Incidence and risk factors for chronic kidney disease in patients with congenital heart disease

Kidney transplant outcomes in children with simultaneous versus sequential heart-kidney transplants

BACKGROUND

Heart transplant recipients frequently require kidney transplantation for concomitant advanced chronic kidney disease. Data on simultaneous (heart and kidney transplants performed simultaneously) versus sequential (heart transplant performed before kidney) heart-kidney transplants in children are limited. Herein, we compare kidney transplant outcomes between the two groups.

METHOD

We used the Scientific Registry of Transplant Recipients to identify all pediatric (age <21 years) heart transplant recipients who also received a kidney transplant within 10 years of the heart transplant. We divided the study cohort into simultaneous heart-kidney and sequential heart-kidney recipients. We compared patient and death-censored graft survival using the Cox regression, adjusting for age at kidney transplant, sex, race, pre-transplant dialysis, donor type, and prior kidney transplant. We evaluated delayed graft function (defined as dialysis within the first week posttransplant) using logistic regression.

RESULTS

Our analysis cohort included 165 recipients (86 simultaneous and 79 sequential). The incidence of delayed graft function was higher in simultaneous recipients (22.4 vs. 7.7%, p=0.017), but the difference lost statistical significance on multivariable analysis. We found no difference in patient survival (aHR 0.97; 95% CI 0.39, 2.41; p=0.95) after kidney transplant but higher death-censored kidney graft survival in sequential heart-kidney recipients compared with simultaneous heart-kidney recipients (aHR 4.26; 95% CI 1.21, 14.9; p=0.02).

CONCLUSION

Sequential heart-kidney transplants are associated with higher death-censored kidney allograft survival in children compared with simultaneous heart-kidney transplants.

Long-Term Consequences of Acute Kidney Injury After Pediatric Cardiac Surgery: A Systematic Review

OBJECTIVE

The objective of this study was to evaluate the available data on long-term kidney dysfunction, hypertension, and mortality after cardiac surgery-associated acute kidney injury (AKI) in the pediatric population.

STUDY DESIGN

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for eligible studies published from inception through March 2022. Long-term outcomes after pediatric cardiac surgery complicated by AKI and those without were investigated.

RESULTS

We identified 14 studies published between 2013 and 2022 that included a total of 6701 patients (AKI: 1376 patients; no AKI: 5325 patients). These studies used different well-established classifications to define AKI. All the studies suggested that AKI after heart surgery is common in the pediatric patient population and reported a potential link between cardiac surgery-associated AKI and important clinical outcomes. However, only 4 out of 11 studies found a strong association between (absence of recovery from) cardiac surgery-associated AKI and risk of developing chronic kidney disease, and 3 out of 5 studies found a significant increase in mortality rates for pediatric patients who developed AKI after cardiac surgery. Only 1 out of 4 studies found an association between AKI and hypertension at 12 months postoperatively, but found no association at later follow-up times.

CONCLUSIONS

Although there is a trend, evidence on the long-term consequences of cardiac surgery-associated AKI in the pediatric population is mixed. Genetic syndromes, preexisting kidney disease, univentricular or cyanotic heart conditions, and/or high-complexity surgery may be more important for the development of kidney dysfunction by adolescence and early adulthood. Regardless, these children may benefit from a long-term kidney follow-up.

Kidney disease and congenital heart disease: Partnership for life

The literature on the relationship between kidney and cardiovascular diseases is continuously expanding. Scientists have elucidated many of the neurohormonal and hemodynamic pathways involved in cardiorenal disease. However, little is known about kidney disease in patients with congenital heart disease. Given advances in the medical and surgical care of this highly complex patient population, survival rates have dramatically improved leading to a higher percentage of adults living with congenital heart disease. Accordingly, a noticeable increase in the prevalence of kidney disease is appreciated in these patients. Some of the main risk factors for developing chronic kidney disease in the adult congenital heart disease population include chronic hypoxia, neurohormonal derangements, intraglomerular hemodynamic changes, prior cardiac surgeries from minimally invasive to open heart surgeries with ischemia, and nephrotoxins. Unfortunately, data regarding the prevalence, pathophysiology, and prognosis of chronic kidney disease in the adult congenital heart disease population remain scarce. This has led to a lack of clear recommendations for evaluating and managing kidney disease in these patients. In this review, we discuss contemporary data on kidney disease in adults with congenital heart disease in addition to some of the gaps in knowledge we face. The article highlights the delicate interaction between disease of the heart and kidneys in these patients, and offers the practitioner tools to more effectively manage this vulnerable population.

Identification of SOX18 as a New Gene Predisposing to Congenital Heart Disease

Congenital heart disease (CHD) is the most frequent kind of birth deformity in human beings and the leading cause of neonatal mortality worldwide. Although genetic etiologies encompassing aneuploidy, copy number variations, and mutations in over 100 genes have been uncovered to be involved in the pathogenesis of CHD, the genetic components predisposing to CHD in most cases remain unclear. We recruited a family with CHD from the Chinese Han population in the present investigation. Through whole-exome sequencing analysis of selected family members, a new SOX18 variation, namely NM_018419.3:c.349A>T; p.(Lys117*), was identified and confirmed to co-segregate with the CHD phenotype in the entire family by Sanger sequencing analysis. The heterozygous variant was absent from the 384 healthy volunteers enlisted as control individuals. Functional exploration via luciferase reporter analysis in cultivated HeLa cells revealed that Lys117*-mutant SOX18 lost transactivation on its target genes NR2F2 and GATA4, two genes responsible for CHD. Moreover, the genetic variation terminated the synergistic activation between SOX18 and NKX2.5, another gene accountable for CHD. The findings strongly indicate SOX18 as a novel gene contributing to CHD, which helps address challenges in the clinical genetic diagnosis and prenatal prophylaxis of CHD.