Introduction: The coronary sinus Reducer (CSR) device has emerged as a complementary therapy in patients with severe angina refractory to optimal medical therapy and not amenable to revascularization. Our aim was to assess the safety and efficacy of the CSR in a real-world setting. Methods: Twenty-six patients with refractory angina (RA) and evidence of myocardial ischemia attributable to the left coronary arte...