Thomas G Wilson1,2, Yves d'Udekem1,2,3, David S Winlaw4,5, Rachael L Cordina5,6, Julian Ayer4,5, Thomas L Gentles7, Robert G Weintraub1,2,8, Leeanne E Grigg9, Michael Cheung1,8, Timothy M Cain10, Padma Rao10, Charlotte Verrall4, Karin Du Plessis1, Kathryn Rice7, Ajay J Iyengar1,3. 1. Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia. 2. Department of Paediatrics, Faculty of Medicine, The University of Melbourne, Melbourne, Victoria, Australia. 3. Department of Cardiac Surgery, The Royal Children's Hospital, Melbourne, Victoria, Australia. 4. The Heart Centre for Children, The Children's Hospital at Westmead, Sydney, New South Wales, Australia. 5. Department of Paediatrics, University of Sydney, Sydney, New South Wales, Australia. 6. Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia. 7. Greenlane Paediatric and Congenital Cardiac Service, Starship Children's Hospital, Auckland, New Zealand. 8. Department of Cardiology, The Royal Children's Hospital, Melbourne, Victoria, Australia. 9. Department of Cardiology, The Royal Melbourne Hospital, Melbourne, Victoria, Australia. 10. Medical Imaging Department, The Royal Children's Hospital, Melbourne, Victoria, Australia.
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 glomerular 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 99m Tc-DTPA clearance was performed. Various serum creatinine-based equations were used to calculate estimated GFR (eGFR). RESULTS: Mean mGFR was 108 ± 28 mL/min/1.73 m2 in children and 92 ± 20 mL/min/1.73 m2 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90 mL/min/1.73 m2 . 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 m2 , 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 m2 , 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), however, both methods overestimated mGFR (eGFR(CKD-EPI):bias 23.8, 95%CI: 20-27.6 mL/min/1.73 m2 , P < .0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8-20.4 mL/min/1.73 m2 , P < .0001). None of the children with an mGFR <90 mL/min/1.73 m2 had an eGFR (Schwartz) <90 mL/min/1.73 m2 . Sensitivity and specificity of eGFR (CKD-EPI) and eGFR (MDRD) for mGFR <90 mL/min/1.73 m2 in adults were 25% and 92% and 39% and 100%, respectively. CONCLUSIONS: This study identifies the unreliability of using creatinine-based equations to estimate GFR in children with a Fontan circulation. The accuracy of formulas incorporating cystatin C should be further investigated and may aid noninvasive surveillance of renal function in this population.
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 glomerular 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 99m Tc-DTPA clearance was performed. Various serum creatinine-based equations were used to calculate estimated GFR (eGFR). RESULTS: Mean mGFR was 108 ± 28 mL/min/1.73 m2 in children and 92 ± 20 mL/min/1.73 m2 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90 mL/min/1.73 m2 . 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 m2 , 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 m2 , 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), however, both methods overestimated mGFR (eGFR(CKD-EPI):bias 23.8, 95%CI: 20-27.6 mL/min/1.73 m2 , P < .0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8-20.4 mL/min/1.73 m2 , P < .0001). None of the children with an mGFR <90 mL/min/1.73 m2 had an eGFR (Schwartz) <90 mL/min/1.73 m2 . Sensitivity and specificity of eGFR (CKD-EPI) and eGFR (MDRD) for mGFR <90 mL/min/1.73 m2 in adults were 25% and 92% and 39% and 100%, respectively. CONCLUSIONS: This study identifies the unreliability of using creatinine-based equations to estimate GFR in children with a Fontan circulation. The accuracy of formulas incorporating cystatin C should be further investigated and may aid noninvasive surveillance of renal function in this population.
Authors: Peter Kramer; Anastasia Schleiger; Marie Schafstedde; Friederike Danne; Johannes Nordmeyer; Felix Berger; Stanislav Ovroutski Journal: Front Cardiovasc Med Date: 2022-03-10