Renal impairment in patients with long-standing cyanotic congenital heart disease

Abstract

Nephropathy is known to occur in patients with long-standing cyanotic congenital heart disease (CCHD). In order to assess the incidence, nature and degree of the problem among such patients, discriminating urine analyses were performed in 26 patients with CCHD, with a mean age of 22 (10-42) y. Ten patients showed reduced glomerular function, six of whom also had advanced glomerulopathy. Glomerular filtration rates were below normal in half of the patients and occurred with glomerular-type proteinuria in five, with tubular-type proteinuria in one and without pathological proteinuria in four. An elevated haematocrit and duration of cyanosis were identified as the main risks factors for the development of glomerulopathy. The risk of developing glomerular lesions rose sharply during the second decade of life. Nephropathy in CCHD is common and the dominant feature is glomerular damage, which is related to the duration of cyanosis and the extent to which the haematocrit is elevated.

Effect of Congenital Heart Disease on Renal Function in Childhood

“…Tubular damage was diagnosed on the basis of maximum cut-off values of 1,244 U/mol for NAG/creatinine and/or 40.7 mg/mol for β 2 -microglobulin/creatinine [2, 13, 14]. The maximum cut-off values were accepted to be 1% for FeNa and 1.17 g/mol for albumin/creatinine [13, 14].…”

“…Most studies of renal impairment in CHD have been conducted on patients in the second decade of life and older [1, 2, 3, 5]. The aim of this study was to investigate the effect of congenital heart disease on renal function in younger children, and compare findings in cyanotic and acyanotic groups.…”

“…Several studies have documented proteinuria, decreased renal blood flow, and decreased glomerular filtration rate in patients with CHD; however, only a few reports have discussed renal tubular dysfunction in this group [2, 6, 7]. …”

“…Chronic hypoxia stimulates the release of erythropoietin, which boosts erythrocyte production and thus increases blood volume and viscosity [2]. Hypoxia has been shown to induce proliferation of renal tubular and glomerular cells, changes that are part of the pathogenesis of renal injury [4].…”

“…Nephropathy is a well-known complication of congenital heart disease (CHD), and the risk of developing renal impairment is particularly high in patients with cyanotic CHD [1, 2, 3]. Chronic hypoxia stimulates the release of erythropoietin, which boosts erythrocyte production and thus increases blood volume and viscosity [2].…”