Renal Dysfunction is Common Among Adults After Palliation for Previous Tetralogy of Fallot

Abstract

Long-term survival after tetralogy of Fallot (TOF) repair is excellent. However, little is published regarding late noncardiac complications. This study aimed to determine the prevalence and risk factors for renal dysfunction among adults after TOF repair. For this study, 56 adult patients with complete repair of TOF were identified, and their charts were retrospectively reviewed. An estimated glomerular filtration rate (eGFR) for each patient was calculated using the Modification of Diet in Renal Disease formula (MDRD). Using each patient's eGFR, he or she was classified into stages based on the National Kidney Foundation chronic kidney disease (CKD) staging. Clinical parameters were compared among patients with and those without renal dysfunction to identify risk factors for renal impairment. The median estimated eGFR rate for the cohort was 78 ml/min/1.73 m(2). Based on the National Kidney Foundation CKD staging system, 54 % of the patients had at least stage 2 chronic renal disease. The risk factors identified were hypertension (p < 0.01), type 2 diabetes mellitus (p < 0.05), longer follow-up evaluation (p < 0.005), older age at complete repair (p < 0.05), and use of daily diuretics (p < 0.05). After repair of TOF, renal dysfunction is common at late follow-up evaluation. The study findings show the importance of routine assessment of renal function and the need to limit or avoid future episodes of acute kidney injury in this at-risk population.

Congenital Heart Disease in the Older Adult

“…Furthermore, the rate of decline of renal function was more rapid in the palliated TOF cohort than in the general population. 204 Renal function was worse in adults who had more complex CHD, particularly those with cyanotic heart disease. Compared with the general population, renal dysfunction in the ACHD population has been found to be 18-fold higher in acyanotic patients and 35-fold higher in cyanotic patients.…”

“…201 Cyanosis is thought to affect renal function both directly via chronic hypoxia and ischemia and indirectly through erythrocytosis and increased blood viscosity, which can affect glomerular arteriolar resistance, filtration, and renal perfusion. 203,204 Other important risk factors for renal dysfunction in the ACHD population relate to multiple cardiac surgeries that require CPB. Clinically relevant renal injury develops in ≈30% of cardiac surgery patients.…”

“…205 Other potential causes of renal dysfunction in the ACHD patient include traditional risk factors such as hypertension, diabetes mellitus, cardiac dysfunction, advancing age, and use of diuretic drugs and nephrotoxic medications (including contrast agents during prior catheterizations and CT scans). [203][204][205] Increased central venous pressure has been shown to be associated with impaired renal function in various cardiovascular diseases 208 and to be an important hemodynamic factor behind worsening renal function in patients with decompensated heart failure. 209 Because increased central venous pressure is a common finding in many forms of CHD, this may play an important role in renal dysfunction in the ACHD population.…”

Extracardiac Complications in Adults with Congenital Heart Disease

“…Furthermore, the rate of decline of renal function is more rapid in the palliated tetralogy of Fallot cohort compared to the general population. 37 Renal function is worse in adults that have more complex CHD; particularly in cyanotic heart disease. When compared with the general population, renal dysfunction in the ACHD population has been found to be 18-fold higher in noncyanotic patients and 35-fold higher in cyanotic patients.…”

“…Cyanosis is thought to affect renal function both directly via chronic hypoxia and ischemia; but also indirectly through erthrocytosis and increased blood viscosity that can affect glomerular arteriolar resistance, filtration, and renal perfusion. 36,37 Other important risk factors for renal dysfunction in the ACHD population relate to multiple cardiac surgeries requiring cardiopulmonary bypass (CPB). Clinically relevant renal injury develops in approximately 30% of cardiac surgery patients.…”