Outcomes After Endovascular Therapy With Procedural Sedation vs General Anesthesia in Patients With Acute Ischemic Stroke: The AMETIS Randomized Clinical Trial

Abstract

Importance: General anesthesia and procedural sedation are common practice for mechanical thrombectomy in acute ischemic stroke. However, risks and benefits of each strategy are unclear.

Objective: To determine whether general anesthesia or procedural sedation for anterior circulation large-vessel occlusion acute ischemic stroke thrombectomy are associated with a difference in periprocedural complications and 3-month functional outcome.

Design, setting, and participants: This open-label, blinded end point randomized clinical trial was conducted between August 2017 and February 2020, with final follow-up in May 2020, at 10 centers in France. Adults with occlusion of the intracranial internal carotid artery and/or the proximal middle cerebral artery treated with thrombectomy were enrolled.

Interventions: Patients were assigned to receive general anesthesia with tracheal intubation (n = 135) or procedural sedation (n = 138).

Main outcomes and measures: The prespecified primary composite outcome was functional independence (a score of 0 to 2 on the modified Rankin Scale, which ranges from 0 [no neurologic disability] to 6 [death]) at 90 days and absence of major periprocedural complications (procedure-related serious adverse events, pneumonia, myocardial infarction, cardiogenic acute pulmonary edema, or malignant stroke) at 7 days.

Results: Among 273 patients evaluable for the primary outcome in the modified intention-to-treat population, 142 (52.0%) were women, and the mean (SD) age was 71.6 (13.8) years. The primary outcome occurred in 38 of 135 patients (28.2%) assigned to general anesthesia and in 50 of 138 patients (36.2%) assigned to procedural sedation (absolute difference, 8.1 percentage points; 95% CI, -2.3 to 19.1; P = .15). At 90 days, the rate of patients achieving functional independence was 33.3% (45 of 135) with general anesthesia and 39.1% (54 of 138) with procedural sedation (relative risk, 1.18; 95% CI, 0.86-1.61; P = .32). The rate of patients without major periprocedural complications at 7 days was 65.9% (89 of 135) with general anesthesia and 67.4% (93 of 138) with procedural sedation (relative risk, 1.02; 95% CI, 0.86-1.21; P = .80).

Conclusions and relevance: In patients treated with mechanical thrombectomy for anterior circulation acute ischemic stroke, general anesthesia and procedural sedation were associated with similar rates of functional independence and major periprocedural complications.

Trial registration: ClinicalTrials.gov Identifier: NCT03229148.

Figure 1.. Randomization and Treatment of the Patients

mRS indicates modified Rankin Scale. ^aOther reasons include anterior cerebral artery or nonaccessible distal middle cerebral artery occlusion, investigation team not available (night shifts or weekends), inclusion in other trial, or protected by law. ^bThree randomization errors occurred without patient assignment due to informatic issues. ^cOn March 7, 2019, after 270 patients had been enrolled, 44 patients were excluded (22 in the general anesthesia group and 22 in the procedural sedation group) because patients withdrew consent, had spontaneous revascularization, or were found to be ineligible. The study protocol was then amended accordingly in July 2019, and 59 additional patients were randomly assigned to a study group to obtain the full sample, including 47 patients (24 in the general anesthesia group and 23 in the procedural sedation group) who were evaluable for assessment of the primary outcome.

Figure 2.. Distribution of Functional Outcomes at 90 Days in the Modified Intention-to-Treat Population

Shown is the distribution of scores for disability on the modified Rankin Scale (mRS) among patients in the general anesthesia group and the procedural sedation group in the modified intention-to-treat population (A) and in subgroups defined according to major periprocedural complications (B). Scores for disability range from 0 to 6, with 0 indicating no neurologic deficit; 1, no clinically significant disability; 2, slight disability; 3, moderate disability requiring some help; 4, moderately severe disability; 5, severe disability; and 6, death. Functional independence was defined as an mRS score of 0, 1, or 2. Major periprocedural complications were procedure-related serious adverse events (vessel perforation or dissection), pneumonia, myocardial infarction, cardiogenic acute pulmonary edema, or progression to malignant stroke within 7 days after endovascular thrombectomy. There was significant heterogeneity according to the presence or absence of major periprocedural complications and functional independence at 90 days (P for interaction < .001).

Figure 3.. Prespecified Subgroup Analyses of the Primary Outcome in the Modified Intention-to-Treat Population

The forest plot shows the risk ratio for the primary outcome (functional independence at 90 days and absence of major periprocedural complications at 7 days after endovascular thrombectomy) in 10 prespecified subgroups. ASPECTS indicates Alberta Stroke Program Early Computed Tomography Score; NIHSS, National Institutes of Health Stroke Scale.