Coronary Sinus Reducer system™: A new therapeutic option in refractory angina patients unsuitable for revascularization

•Epidemiology of Refractory Angina Pectoris.•Anatomo-Pathological Phenotypes of Patients Not Suitable For Myocardial Revascularization.•Alternative Therapies for RAP Patients•Coronary Sinus Reducer System•The device•The Implantation Procedure•Surgical Coronary Sinus Narrowing and Clinical Benefits: First Evidences•Theoretical Patho-physiological Mechanism of Action of the Reducer System•Reducer: Pre-Clinical and Clinical Evidences•Our Experience and Future Directions

A challenge of modern cardiovascular medicine is to find new, effective treatments for patients with refractory angina pectoris (RAP), a clinical condition characterized by severe angina despite optimal medical therapy and “no option” for a surgical or percutaneous revascularization. Although the relevant advance of both pharmaceutical and interventional treatments for patients affected by symptomatic coronary artery disease has greatly contributed to prolong survival, the increasing number of patients experimenting persistent and invalidating angina symptoms, highlights that quality of life of these patients has not been equally improved. Clinical limitations of the efficiency of conventional and relatively new approaches justify the search for new therapeutic options.In this review, we will focus on the epidemiology of RAP, and we will provide a brief update on the different options actually available to these patients with particular interest to an innovative device that narrow the coronary sinus: the Reducer system (Neovasc Inc., Richmond B.C., Canada). The efforts of present and future clinical studies will ultimately answer the question of whether this intriguing therapy is a suitable strategy for treatment of patients with RAP.