GA superior to conscious sedation in functional recovery from acute posterior circulation stroke: JAMA

China: An original investigation published in JAMA Neurology has reported the superior primary outcome of general anesthesia in functional recovery of patients with Posterior Circulation Acute Ischemic Stroke.

Acute ischaemic stroke or AIS (posterior circulation) is associated with difficulty in treatment, poor outcomes, and a high mortality rate of 80% to 95%. The most important predictor is Early recanalization in such patients at 90 days (favorable outcome).

Endovascular therapy (EVT) is an effective and safe treatment with an improvement in clinical outcomes by 30% and a decrease in mortality by 35 % at 90 days. But some factors may contribute to the mismatched association between high reperfusion rate and poor clinical outcomes, including anesthesia management. During EVT, the most optimal anesthesia choice for AIS patients is still unclear.

The first randomized control study to highlight the relation between anesthesia and neurological outcome in such patients was conducted by the lead researcher Fa Liang with co-researcher Yan Zhao from the Department of Anesthesiology of Beijing Tiantan Hospital from Capital Medical University, China, in 2020. The study was published in BMJ Open. The question raised by the researchers in this first trial was answered in the current research paper published in JAMA Neurology.

The same researcher Dr Liang, with a co-researcher from the previous team, Youxuan Wu, compared General Anesthesia (GA) and Conscious Sedation (CS) in acute posterior circulation stroke patients. The researchers took their previous trial as a reference and verified the effect of anesthesia in Acute Ischemic Stroke (AIS) patients during EVT.

The key points of the study are:

• The study's participants (acute posterior circulation stroke patients) had a mean age of 62 years and were indicated for recanalization.

• Participants were monitored for 3 months.

• Of 210 patients admitted, 87 patients were randomized and analyzed. 18.4% were female, and 81.6% were males.

• 43 patients underwent the endovascular procedure with sedation by GA.

• 44 patients underwent the procedure with CS.

• The primary endpoint was functional independence at 90 days and was evaluated with the modified Rankin Scale (mRS).

• 29.5% of participants in the CS group were transferred to GA.

• Functional independence was higher in the CS group.

• In comparing the two groups, General Anesthesia vs. Conscious sedation, the difference was recorded at 48.8% vs. 54.5% and was non-significant. The risk ratio was 0.89, and the adjusted odds ratio was 0.91.

• The performance of GA was better in successful reperfusion under ITT analysis and was presented as 95.3% vs 77.3% with an adjusted OR of 5.86 and 95 % confidence interval.

According to Joseph P. Broderick et al., The mRS is the primary outcome measure for acute stroke trials. The seven-level, modified Rankin Scale (mRS) has several significant strengths and covers the functional outcomes from no symptoms to death.

The present study defined the modified Rankin score as ≤ 2 (as assigned by assessors blinded to group allocation).

The researchers concluded, "There was no significant difference between the two groups in proportion, general anesthesia vs. conscious sedation, with functional independence at 90-day post-procedure."

CS was not better in comparison to GA and was perhaps worse for the secondary outcome of successful reperfusion, Youxuan Wu added.

References:

Liang F, Wu Y, Wang X, et al. General Anesthesia vs. Conscious Sedation for Endovascular Treatment in Patients With Posterior Circulation Acute Ischemic Stroke: An Exploratory Randomized Clinical Trial. JAMA Neurol.

Liang F, Zhao Y, Yan X, Wu Y, Li X, Zhou Y, Jian M, Li S, Miao Z, Han R, Peng Y. Choice of ANaesthesia for EndoVAScular treatment of acute ischaemic stroke at posterior circulation (CANVAS II): protocol for an exploratory randomized controlled study. BMJ Open. 2020 Jul 31;10(7)

Broderick JP, Adeoye O, Elm J. Evolution of the Modified Rankin Scale and Its Use in Future Stroke Trials. Stroke. 2017 Jul;48(7):2007-2012.