Correspondence Letter by Singh Regarding Article, “Berlin Heart EXCOR Pediatric Ventricular Assist Device for Bridge to Heart Transplantation in US Children” To the Editor: The description of the overall Berlin heart EXCOR experience in US children by Almond et al1 is an important contribution to pediatric heart failure literature. After a careful evaluation of baseline factors and competing outcomes in EXCOR recipients, the authors found that reduced end-organ function—renal or hepatic—was independently associated with death after EXCOR implantation. Using the Schwartz equation to estimate glomerular filtration rate (GFR),2 children with a GFR value of 30% to 99% predicted for age were assigned the risk category of “moderate renal dysfunction”1 and were reported to be at higher risk of death after EXCOR compared with children with normal GFR. Although the key message of initiating EXCOR support in children in advanced heart failure before they are too sick is important, it is difficult to accept that either moderate renal dysfunction or the associated mortality risk begins at the GFR value of 99% predicted. Because the normal GFR at any pediatric age is a range of values3,4 and the normal range used in the study (or a reference for such values) was not provided, it is also unclear whether 100% predicted GFR values were the midpoint or the lower end of some range. These details are important for physicians trying to apply this knowledge in patient selection, in determining optimal timing for EXCOR, or in counseling parents regarding the risk benefit of EXCOR implantation in their child. They will also be important for investigators trying to replicate these results or assess risk factors in future cohorts. Determining optimal timing for initiating mechanical support in children with advanced heart failure will be an important area of research in the next decade. The article by Almond et al1 provides significant initial insights.

Disclosures None. Tajinder P. Singh, MD, MSc Department of Cardiology Boston Children’s Hospital Boston, MA

References 1. Almond CS, Morales DL, Blackstone EH, Turrentine MW, Imamura M, Massicotte MP, Jordan LC, Devaney EJ, Ravishankar C, Kanter KR, Holman W, Kroslowitz R, Tjossem C, Thuita L, Cohen GA, Buchholz H, St Louis JD, Nguyen K, Niebler RA, Walters HL III, Reemtsen B, Wearden PD, Reinhartz O, Guleserian KJ, Mitchell MB, Bleiweis MS, Canter CE, Humpl T. Berlin Heart EXCOR pediatric ventricular assist device for bridge to heart transplantation in US children. Circulation. 2013;127:1702–1711. 2. Schwartz GJ, Haycock GB, Edelmann CM Jr, Spitzer A. A simple estimate of glomerular filtration rate in children derived from body length and plasma creatinine. Pediatrics. 1976;58:259–263. 3. Heilbron DC, Holliday MA, al-Dahwi A, Kogan BA. Expressing glomerular filtration rate in children. Pediatr Nephrol. 1991;5:5–11. 4. Hogg RJ, Furth S, Lemley KV, Portman R, Schwartz GJ, Coresh J, Balk E, Lau J, Levin A, Kausz AT, Eknoyan G, Levey AS; National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative. National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative clinical practice guidelines for chronic kidney disease in children and adolescents: evaluation, classification, and stratification. Pediatrics. 2003;111:1416–1421.

(Circulation. 2013;128:e405.) © 2013 American Heart Association, Inc. Circulation is available at http://circ.ahajournals.org

DOI: 10.1161/CIRCULATIONAHA.113.004612

Downloaded from http://circ.ahajournals.org/ ate405 University of Pittsburgh--HSLS on March 9, 2015

Letter by Singh Regarding Article, ''Berlin Heart EXCOR Pediatric Ventricular Assist Device for Bridge to Heart Transplantation in US Children'' Tajinder P. Singh Circulation. 2013;128:e405 doi: 10.1161/CIRCULATIONAHA.113.004612 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2013 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539

The online version of this article, along with updated information and services, is located on the World Wide Web at: http://circ.ahajournals.org/content/128/20/e405

Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Circulation is online at: http://circ.ahajournals.org//subscriptions/

Downloaded from http://circ.ahajournals.org/ at University of Pittsburgh--HSLS on March 9, 2015