Congenital Heart Disease in the Older Adult

The renin-angiotensin-aldosterone-system and right heart failure in congenital heart disease

Adults with congenital heart disease represent a rapidly growing patient group. Dysfunction of the right ventricle is often present, and right heart failure constitutes the main cause of death. Heart failure therapies used in acquired left heart failure are often initiated in adults with right heart failure due to congenital heart disease, but the right ventricle differs substantially from the left ventricle, and the clinical evidence for this treatment strategy is lacking.

In this review, we identified existing clinical studies evaluating the effects of ACE inhibitors, angiotensin II receptor blockers and aldosterone antagonists in adults with congenital heart disease by a systematic literature search. From 13 identified studies no clear evidence of beneficial effects was found, but the design of the studies limits the validity of the results. The studies in general include low numbers of patients, have short follow-up periods and evaluate surrogate endpoints instead of hard clinical endpoints. Specific evaluation of symptomatic patients with a systemic right ventricle indicates that these patients may benefit from RAAS inhibitory treatments, but this requires further investigation.

To conclude, existing studies do not support the use of RAAS inhibitory treatments in right heart failure due to congenital heart disease but contain important limitations. Hence, there is a need for new well-designed trials including higher numbers of patients and validated endpoints to optimize and guide future treatment of this patient group.

[Competence Network for Congenital Heart Defects: innovative research for a young patient group]

BACKGROUND

Congenital heart disease is the most frequent congenital malformation in humans and affects almost 1 % of all newborns. Thanks to advances in diagnostics and treatment, over 90 % of those affected reach adulthood today. Patient numbers are therefore growing constantly. The majority of those affected, however, remain chronically ill throughout life and require continuous specialized care. The spectrum of different clinical pictures is vast. Since this is a relatively young patient group, both research and care are lacking relevant knowledge and experience.

OBJECTIVE

The Competence Network for Congenital Heart Defects (CNCHD) was founded in 2003 to tackle the challenge of heterogeneity and accordingly small sample sizes by means of networked research. The following article offers an overview of the network and its mode of operation.

MATERIAL AND METHODS

The Germany-wide research network involves all relevant levels of research, public health care, the patient community and the general public. On the basis of a complex and flexible database infrastructure, it facilitates multicenter and interdisciplinary research in the field of congenital heart disease.

RESULTS AND DISCUSSION

The CNCHD succeeded in establishing research on congenital heart disease throughout Germany by providing a powerful research network and a suitable infrastructure. Scientists from across Germany and all over the world use this basis to jointly find answers to burning questions in the field of congenital heart disease.

Evaluation of Adults With Congenital Heart Disease

The clinical approach to adults with congenital heart diseases (ACHDs) is unique in cardiovascular medicine because these patients encompass a broad range of presentations. Each patient, despite having similar diagnosis, will be anatomically and physiologically unlike others within ACHD population, in relation to the type of repair, age at repair, associated defects, with specific long-term risk factors and complications. Furthermore, as many patients will not complain of symptoms, clinical evaluation and diagnostic testing must also be based on the underlying main diagnostic category, with complete standardized lesion-specific clinical protocols, investigating all known risk factors specific for each congenital heart disease and performed as part of screening for significant long-term complications. The first part of this review will focus on clinical history, physical examination, and the most important diagnostic testing in ACHD population. The second part of the article will focus on some clinical issues we have to face in our daily practice, such as heart failure, cyanosis, and pulmonary hypertension. Furthermore, as survival rates of ACHD population continue to improve and patients with this condition live longer, we will briefly report on a new clinical concern regarding the impact of acquired morbidities like coronary artery disease that appear to be of greater importance in defining outcome in older patients with ACHD.

Neurodevelopmental Outcomes of the Child with Congenital Heart Disease

Survival after bypass surgery in moderate and severe congenital heart disease (CHD) has increased dramatically. Although cardiac outcome is often very good, these children are at increased risk of developmental impairments in all developmental domains. Risk factors for developmental impairment include a genetic disorder, preterm birth, longer intensive care stay, poorer socioeconomic environment, and more complex forms of CHD. Health care providers, patients, and parents must be aware and informed about noncardiac sequelae and tertiary centers performing open-heart surgery in neonates and infants must establish a neurodevelopmental follow-up program to provide regular neurodevelopmental assessments. These allow for individual counseling and early detection and treatment of developmental problems.

