Use of a Novel, Self-Expanding Coronary Sinus Reducer to Treat Symptomatic Epicardial and Microvascular Ischemic Heart Disease: Preclinical and First-in-Human Experience

Background A novel self-expanding, recapturable, repositionable hourglass nitinol-mesh coronary sinus reducer (CSR) has been designed to improve symptoms in patients with coronary microvascular dysfunction (CMD) or with obstructive epicardial coronary artery disease (CAD). We report the preclinical and first-in-human experience with a novel self-expanding CSR. Methods Twelve symptomatic patients (mean age 66.8 years, 58% men) with either CMD (n = 6) or obstructive CAD (n = 6) were treated with the A-FLUX CSR. Patients were followed up at approximately 1, 3, and 6 months to assess safety and symptom improvements (Canadian Cardiovascular Society [CCS] angina class and Seattle Angina Questionnaire [SAQ]). Tissue healing responses were evaluated following A-FLUX CSR implantation in 7 mini-swine with coronary sinus angiography and intravascular ultrasound. Histological evaluation was performed at 3 and 6 months. Results Eleven of 12 clinical patients were successfully implanted; 1 procedure was aborted due to challenging coronary sinus anatomy. There were no procedural device-related adverse events. From baseline, a significant improvement in CCS class (3 [3-3] vs 1 [1-1]; P < .001) and in SAQ scores (33.6 ± 13.4 vs 84.5 ± 10.2; P < .001) were observed at the 6-month follow-up. The preclinical experiments had a 100% procedural success rate, with no periprocedural or long-term complications. Histological evaluation showed optimal local tissue response to the CSR with favorable healing characteristics and fully endothelialized, mature neointima around the CSR. All CSR were found to be patent at the time of sacrifice without thrombosis. Conclusions The A-FLUX CSR demonstrates preclinical and clinical procedural safety coupled with promising short-term clinical efficacy in persistently symptomatic patients with both CMD and obstructive CAD.