landmark trial.

NASHVILLE — Among patients with acute ischemic stroke who were treated with intra-arterial therapy (IAT), those who received general anesthesia had worse functional outcomes than patients who received local anesthesia, according to late-breaking trial data from the MR CLEAN trial.

Olvert A. Berkhemer, MD, study investigator, added during his presentation at the International Stroke Conference 2015 that general anesthesia was also associated with delayed treatment initiation, although procedural duration and time to revascularization were similar.

For the multicenter, prospective, randomized, open label MR CLEAN trial, Berkhemer, of the Academic Medical Center in Amsterdam, and fellow investigators enrolled patients with acute ischemic stroke who had a proximal arterial occlusion in the anterior cerebral circulation that could be treated within six hours of symptom onset. Researchers prospectively collected general anesthesia use data from an online database.

Because of the intention-to-treat principle, patients who were converted to general anesthesia during IAT were considered part of the local anesthesia group.

The primary outcome was modified Rankin Scale (mRS) score at 90 days, with good clinical outcome defined as mRS score ≤2 in post-hoc analysis. Secondary outcomes included timing, safety parameters and procedural-related adverse events.

Overall, 500 patients were enrolled in the trial, of whom 233 were allocated to receive IAT (intervention) and 267 to standard therapy (control). Of the 216 patients who had catheter angiography, 79 (36.6%) were treated under general anesthesia, which consisted of intubation combined with IV and/or inhaled anesthetic agents.

Baseline characteristics were well balanced between groups.

Dr. Berkhemer and colleagues observed that the time from door to initiation of IAT was longer in the general anesthesia group (162 minutes vs. 134 minutes), whereas procedural duration times were similar (general anesthesia, 76 minutes vs. local anesthesia, 79 minutes).

Primary endpoint analysis revealed the following adjusted ORs:

  • Intervention vs. control, 1.67 (95% CI, 1.21-2.30)
  • Local vs. general anesthesia, 2.13 (95% CI, 1.46-3.11)
  • General anesthesia vs. control, 1.09 (95% CI, 0.69-1.71).

Compared with the general anesthesia arm, patients who received IAT under local anesthesia were more likely to have a good clinical outcome (38% vs. 23%; P=.026), despite the similar condition of patients prior to treatment in both groups.

Rates of symptomatic intracranial hemorrhage and mortality were similar, and there were no procedural-related safety concerns in both groups.

For more coverage of the International Stroke Conference 2015, go here.


  1. Berkhemer OA et al. Late-Breaking Trial #17. Presented at: International Stroke Conference 2015; Feb. 11-13, 2015; Nashville, Tennessee.