Efficacy of Coronary Sinus Reducer in Patients With Nonrevascularized Chronic Total Occlusions: A Multicenter Experience

Background The use of a Coronary Sinus Reducer (CSR) device (Neovasc Inc., Richmond, BC, Canada) has recently been introduced in the treatment of refractory angina not amenable to alternative medical or interventional options with reported promising benefits in terms of symptom relief. Data regarding the specific use of CSR in patients with documented chronic total occlusion (CTO) not amenable for both surgical and percutaneous revascularization are still lacking. Methods In this prospective and multicenter registry, we describe the clinical outcome of patients with nonrevascularized CTO lesions undergoing CSR implantation between January 2014 and December 2018. Indication for CSR implantation included age >18 years, obstructive coronary artery disease with chronic refractory angina, and Canadian Cardiovascular Society (CCS) grade II to IV despite maximally tolerated antianginal medical therapy for at least 30 days before screening. Patients were divided into 2 groups according to the presence/absence of CTO at baseline angiography. Clinical outcome was defined as improvements in CCS. Results A total of 205 patients were consecutively treated with the study device in the participating centers. In 103 (50.2%) of these cases, the indication to the CSR was determined by the presence of a CTO not favorable for revascularization procedures (74 [71.8%]) or with at least 1 previous failed attempt of percutaneous recanalization (29 [28.1%]). Baseline characteristics of the study population were well balanced between the 2 groups, including baseline CCS. At a median follow-up of 1.8 years, mean CCS class was 1.6 ± 0.9 in patients with a CTO at baseline versus 2 ± 1.1 in those without, with significantly higher improvement in CCS class in the CTO group (1.4 ± 0.9 vs. 1.1 ± 1, respectively; p = 0.01). Similar incidences of adverse clinical events were reported in the 2 study groups. Complete data regarding the clinical and procedural outcome will be provided in a definitive version upon acceptance. Conclusion According to our findings, the adoption of the CSR in patients with evidence of CTO experiencing refractory angina yields promising results in terms of symptom relief and can be considered a valid alternative in cases of CTO-PCI failure.