Clinical outcome of coronary sinus reducer in refractory angina: A prospective real-world observational study

Coronary sinus reducer (CSR) is an emerging therapeutic invasive treatment option that can improve refractory angina symptoms. However, access to this service in the UK remains largely restricted to tertiary centres.

To assess patient outcomes, procedural safety and feasibility of establishing a CSR service in a UK district general hospital (DGH) without on-site surgical back-up.

A total of 27 consecutive patients with refractory angina underwent CSR implantation between October 2023 and March 2025. Angina severity and functional status were assessed using the Seattle Angina Questionnaire (SAQ) or Canadian Cardiovascular Society (CCS) class, prior to and 6-months after CSR implantation. The primary endpoint was improvement of SAQ score by at least 10 points or CCS class by ≥1 at 6-months follow-up. Secondary endpoints were procedural success, periprocedural and in-hospital MACE, and major bleeding.

Procedural success was achieved in 96.4% of the patients. No major peri-procedural complications were reported. The mean SAQ score improved significantly from 53.2±15.8 at baseline to 62.0±15.8 at 6-month follow-up (p=0.005). The median CCS class decreased from 3 (IQR 3-3) at baseline to 2 (IQR 1-2) (p<0.001), with 75.0% of evaluable patients improving by at least one CCS class. Significant improvement was most pronounced in Angina Frequency (57.8±21.7 vs. 72.2±21.4 at 6-month, p<0.001), and Angina Stability (39.6±27.7 vs. 60.4±28.2 at 6-month, p=0.005), which subsequently led to improvement in Physical Limitation (43.9±18.8 vs. 52.2±21.3 at 6-month, p=0.020), CONCLUSION: CSR implantation led to improvement of quality-of-life at 6-months follow-up. This service can be delivered safely and effectively within a DGH setting, with outcomes comparable to tertiary centres. Our data supports that post-CSR implantation same-day discharge is both safe and cost-effective.