Coronary sinus reducer implantation for refractory angina: a national audit of UK practice

Coronary sinus reducer (CSR) implantation is the only guideline-recommended percutaneous treatment for patients with refractory angina. Data from its real-world large-scale adoption are scarce.

This was a national audit of CSR implanting centres in the UK between November 2014 and 2024. Centres provided data on all patients undergoing clinical CSR implantation through a structured collection template. Data collected included demographics, medical history, medications, angina status, ischaemia testing, procedural characteristics and periprocedural complications. Prespecified endpoints were appropriate patient selection, procedural success and safety, and efficacy of CSR implantation.

19 centres were included capturing 491 patients. Most were male (79%) with high rates of previous myocardial infarction (75%), percutaneous coronary intervention (78%) and coronary artery bypass grafting (69%). Diabetes mellitus (53%), hypertension (76%) and hypercholesterolaemia (78%) were prevalent. 74% had a preserved left ventricular ejection fraction (LVEF≥50%). Patients were severely symptomatic with 84% suffering from Canadian Cardiovascular Society (CCS) class ≥3 angina despite multiple antianginal medications (≥2 drugs 94%; ≥3 drugs 74%). Baseline ischaemia testing was common (79%). Successful CSR implantation was achieved in 95% of cases. 46 periprocedural adverse events (AEs) in 41 patients occurred (9.2%) most commonly due to access complications. Rates of major adverse cardiovascular events and severe AEs were low (<1%). 98% of patients stayed ≤1 night postprocedurally. Significant reductions in CCS class were observed at 6-month follow-up: 75% experienced ≥1 CCS class and 36% ≥2 CCS class angina reduction. Improved angina status was also observed after stratification by age, sex and diabetes mellitus.

This national audit of real-world UK practice confirms CSR implantation is being performed appropriately and safely leading to symptom improvement for patients with refractory angina. Contemporary practice aligns with the recommendations of current guidelines supporting the continued use of CSR in UK clinical practice. Prospective data collection within a national registry is warranted.