Coronary sinus reducer (CSR)

Coronary sinus outflow modulation is a physiological intervention achieved through implantation of a coronary sinus reducer device, which narrows the coronary sinus to elevate venous pressure. This leads to an increase in capillary transit time and facilitates redistribution of blood flow from better-oxygenated areas to regions affected by ischemia in the myocardium[1][2][3][5]. The approach is used in treating refractory angina and myocardial ischemia, and its therapeutic rationale is based on the principle: "if you cannot increase coronary input, decrease its output"[1]. This slows the coronary venous drainage, prolongs the exchange of oxygen and nutrients at the microvascular level, and can improve cardiac symptoms and function in eligible patients[1][2][3][5].

Other names

coronary sinus modulationcoronary sinus narrowingcoronary sinus flow modulationcoronary venous pressure augmentationCSR therapy

Increases coronary sinus pressure to slow venous outflow Extends capillary transit time, allowing more time for oxygen and nutrient exchange Redistributes blood from nonischemic to ischemic myocardial regions, improving perfusion especially in severe stenosis