Refractory angina due to advanced obstructive coronary artery disease (CAD) remains a major clinical problem with limited evidence-based treatment options. The coronary sinus reducer (CSR) is an hourglass-shaped stainless-steel mesh device designed to create a controlled narrowing of the coronary sinus (CS). By increasing CS pressure, CSR implantation may improve myocardial perfusion and reduce anginal symptoms, although the physiological mechanisms underlying this effect remain incompletely understood.
REDUCE-ANGINA is a prospective observational study investigating the hemodynamic effects of CSR implantation in 25 patients with refractory angina and advanced CAD. The study evaluates the interaction between coronary sinus hemodynamics and coronary arterial blood flow before and after CSR implantation. The main study endpoints include changes in coronary sinus pressure, coronary flow reserve, microvascular resistance reserve, and absolute microvascular resistance from baseline to 6 months, measured using continuous flow thermodilution during saline-induced coronary hyperemia.