Evaluation of FreedomFlow Debulking Effectiveness Using Real-World Evidence From the VQI Database

Study Design: Cardio Flow’s FAST II clinical trial enrolled patients with different baseline lesion characteristics and clinical severity when compared to previously published atherectomy studies that used angiographic core lab adjudication: FAST II lesions were longer; patients with more critical limb-threatening ischemia were included; and a greater number of chronic total occlusions were treated.

In comparing the debulking effectiveness of the FreedomFlow device, a control group of patients with well-matched pre-treatment characteristics was identified from a national VQI database. Control patients were selected using the IPTW propensity score methodology to identify comparable pre-treatment data: sex, age, Rutherford classification, artery treated, lesion length, baseline stenosis, reference vessel diameter, and calcification score.

A blinded, randomized core laboratory measurement of all angiographic treatment data was then performed to assess the debulking effectiveness of atherectomy treatment in all patients.

Primary Endpoint: The primary effectiveness endpoint, Post Atherectomy Stenosis (PAS), was defined as the post-atherectomy residual stenosis without adjunctive therapy, compared between groups.

Results: A comparative analysis was performed on the primary effectiveness endpoint, demonstrating that the FreedomFlow debulking effectiveness is non-inferior to other marketed rotational atherectomy devices.

Post-Atherectomy Diameter Stenosis (mean ± SD): FAST II = 41.1 ± 19.2 vs. PVI Registry 46.2 ±  17.1; mean values were significantly different (p = 00000022).

Secondary endpoint analyses showed that the weighted mean stenosis reduction for the FAST II group was 21.9%, compared to 23.2% for the VQI control cohort; the weighted mean final diameter stenosis reduction (after all treatment) for the FAST II group was 21.0% compared to 16.2% for the VQI control cohort.

In short, the FreedomFlow FAST II patients had more debulking than the VQI control group following treatment, demonstrating good acute outcomes in terms of both post-atherectomy stenosis as well as a reduction in stenosis.