HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Electronic Letters to:

Invited Review: Ghassan S. Kassab, Jose A. Navia, Keith March, and Jenny S. Choy Coronary Venous Retroperfusion: An Old Concept, a New Approach J Appl Physiol 2008; 0: 00063.2008v1 [Abstract] [PDF]

eLetters: Submit a response to this article

Electronic letters published:

The clinical potential of coronary sinus interventions

Werner Mohl, Guenter Weigel, Stefan Mina and Hirofumi Kasahara   (16 July 2008)

Auto-Retroperfusion or PICSO? What the heart really needs is oxygen!

Ghassan S. Kassab, Jose A Navia (Austral University)   (11 June 2009)

The clinical potential of coronary sinus interventions 16 July 2008
Werner Mohl, MD,PhD Medical University of Vienna, Guenter Weigel, Stefan Mina and Hirofumi Kasahara Send letter to journal: Re: The clinical potential of coronary sinus interventions werner.mohl{at}meduniwien.ac.at Werner Mohl, et al.	We read with interest the review on retroperfusion concepts recently published by Kassab and colleagues (4). Although this article gives a good overview on the topic some parts are missing or misinterpreted. Especially the notion that autoperfusion is a new concept is much to our surprise. Instead we believe that the current concept of autoperfusion is a sophisticated interventional reproduction of the Beck´s II procedure. As known this operation involved a narrowing of the coronary sinus and subsequent closure with shunting of arterial blood through a saphenous graft from the descending aorta to the coronary veins. This implements that pressure as well as arterialisation of blood has effects on the coronary venous system. In a meta-analysis Syeda (1) reported on the effects of different coronary sinus interventions on infarct size reduction. In her paper she was able to show a negative relationship between the amount of retroperfused blood and salvage and a positive relationship with developed coronary sinus pressure discriminating the concepts of retroperfusion of arterial blood and coronary sinus pressure elevation. Weigel (2) and colleagues reported recently on another very important consequence of coronary sinus techniques namely the activation of endothelium and subsequent molecular cascades obviously leading to regeneration. Therefore we feel that this overview on retroperfusion techniques only reporting on coronary venous arterialisation leaves out an important part of the pathophysiology of coronary sinus interventions. Furthermore the proposed autoperfusion techniques have to be balanced and justified against less invasive concepts like PICSO in translational research, since recently published data on this technology show interesting results on infarcts size reduction and clinical significance (3). Overall we are in complete agreement with the authors that coronary sinus techniques have an unexplored clinical potential which has to be analysed with outmost scientific scrutiny and state of the art technology. References 1. Syeda B, Schukro C, Heinze G, et al. The salvage potential of coronary sinus interventions: meta-analysis and pathophysiologic consequences. J Thorac Cardiovasc Surg 2004;127(6):1703-12. 2. Weigel G, Kajgana I, Bergmeister H, et al. Beck and back: a paradigm change in coronary sinus interventions--pulsatile stretch on intact coronary venous endothelium. J Thorac Cardiovasc Surg 2007;133(6):1581-7. 3. Mohl W, Komamura K, Kasahara H, et al. Myocardial protection via the coronary sinus. Circ J 2008;72(4):526-33. 4. Kassab GS, Navia JA, March K, and Choy JS. Coronary venous retroperfusion: an old concept, a new approach. J Appl Physiol, May 2008; 104: 1266 - 1272.
Auto-Retroperfusion or PICSO? What the heart really needs is oxygen! 11 June 2009
Ghassan S. Kassab, Department of Biomedical Engineering, Surgery, and Cellular and Integrative Physiology IUPUI, Indianapolis, Jose A Navia (Austral University) Send letter to journal: Re: Auto-Retroperfusion or PICSO? What the heart really needs is oxygen! gkassab{at}iupui.edu Ghassan S. Kassab, et al.	We thank Mohl for his interest in our review and for his appraisal. He questioned the novelty of our proposed percutaneous selective auto- retroperfusion (ARP) approach and underscored PICSO as a translational approach. We hope to clarify both issues and to talk about what really matters for the heart! Percutaneous selective ARP using a pressure-moderating catheter for acute MI or for chronic no-option patients (with pre-arterialization of venous system) is novel (1). The Beck two-step procedure on the coronary sinus was devised to pre-arterialize the veins but inevitably congested the venous system. There are several key differences worthy of note: 1) selective rather than coronary sinus ARP that allows venous drainage to prevent venous congestion (3), 2) a percutaneous approach rather than open surgery, and 3) a single interventional procedure with a pressure- regulating catheter instead of two surgical procedures using a graft. Although the pioneering work of Beck stimulated much interest in this area, it did not receive clinical acceptance because of these shortcomings. The ischemic myocardium requires delivery of oxygen and nutrients and removal of metabolic byproducts. PICSO is a percutaneous approach with a pulsating balloon placed in the coronary sinus (CS) driven by an external pump. The increase in CS pressure is likely to have several effects including: 1) a pressure gradient to drive venous blood to the region of ischemia, 2) increase in transit time of blood which may increase oxygen extraction and 3) potential distension of post-capillary venules which may enhance waste removal. ARP has all the same benefits of PICSO because it also leads to pressure elevation but it has an additional distinct and critical advantage to PICSO: Oxygen delivery. The ischemic, stunned or hibernating myocardium requires oxygen and simply redirecting oxygen- depleted venous blood to those regions remains questionable. Furthermore, it is unclear how an acute (hours) implementation of PICSO can lead to any longterm regeneration suggested by Mohl and colleagues (2). Genes and molecules can be upregulated in hours but cells and tissues “regeneration” (e.g., angiogenesis, arteriogenesis, remodeling, etc.) requires much longer periods of mechanical stimulation. We can all agree that any translational approach has to be simple. The utility of devices that require external pumps for balloon pulsation and synchronization adds complexity. The strength of percutaneous ARP is the lack of need for an external pump. The heart is the ideal pump and synchronizing myocardial perfusion with arterial blood is most in line with coronary physiology. The regulation of pressure to the venous system through the catheter circumvents the major issue with ARP (i.e., it eliminates the hemorrhage that results from exposing the venous system to the full arterial pressure). Another point of agreement is that this type of dialogue about potential new clinical reperfusion approaches to stop negative remodeling of myocardium and heart failure are vital. We hope that this continues and that practical, effective and safe treatments, that have a basis in physiology, can emerge to reduce mortality and morbidity of MI and to impact the epidemic of heart failure. References 1. Kassab GS, Navia JA, March K, and Choy JS. Coronary venous retroperfusion: an old concept, a new approach. J Appl Physiol, 104: 1266–1272, 2008. 2. Weigel G, Kajgana I, Bergmeister H, et al. Beck and back: a paradigm change in coronary sinus interventions--pulsatile stretch on intact coronary venous endothelium. J Thorac Cardiovasc Surg 133(6):1581- 7, 2007. 3. Choy, JS and G.S. Kassab. A novel strategy for increasing wall thickness of coronary venules prior to retroperfusion. Am J Physiol Heart Circ Physiol. 291(2): H972-8, 2006.