Gastro-intestinal protein loss in late survivors of Fontan surgery and other congenital heart disease

Aims Protein losing enteropathy is a serious complication of Fontan surgery. The aim of this study was to investigate gastro-intestinal protein loss in adults with congenital heart disease, both with and without Fontan surgery, and to correlate findings with systemic venous pressure. Methods and Results Forty eight patients were studied. The first group included adult survivors of Fontan surgery. The second and third groups were control patients with congenital heart disease who had not had Fontan surgery and had either normal or chronically elevated systemic venous pressure. Gastro-intestinal protein loss was assessed by measurement of faecal alpha-1-antitrypsin. Faecal alpha-1-antitrypsin levels were significantly higher in the Fontan group (0.55+/-0.15 mg.g(-1) faeces, P=0.002) and the control group with chronically elevated venous pressure (0.60+/-0.30 mg.g(-1) faeces, P=0.001) compared to the controls with normal venous pressure (0.29+/-0.12 mg.g(-1) faeces). Of the 15 subjects who were found to have increased gastro-intestinal protein loss, only four had clinical protein-losing enteropathy. The degree of gastro-intestinal protein loss correlated significantly with venous pressure (P=0.01) and with serum aspartate transaminase (P=0.04). Conclusion Increased gastro-intestinal protein loss is common in this select group of late survivors of Fontan surgery and in other subjects with congenital heart disease and chronic elevation of systemic venous pressure, and was present in patients who did not have protein-losing enteropathy. Increased faecal alpha-1-antitrypsin is an important finding in these patients as intervention at this stage, before the onset of florid protein-losing enteropathy, might prevent the development of further complications.