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

Are My Pediatric Patients at Increased Risk of Developing Chronic Kidney Disease?

Chronic kidney disease (CKD) is an underrecognized and often undiagnosed cause of morbidity and mortality. Many children and adolescents are at increased risk of developing CKD as they mature and age, secondary to conditions commonly cared for by pediatric health professionals. Prematurity, diabetes mellitus, hypertension, congenital heart disease, sickle cell disease and trait, severe obesity, cancer chemotherapy, other drug toxicities, and systemic situations that may cause acute kidney injury such as sepsis or extracorporeal membrane oxygenation therapy predispose to potential CKD. Clinicians should be aware of these conditions in order to screen for CKD, choose non-nephrotoxic treatments for these children whenever possible, and treat or refer those who have early signs of CKD.

Prevalence and associated factors of renal dysfunction and proteinuria in cyanotic congenital heart disease

BACKGROUND

Cyanotic nephropathy (CN), seen in 30-50% of patients with congenital cyanotic heart disease (CCHD), affects both tubular and glomerular function, resulting in proteinuria and azotemia. Microalbuminuria is an early marker for glomerular damage and an independent predictor of progressive renal disease.

METHODS

A cross-sectional study was conducted. A total of 116 patients aged 1 month to 15 years with CCHD at Chiang Mai University Hospital between 2015 and 2016 were assessed and 94 patients were enrolled. To determine the prevalence and associated factors of significant albuminuria in CCHD patients, baseline characteristics, oxygen saturation, surgery, hemoglobin (Hb), hematocrit (Hct), spot urine albumin, urine protein, and creatinine were obtained. Binary logistic-regression modeling was used to identify associated factors.

RESULTS

Prevalence of CN in children with CCHD was 58.51% and 92.55% according to albuminuria and proteinuria staging respectively. Prevalence of significant proteinuria, significant albuminuria, and decreased GFR was 88.30%, 41.49% and 31.91% respectively. Participants with significant albuminuria had fewer previous surgeries (p = 0.05), a longer waiting time for surgery (p = 0.02), enalapril usage (p = 0.04), pulmonary hypertension (p = 0.03), higher Hct z-score (p = 0.03) and lower platelet count (p = 0.001) compared with those without significant albuminuria. Using multivariate logistic regression analysis, waiting duration for surgery (p = 0.04), Hct >40% (p = 0.02), and platelet count <290,000/mm³ (p = 0.04) were predictive of microalbuminuria.

CONCLUSIONS

Cyanotic nephropathy can be detected in the first decade of life with the presentation of microalbuminuria. High Hct level and low platelet count were identified as a predictor of microalbuminuria, whereas early cardiac surgery decreased the risk of developing significant albuminuria.

Nephrotic Syndrome in a Child Suffering from Tetralogy of Fallot: A Rare Association

Nephrotic syndrome is an uncommon complication of tetralogy of Fallot and has been rarely reported in pediatric population. We describe a 4-year-old female Congolese child who was referred for investigation for persistent dyspnea, edema, and cyanosis and nephrotic range proteinuria. Our patient presented with a tetralogy of Fallot and nephrotic syndrome. Conclusion. This case reminds us that children with tetralogy of Fallot may develop nephrotic proteinuria.

Successful initiation and maintenance of hemodialysis in an adult patient with complete transposition of the great arteries

Cyanotic congenital heart disease (CCHD) is a life-threatening cardiac defect that requires palliative or corrective surgery in early life. Major advances in medical and surgical management have resulted in the survival of CCHD patients to adulthood with or without corrective surgery, though some are at risk of development of end-stage renal disease (ESRD) due to cyanotic nephropathy (CN). There is little or no information on the initiation and maintenance of hemodialysis (HD) in such patients. We present here a case of a 44-year-old man with complete transposition of the great arteries and CN-related ESRD. He had only received a bi-directional Glenn's operation and still suffered persistent severe hypoxemia and impaired cardiac function. ESRD was successfully treated with HD over more than 4 years. The case emphasizes the need for special attention in the selection and initiation of renal replacement therapy.

Chronic cyanosis and vascular function: implications for patients with cyanotic congenital heart disease

In patients with cyanotic congenital heart disease, chronic hypoxaemia leads to important changes in blood vessel function and structure. Some of these alterations are maladaptive and probably contribute to impaired cardiopulmonary performance and an increased incidence of thrombotic and embolic events. Recent evidence suggests that deranged endothelial function, a sequel of chronic cyanosis, could be an important factor in the pathogenesis of cyanosis-associated cardiovascular risk. In this article, we discuss the physiological and mechanical consequences of compensatory erythrocytosis and possible pathophysiological mechanisms of vascular dysfunction in chronic cyanosis.

Repeated phlebotomies improve and stabilise renal function in cyanotic nephropathy

Patients over 10 years of age with cyanotic congenital heart disease (CCHD) risk developing significant glomerular proteinuria, a condition called cyanotic nephropathy. Even though the pathogenesis of glomerulopathy associated with CCHD is still unclear, a potential mechanism is hyperviscosity-induced decrease in peritubular capillary blood flow leading to an increase in glomerular capillary pressure, in turn resulting in proteinuria. Although angiotensin-converting enzyme (ACE) inhibitors have been traditionally used in the treatment of these patients with cyanotic nephropathy, they may, however, not be well tolerated. Here we present a case of an adult patient with CCHD who could not tolerate an ACE inhibitor but showed improvement and stabilisation of her renal function following treatment with repeated phlebotomies.