@Article{chd.12746,
AUTHOR = {Thomas G. Wilson, Yves d’Udekem, David S. Winlaw, Rachael L. Cordina, Julian Ayer, Thomas L. Gentles, Robert G. Weintraub, Leeanne E. Grigg, Michael Cheung, Timothy M. Cain, Padma Rao, Charlotte Verrall, Karin Du Plessis, Kathryn Rice, Ajay J. Iyengar},
TITLE = {Creatinine‐based estimation of glomerular filtration rate in patients with a Fontan circulation},
JOURNAL = {Structural and Congenital Heart Disease},
VOLUME = {14},
YEAR = {2019},
NUMBER = {3},
PAGES = {454--463},
URL = {http://www.techscience.com/schd/v14n3/38791},
ISSN = {3071-1738},
ABSTRACT = {Background: Patients with a Fontan circulation are at risk of renal dysfunction. We 
analyzed cross‐sectional data in pediatric and adult Fontan patients in order to assess 
the accuracy of commonly used serum creatinine‐based methods in estimating glo‐
merular filtration rate (GFR).
Methods: A total of 124 Fontan patients (58 children, 66 adults) were enrolled across 
three study centers. Measurement of GFR (mGFR) using in vivo <sup>99m</sup>Tc‐DTPA clear‐
ance was performed. Various serum creatinine‐based equations were used to calcu‐
late estimated GFR (eGFR).
Results: Mean mGFR was 108 ± 28 mL/min/1.73 m<sup>2</sup>
 in children and 92 ± 20 mL/
min/1.73 m<sup>2</sup>
 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90 mL/min/1.73 m<sup>2</sup>
. There was no significant correlation between mGFR and eGFR 
(Schwartz) in children (r = 0.22, P = .1), which substantially overestimated mGFR (bias 
50.8, 95%CI: 41.1‐60.5 mL/min/1.73 m<sup>2</sup>
, P < .0001). The Bedside Schwartz equation 
also performed poorly in the children (r = 0.08, P = .5; bias 5.9, 95%CI: −2.9‐14.6 mL/
min/1.73 m<sup>2</sup>
, P < .0001). There was a strong correlation between mGFR and both 
eGFR (CKD‐EPI) and eGFR (MDRD) in adults (r = 0.67, P < .0001 in both cases), how‐
ever, both methods overestimated mGFR (eGFR(CKD‐EPI):bias 23.8, 95%CI: 
20‐27.6 mL/min/1.73 m<sup>2</sup>
, P < .0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8‐20.4 mL/
min/1.73 m<sup>2</sup>
, P < .0001). None of the children with an mGFR <90 mL/min/1.73 m<sup>2</sup>
had an eGFR (Schwartz) <90 mL/min/1.73 m<sup>2</sup>
. Sensitivity and specificity of eGFR 
(CKD‐EPI) and eGFR (MDRD) for mGFR <90 mL/min/1.73 m<sup>2</sup>
 in adults were 25% and 
92% and 39% and 100%, respectively.
Conclusions: This study identifies the unreliability of using creatinine‐based equa‐
tions to estimate GFR in children with a Fontan circulation. The accuracy of formulas 
incorporating cystatin C should be further investigated and may aid noninvasive sur‐
veillance of renal function in this population.},
DOI = {10.1111/chd.12746}
}