Nephropathy of cyanotic congenital heart disease: clinical characteristics and effectiveness of an angiotensin-converting enzyme inhibitor

Abstract

Nephropathy has long been recognized as a potential complication of cyanotic congenital heart disease (CCHD). There have been few large-scale studies or clinical reports on renal impairment in patients with CCHD; similarly, very few studies have examined the drug treatment of nephropathy in CCHD. We examined the clinical characteristics and effectiveness of enalapril, an angiotensin-converting enzyme inhibitor (ACE-I), in patients with CCHD complicated with significant proteinuria. The clinical records of 37 patients with CCHD were evaluated; all were older than 10 years of age (median 19, range from 10 to 27) and had regular check-ups, including urinalysis. The treatment criteria for enalapril administration included significant proteinuria (urinary excretion > 1.0 g/24 h), stable cardiac condition and blood pressure within the normal range. Eleven patients (29.7%) had persistent proteinuria, 6 patients met the enalapril treatment criteria and 5 patients were treated for more than 12 months. Enalapril apparently reduced the urinary protein excretion in 4 of the 5 patients (80%). No consistent improvement of renal function, as evidenced in the glomerular filtration rate (GFR), renal plasma flow (RPF) or filtration fraction (FF) was found in these patients, but neither were any significant adverse effects noted. The incidence of nephropathy among patients with CCHD was about 30%, which was consistent with previous studies. It is worth considering the use of ACE-I when nephropathy accompanies CCHD.