Coronary Sinus Narrowing for Treating Refractory Angina: REDUCER-I Multicenter "Real-World" Observational Study Primary Endpoint Analysis.

Background: Patients with refractory angina are often ineligible for revascularization and have poor quality of life despite optimal medical therapy. The coronary sinus (CS) Reducer (Shockwave Medical Inc) was safe and effective in the treatment of refractory angina in the COSIRA (Coronary Sinus Reducer for Treatment of Refractory Angina) randomized sham-controlled trial.
Objectives: This study sought to perform the primary endpoint analysis of the complete REDUCER-I (An Observational Study of the Neovasc Reducer System) study cohort.
Methods: REDUCER-I is a nonrandomized, "real-world" study of patients with refractory angina treated with the CS Reducer conducted at 25 centers from 9 European countries. The primary effectiveness endpoint was an improvement in Canadian Cardiovascular Society (CCS) class at 6 months. The primary safety endpoints were major adverse cardiac events and device- or procedure-related serious adverse events through 30 days. Study follow-up is planned through 5 years with some interim 3-year analyses included here.
Results: From 2016 to 2023, 400 patients were enrolled, including 78.0% (312/400) male patients, 54.3% (216/398) with previous myocardial infarction, 73.6% (293/398) with previous revascularization, and 72.0% (280/389) CCS class III/IV. Major adverse cardiac event and serious adverse event rates were 1.6% (95% CI: 0.7-3.6) and 1.1% (4/371), respectively, with no deaths within 30 days. At 6 months, 69.8% (240/344) of patients improved by ≥1 CCS class. Six-minute walk distances improved by 34.1 ± 85.8 m at 6 months (P < 0.0001). Interim 3-year results showed CCS class and Seattle Angina Questionnaire quality of life improvements were sustained (P < 0.0001).
Conclusions: The complete primary endpoint analysis of the REDUCER-I study shows patients with refractory angina were safely and effectively treated with the CS Reducer. Improvements in angina and quality of life appear sustained through 3 years.
Competing Interests: Funding Support and Author Disclosures The REDUCER-I study is sponsored by Shockwave Medical Inc, although no specific funding was provided for this analysis. Dr Verheye serves as a proctor for Shockwave Medical Inc; and has received honoraria from Shockwave Medical Inc. Dr de Silva serves as a proctor for Shockwave Medical Inc; and has received honoraria from Shockwave Medical Inc. Dr West is an employee of Shockwave Medical Inc. Dr Banai has received honoraria from Shockwave Medical Inc; and is on the Advisory Board for Shockwave Medical Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)