Balloon guide catheters for endovascular thrombectomy in patients with acute ischaemic stroke due to large-vessel occlusion in China (PROTECT-MT): a multicentre, open-label, blinded-endpoint, randomised controlled trial.

Background: The effectiveness of using a balloon guide catheter during endovascular thrombectomy in patients with acute ischaemic stroke due to large vessel occlusion of the anterior circulation remains uncertain. We aimed to assess the effectiveness and safety of using a balloon guide catheter during endovascular thrombectomy, compared with using a conventional guide catheter, in this patient population.

Methods: We conducted a multicentre, open-label, blinded-endpoint, randomised controlled trial at 28 hospitals in China. Adults aged 18 years or older with acute ischaemic stroke who were able to receive endovascular thrombectomy within 24 h after symptom onset, according to local guidelines, were eligible. Patients were randomly assigned (1:1) to the balloon guide catheter group or the conventional guide catheter group using a central internet-based system with a minimisation algorithm. The treating physicians and patients were aware of treatment allocation, but clinical outcomes were collected by local trained physicians who were masked. Neurological assessments were performed at baseline, 24 h after randomisation, and at 7 days or hospital discharge (whichever occurred first). The primary outcome was functional recovery, assessed by change in modified Rankin Scale (mRS) scores (ranging from 0 [no symptoms] to 6 [death]) at 90 days in the intention-to-treat population and obtained from structured interviews. Treatment effect was estimated using ordinal logistic regression with adjustment for site and baseline prognostic factors (time from symptom onset to randomisation, the preferred thrombectomy strategy, baseline National Institutes of Health Stroke Scale score, prestroke function [estimated mRS score], and age). This trial is registered with ClinicalTrials.gov, NCT05592054 (terminated).

Findings: Between Feb 7 and Nov 13, 2023, 1698 patients were assessed for eligibility and 329 were randomly assigned to the balloon guide catheter group (n=164) or conventional guide catheter group (n=165) when the trial was paused and subsequently terminated on April 18, 2024, due to safety concerns. The median age was 69 years (IQR 59-76). Of 329 patients, 201 (61%) were male and 128 (39%) were female. Participants in the balloon guide catheter group had significantly worse scores on the mRS at 90 days than those in the conventional guide catheter group (adjusted common odds ratio 0·66 [95% CI 0·45-0·98]; p=0·037). All-cause mortality at 90 days was numerically higher in the balloon guide catheter group than in the conventional guide catheter group (39 [24%] vs 26 [16%]). There were no statistically significant differences between groups in intracranial haemorrhage, symptomatic intracranial haemorrhage, or other serious adverse events.

Interpretation: Compared with conventional guide catheters, the use of balloon guide catheters led to worse functional recovery in patients receiving endovascular thrombectomy for intracranial large vessel occlusion. Future studies are needed to confirm these results.

Funding: National Natural Science Foundation of China, Shanghai Hospital Development Center, Biopharma Industry Promotion Center Shanghai, and Ton-bridge Medical Technology.

Translation: For the Chinese translation of the abstract see Supplementary Materials section.