Abstract
Importance: Clinical trials focusing on new mechanical thrombectomy (MT) technologies have been typically single-arm studies using historical comparison data to determine the safety and efficacy of the novel device. To date, there has not been a contemporaneous prospective, randomized, controlled study comparing standard to newer designed stent-retrievers.
Objective: To evaluate the safety and efficacy of the pRESET (phenox Ltd) compared to the Solitaire (Medtronic Corp) thrombectomy devices in the treatment of large vessel occlusion strokes (LVOS).
Methods: Multicenter, prospective, randomized, open-label, blinded endpoint, core lab adjudicated, non-inferiority trial that enrolled 340 patients from October 2019 to February 2022 across 19 US & 5 German sites. Patients aged ≥ 18 years with either anterior or posterior circulation LVOS were included up to 8 hours after symptom onset. Patients were randomly assigned in a 1:1 ratio to either pRESET or Solitaire for the first three device passes.The Primary Endpoint was the proportion of patients achieving a modified Rankin Scale score of 0-2, analyzed by intent to treat with a non-inferiority margin of 0.125 based on the lower bound 95% Confidence Interval. The Primary Safety Endpoint was the proportion of subjects with device- or procedure-related symptomatic intracerebral hemorrhage at 24 (-8/+12) hours as per the SITS-MOST criteria. Secondary Outcome Measures included the rates of (1) Successful Revascularization (defined as expanded Thrombolysis in Cerebrovascular Infarction [eTICI] ≥2b50 ≤3 passes of the assigned device; (2) eTICI ≥2c following the first pass of the assigned device; (3) 90-day mortality and (4) Distribution of 90-day mRS across the entire spectrum of disability (ordinal shift).
Results: The study database was locked in August 2022. The analysis is ongoing and the final results will be presented at the 2023 International Stroke Conference.
Conclusions and Relevance: PROST is the first randomized clinical trial aiming to compare a novel versus an established stent-retriever technology, establishing a new scientific benchmark for stroke device trials. (ClinicalTrials.gov: NCT03994822).