Genetics of Congenital Heart Defects: The NKX2-5 Gene, a Key Player

Congenital heart defects (CHDs) represent the biggest fraction of morbid congenital anomalies worldwide. Owing to their complex inheritance patterns and multifactorial etiologies, these defects are difficult to identify before complete manifestation. Research over the past two decades has established firmly the role of genetics in the development of these congenital defects. While syndromic CHDs are more straightforward, non-syndromic CHDs are usually characterized by multiple mutations that affect intricate inter-connected developmental pathways. Knock-out and gene expression studies in mice and other genetic models have been performed to elucidate the roles of these implicated genes. Functional analysis has not been able to resolve the complete picture, as increasingly more downstream effects are continuously being assigned to CHD mutant factors. NKX2-5, a cardiac transcription factor, has received much attention for its role in cardiac dysmorphogenesis. Approximately 50 different mutations in this gene have been identified to date, and only a few have been functionally characterized. The mutant NKX2-5 factor can regulate a number of off-targets downstream to facilitate CHD development. This review summarizes the genetic etiology of congenital heart defects and emphasizes the need for NKX2-5 mutation screening.

The pediatric heart network: meeting the challenges to multicenter studies in pediatric heart disease

PURPOSE OF REVIEW

Because of the relatively small numbers of pediatric patients with congenital heart disease cared for in any individual center, there is a significant need for multicenter clinical studies to validate new medical or surgical therapies. The Pediatric Heart Network (PHN), with 15 years of experience in multicenter clinical research, has tackled numerous challenges when conducting multicenter studies.

RECENT FINDINGS

This review describes the challenges encountered and the strategies employed to conduct high-quality, collaborative research in pediatric cardiovascular disease.

SUMMARY

Sharing lessons learned from the PHN can provide guidance to investigators interested in conducting pediatric multicenter studies.

Increased Body Mass Index Is Associated with Congestive Heart Failure and Mortality in Adult Fontan Patients

OBJECTIVE

Obesity affects adults with congenital heart disease (CHD). The effect of an increased body mass index (BMI) with respect to morbidity and mortality has not been evaluated in adults with complex CHD. Our objective was to evaluate the effects of increased BMI on heart failure and mortality in univentricular patients who had undergone Fontan palliation.

METHODS

A query of Fontan patients' first appointments at the Washington University Center for Adults with CHD between 2007 and 2014 yielded 79 patients. BMI status as normal (<25 kg/m(2) ), overweight (≥25, <30 kg/m(2) ), and obese (≥30 kg/m(2) ) was established at the patient's first appointment. We analyzed demographics, diuretic requirements, New York Heart Association (NYHA) class, and laboratory values using Student's two-sample t-test and Fisher's exact test. Mortality was assessed via survival curves, and hazard ratios were compiled with proportional hazard modeling.

RESULTS

The recent average BMI was significantly greater in patients with NYHA classes II-IV (29.3 ± 9 kg/m(2) ) compared with asymptomatic patients (24.8 ± 5.1 kg/m(2) , P = .006). Additionally, the average BMI of patients with a high diuretic requirement (≥40 mg/day IV furosemide equivalent) was obese, at 32.15 ± 9.1 kg/m(2) , compared with 25.91 ± 7.3 kg/m(2) for those on no or lower doses of diuretics (P = .009). Eighteen of the 79 patients met an endpoint of death, hospice placement, or cardiac transplant by the study conclusion. Kaplan-Meier analysis from time of first appointment until recent follow-up revealed a significant association between time to combined endpoint and BMI class. Cox proportional hazard modeling with age adjustment yielded a hazard ratio of 3.2 (95% CI 1.096-9.379) for obesity upon first presentation to an adult CHD clinic.

CONCLUSIONS

In patients with univentricular hearts and Fontan palliation, obesity is associated with symptomatic heart failure and mortality.