The coronary sinus reducer for the treatment of refractory angina

We were very interested to read the recently published manuscript ‘Safety and efficacy of a device to narrow the coronary sinus for the treatment of refractory angina: A single-centre real-world experience’ by Masieh Abawi et al. [1]. Some people make a mistake and compare the coronary sinus reducer (CSR) with the Beck procedure (Beck operation), but actually the Beck procedure has almost nothing in common with the CSR. In the 1940s, Dr Claude Beck described two types of coronary sinus (CS) interventions [2, 3]. The Beck I procedure consisted of the following steps: 1) abrading of both epicardium and inner pericardium. Dr Beck explained that it produces mechanical trauma, which in turn causes inflammation and intercoronary arterial channels. 2) spilling of powdered asbestos and 5% aqueous trichloracetic acid on the epicardium. Dr Beck explained that this produces chemical trauma, which in turn also results in inflammation and intercoronary arterial channels. 3) CS constriction to a diameter of 3 mm. The Beck II procedure consisted of a vascular graft between the descending aorta and the CS followed by operative external constriction of the CS ostium a few weeks later. Both procedures needed thoracot-