The renal effects of radiocontrast administration during cardioangiography in two different groups with congenital heart disease

Renal effects of the administration of contrast media during cardiac catheterisation were compared in two groups of patients with congenital heart diseases. Group A consisted of 21 patients with cardiac malformations, characterised primarily by left ventricular valvular defects. Group B consisted of 23 patients with lesions affecting the right ventricle which are rarely associated with left heart failure, such as: Tetralogy of Fallot and Pulmonic stenosis. Patients in Group A showed a significant increment in both plasma creatinine and uric acid levels in the 24 h following heart catheterisation. This observation was significantly more prominent in the older age group (above the age of 5 years). In Group B no changes in these parameters were encountered. Plasma renin activity and fractional sodium excretion increased and decreased respectively, by a similar degree in both groups in the 24h following contrast media administration. No difference in renal tubular handling of uric acid was observed between both groups, nor did any of the patients studied demonstrate any degree of proteinuria or abnormality in the urine sediment, prior to or following heart catheterisation. We suggest that chronic pre-existing left ventricular overload should be considered a risk factor among the other known risk factors which promote the incidence of acute renal failure after contrast media administration. We also suggest that the reduction in glomerular filtration rate as evidenced in Group A by the increase in plasma creatinine and uric acid levels could be attributed to indirectly renin-mediated changes in systemic haemodynamics, probably induced by the high osmotically active contrast media. Patients with chronic pre-existing left ventricular volume overload are probably more prone to develop transient cardiac decompensation due to the transient hyper-osmolar state caused by the contrast media and which results in renal function impairment. Older children who have longstanding left ventricular overload are more prone to develop this transient cardiac decompensation, resulting in renal function impairment, than younger ones with the same cardiac lesions.