Vascular Health and Risk Management Open Access Full Text Article Dovepress open access to scientific and medical research L e T T e R Coronary sinus intervention for the treatment of refractory angina pectoris Yoav Paz1,3 Amihay Shinfeld2,3 1General Intensive Care Unit, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; 2Department of Cardiac Surgery, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv, Israel; 3Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Correspondence:Yoav Paz General Intensive Care Unit,Tel Aviv Sourasky Medical Center, 6 Weizman St, Tel Aviv 64239, Israel email pazyoav@bezegint.net We read with great interest the article “Recent advances in the management of chronic stable angina II. Anti-ischemic therapy, options for refractory angina, risk factor reduction, and revascularization” by Dr Richard Kones.1 Dr Kones presents an excellent review in which he describes some invasive anti-anginal therapies for the treatment of those ill-fated patients who suffer from refractory angina pectoris (RAP), a type of angina pectoris that persists despite optimal medical therapy, in patients who are not candidates for revascularization. Dr Kones discusses five invasive antianginal therapies for refractory angina: spinal cord stimulation, enhanced external counterpulsation, transmyocardial laser revascularization, stem cell/gene therapy, and percutaneous coronary intervention (PCI), all of which are options for a selected group of patients only. However, one emerging innovation for the treatment of patients suffering from RAP has been overlooked, namely that of coronary sinus intervention. We would like to add a comment to Dr Kones’ excellent review and present some historical facts and medical information about the Neovasc coronary sinus reducer stent (CSRS) for the treatment of patients with RAP who are not candidates for coronary artery revascularization, either coronary artery bypass grafting or PCI. In the mid 1990s we initiated an unusual, novel approach to support the ischemic myocardium, which we called “the upside-down strategy”. This means we initially catheterized the coronary venous system instead of the coronary arteries, arriving at the coronary sinus, and secondly reduced the coronary sinus effective cross area instead of expanding a narrowed coronary artery. We were very surprised with the results of our initial studies in pig models, since we noticed that permanent constriction of the coronary sinus caused some kind of epicardial and intramyocardial neovascularization/angiogenesis of medium- size blood vessels, compared with untreated pigs. These new or dormant blood vessels could be seen even at the macroscopic level. Following several developmental stages, we produced the first percutaneous intravenous CSRS, which we called “Neovasc”, and which later became known as Neovasc Medical, Inc (Richmond, Canada). The CSRS is a balloon-expandable stent, implanted by a percutaneous transvenous approach through the right internal jugular vein or any other large peripheral vein. It has a unique shape that reduces the coronary sinus diameter to 3 mm, thereby reducing, rather than increasing, coronary circulation output. The first human study, a prospective, open-labeled, safety feasibility study, began in 2004.2 The CSRS was implanted in 15 patients with angina pectoris refractory submit your manuscript | www.dovepress.com Dovepress DOI: 10.2147/VHRM.S15808 Vascular Health and Risk Management 2011:7 135–136 135 © 2011 Paz and Shinfeld, publisher and licensee Dove Medical Press Ltd.This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited.