Pheochromocytoma in Congenital Cyanotic Heart Disease

Risk of malignancy in adult patients with congenital heart disease: a clinical practice review

This paper presents case studies of adult patients with congenital heart disease (CHD) who developed cancer and also discusses relevant epidemiological studies, risk factors, and reports on early detection. Herein, we describe three cases: a 63-year-old man with an atrial septal defect and multiple myeloma; a 48-year-old man with tetralogy of Fallot and colorectal cancer; and a 25-year-old man with Fontan circulation and hepatocellular carcinoma (HCC). Previous studies have found that the incidence of cancer in adult patients with CHD is higher than that in the general population. The management of adult patients with CHD complicated by cancer requires careful attention because cancer treatment alone can affect the survival prognosis and quality of life, as well as the pathophysiology and treatment of underlying heart disease. Apart from known risk factors in the non-CHD population, specific risk factors have been reported, such as genetic abnormalities, low-dose ionizing radiation exposure, early thymectomy, Fontan-associated liver disease, and hypoxia. Encouraging patients to participate in cancer screening and avoid known risk factors is essential in daily practice for the early diagnosis and prevention of cancer. It is also important to be vigilant for initial signs that are indicative of cancer as well as avoidable risk factors.

Paraganglioma and phaeochromocytoma in adult Fontan patients

INTRODUCTION

The purpose of this study was to address the gap in knowledge in the incidence, presentation and imaging features of PPGL in Fontan patients. It has been hypothesised in the literature that Fontan circulation patients have an increased incidence of these tumours. This study is the largest cohort of adult Fontan patients in North America. The Fontan procedure is a palliative procedure for single ventricle congenital heart disease where the systemic venous return is directed into the pulmonary circulation. Fontan patients are at increased risk of developing several extracardiac complications including phaeochromocytoma and paraganglioma (PPGL).

METHODS

This retrospective single-centre study includes all adult patients who were treated between 1 September 2015 and 1 September 2022 in a tertiary referral centre for adult congenital heart disease. Imaging and electronic medical records were retrospectively searched for the presence of PPGL.

RESULTS

Five hundred and forty-seven Fontan patients were included in the study. Three patients had PPGL with an incidence of 0.5%. Two patients were diagnosed with paraganglioma and one with phaeochromocytoma. All patients were female. Median age of Fontan procedure was 1.8 years (range: 1.75-27 years). Median age of PPGL diagnosis was 19 years (range: 12-39 years). Median time from Fontan operation to diagnosis of PPGL was 12 years (range: 10.3-17.2 years).

CONCLUSION

Fontan patients are at increased risk of PPGL. Clinically, the diagnosis of PPGL is challenging as symptoms and serum markers can be confounding in this population; however, the imaging features of PPGL remain typical making the role of the radiologist crucial.

Fontan Circulation Associated Organ Abnormalities Beyond the Heart, Lungs, Liver, and Gut: A Systematic Review

Introduction

Patients with a Fontan circulation are at risk for sequelae of Fontan physiology during follow-up. Fontan physiology affects all organ systems and an overview of end-organ damage is needed.

Methods

We performed a systematic review of abnormalities in multiple organ systems for patients with a longstanding Fontan circulation. We searched online databases for articles describing abnormalities in multiple organ systems. Cardio-pulmonary abnormalities, protein losing enteropathy, and Fontan associated liver disease have already extensively been described and were excluded from this systematic review.

Results

Our search returned 5,704 unique articles. After screening, we found 111 articles relating to multiple organ systems. We found abnormalities in, among others, the nervous system, pituitary, kidneys, and musculoskeletal system. Pituitary edema—relating to the unique pituitary vasculature- may affect the thyroid axis. Renal dysfunction is common. Creatinine based renal function estimates may be inappropriate due to myopenia. Both lean muscle mass and bone mineral density are decreased. These abnormalities in multiple organ systems may be related to Fontan physiology, cyanosis, iatrogenic factors, or lifestyle.

Conclusions

Health care providers should be vigilant for hypothyroidism, visual or hearing deficits, and sleep disordered breathing in Fontan patients. We recommend including cystatin C for assessment of renal function. This review may aid health care providers and guide future research.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232461, PROSPERO, identifier: CRD42021232461.

MicroRNA-486-5p down-regulation protects cardiomyocytes against hypoxia-induced cell injury by targeting IGF-1

BACKGROUND

MicroRNA has been reported to play an important role in congenital heart disease (CHD) in children. Recently, microRNA-486-5p (miR-486-5p) has been found increased in patients with cyanotic heart disease compared with those without heart disease. The present study aimed to investigate the effect of miR-486-5p on hypoxia-induced cardiomyocyte injury to reveal the role of miR-486-5p in cyanotic congenital heart disease (CCHD).

METHODS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to determine the expression of miR-486-5p in hypoxia-induced H9C2 cells. Dual luciferase reporter gene assay was used to confirm IGF-1 was a direct target of miR-486-5p. miR-486-5p inhibitor and IGF-1-siRNA were transfected into H9C2 cells. The cell viability was detected by MTT. Cell apoptosis was detected using flow cytometry. The expression of IGF-1, Bcl-2, caspase-3, caspase-9, and Bax mRNA and protein were detected by RT-qPCR and western blotting, respectively.

RESULTS

miR-486-5p expression gradually increased with prolonged hypoxia time in H9C2 cells. Dual luciferase reporter gene results confirmed IGF-1 was a direct target of miR-486-5p. In addition, inhibition of miR-486-5p significantly increased the hypoxia-induced decrease in cell survival and attenuated hypoxia-induced apoptosis. Furthermore, inhibition of miR-486-5p significantly attenuated the hypoxia-induced decrease in the level of IGF-1 and Bcl-2 and the increase in pro-apoptotic proteins such as caspase-3, caspase-9 and Bax. These effects could be reversed by IGF-1-siRNA.

CONCLUSION

The data demonstrated that inhibition of miR-486-5p increased cardiomyocyte growth and reduced cell apoptosis under hypoxic conditions by targeting IGF-1, indicating that miR-486-5p may be an effective target for the treatment of CCHD.