Assessment of Kidney Function in Survivors Following Fontan Palliation

Abstract

Ten percent of long-term survivors post-Fontan palliation had eGFR <90 ml/min/1.73 m , and higher median parathyroid hormone levels compared to controls. Taken together, these measures may indicate early kidney disease. Future studies will focus on longitudinal assessment of kidney function and evaluation of risk factors for CKD post-Fontan palliation.

Estimated glomerular filtration rate and urine biomarkers in patients with single-ventricle Fontan circulation

“…Our findings support previous reports that microalbuminuria or at least trace dipstick proteinuria is prevalent in patients with a Fontan circulation 7 21. This is concerning in the context of extensive evidence that microalbuminuria predicts adverse cardiovascular outcomes in patients with various underlying disease as well as in the general population.…”

“…These values likely underestimate the prevalence of importantly low GFR since we excluded patients with known clinical kidney disease. A recent study of patients following Fontan palliation, including mainly paediatric patients, similarly reported that 10.3% of the 68 patients had GFR<90 mL/min/1.73 m 2 21. While each estimating equation suggested a similar proportion of patients with reduced GFR, cystatin C estimates suggested an overall distribution shift toward lower GFR while the creatinine-based approach did not.…”

Renal dysfunction is associated with higher central venous pressures in patients with Fontan circulation

“…Glomerular filtration is a key component of kidney function and partially depends on venous pressure; and therefore, it is not surprising venous congestion/high CVP alters kidney function. Venous congestion is innate in the Fontan circulation and many investigators have long suspected potential deleterious long‐term effects on the kidneys . Thus far, renal dysfunction related to venous congestion and high CVP have principally been described in the context of (right) heart failure …”

“…Renal function is significantly dependent on a favorable preglomerular and postglomerular pressure gradient, and therefore, may be affected in patients with Fontan circulation. Indeed, there is a growing body of evidence supporting the hypothesis that the hemodynamic effects of the Fontan circulation may adversely affect kidney health . In this study, we sought to evaluate relationship of CVP and estimated glomerular filtration rate (eGFR) in the patients with Fontan circulation.…”

Creatinine‐based estimation of glomerular filtration rate in patients with a Fontan circulation

“…1 The focus in these patients is now shifting to the extracardiac manifestations resulting from this unique physiological state, characterized by elevated venous pressures and a reduced cardiac output. 5 Data are emerging on the use of cystatin C-based equations in Fontan patients, which may more accurately reflect true GFR in the Fontan cohort when compared to creatinine-based equations, possibly due to reduced lean muscle mass in these patients. 2, 3 We now know that up to half of adult Fontan patients will have evidence of chronic kidney damage in the form of a reduced measured glomerular filtration rate (mGFR) <90 mL/min/1.73 m. 2, 4 It is likely that renal dysfunction will go undetected for some time in many Fontan patients, which may be partly due to the overestimation of GFR using serum-based formulas, and a lack of consensus on the best methods of surveillance.…”