Stem Cell and Exosome Therapy in Pulmonary Hypertension

Pulmonary hypertension is a rare and progressive illness with a devastating prognosis. Promising research efforts have advanced the understanding and recognition of the pathobiology of pulmonary hypertension. Despite remarkable achievements in terms of improving the survival rate, reducing disease progression, and enhancing quality of life, pulmonary arterial hypertension (PAH) is not completely curable. Therefore, an effective treatment strategy is still needed. Recently, many studies of the underlying molecular mechanisms and technological developments have led to new approaches and paradigms for PAH treatment. Management based on stem cells and related paracrine effects, epigenetic drugs and gene therapies has yielded prospective results for PAH treatment in preclinical research. Further trials are ongoing to optimize these important insights into clinical circumstances.

Long-term Outcome of Fontan-Associated Protein-Losing Enteropathy: Treatment Modality and Predictive Factor of Mortality

Background and Objectives@#Protein-losing enteropathy (PLE) is a devastating complication after the Fontan operation. This study aimed to investigate the clinical characteristics, treatment response, and outcomes of Fontan-associated PLE. @*Methods@#We reviewed the medical records of 38 patients with Fontan-associated PLE from 1992 to 2018 in 2 institutions in Korea. @*Results@#PLE occurred in 4.6% of the total 832 patients after the Fontan operation. After a mean period of 7.7 years after Fontan operation, PLE was diagnosed at a mean age of 11.6years. The mean follow-up period was 8.9 years. The survival rates were 81.6% at 5 years and 76.5% at 10 years. In the multivariate analysis, New York Heart Association Functional classification III or IV (p=0.002), low aortic oxygen saturation (<90%) (p=0.003), and ventricular dysfunction (p=0.032) at the time of PLE diagnosis were found as predictors of mortality. PLE was resolved in 10 of the 38 patients after treatment. Among medical managements, an initial heparin response was associated with survival (p=0.043). Heparin treatment resulted in resolution in 4 patients. We found no evidence on pulmonary vasodilator therapy alone. PLE was also resolved after surgical Fontan fenestration (2/6), aortopulmonary collateral ligation (1/1), and transplantation (1/1). @*Conclusions@#The survival rate of patients with Fontan-associated PLE has improved with the advancement of conservative care. Although there is no definitive method, some treatments led to the resolution of PLE in one-fourth of the patients. Further investigations are needed to develop the best prevention and therapeutic strategies for PLE.

Valsartan Dosage on Ventriculo-Vascular Coupling Index Dose-Dependency in Heart Failure Patients

Purpose@#Heart failure (HF) poses significant morbidity and mortality. Recently, the ventriculo-vascular coupling index (VVI) was introduced as an independent prognostic factor reflective of the overall cardiovascular performance index in HF. We aimed to determine the effectiveness of force-titration of valsartan on VVI values in HF patients. @*Materials and Methods@#In this multicenter and prospective observational trial, the effect of valsartan was stratified according to dosages [non-ceiling dose (NCD) vs. ceiling dose (CD)] in HF patients with left ventricular ejection fraction (LVEF) <55%. Biochemical studies, including N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiography with VVI, the treadmill test, and the activity scale index were assessed at baseline and after 24 weeks of treatment. @*Results@#One-hundred thirty-eight patients were force-titrated to either a CD group (n=81) or a NCD group (n=57). The mean age of the study participants was 59 years and 66% were male. After 6 months of follow up, left ventricular mass index (LVMI) values had significantly improved in the CD group but not in the NCD group. Intriguingly, in HF patients with a reduced ejection fraction (HFrEF) (n=52, LVEF <40%), a significant improvement in VVI was only observed in the CD group (from 2.4±0.6 to 1.8±0.5, p<0.001). @*Conclusion@#CDs of valsartan for 6 months showed better improvement in VVI, as well as LVMI, in patients with HFrEF, compared with NCDs.

Valsartan Dosage on Ventriculo-Vascular Coupling Index Dose-Dependency in Heart Failure Patients

Purpose@#Heart failure (HF) poses significant morbidity and mortality. Recently, the ventriculo-vascular coupling index (VVI) was introduced as an independent prognostic factor reflective of the overall cardiovascular performance index in HF. We aimed to determine the effectiveness of force-titration of valsartan on VVI values in HF patients. @*Materials and Methods@#In this multicenter and prospective observational trial, the effect of valsartan was stratified according to dosages [non-ceiling dose (NCD) vs. ceiling dose (CD)] in HF patients with left ventricular ejection fraction (LVEF) <55%. Biochemical studies, including N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiography with VVI, the treadmill test, and the activity scale index were assessed at baseline and after 24 weeks of treatment. @*Results@#One-hundred thirty-eight patients were force-titrated to either a CD group (n=81) or a NCD group (n=57). The mean age of the study participants was 59 years and 66% were male. After 6 months of follow up, left ventricular mass index (LVMI) values had significantly improved in the CD group but not in the NCD group. Intriguingly, in HF patients with a reduced ejection fraction (HFrEF) (n=52, LVEF <40%), a significant improvement in VVI was only observed in the CD group (from 2.4±0.6 to 1.8±0.5, p<0.001). @*Conclusion@#CDs of valsartan for 6 months showed better improvement in VVI, as well as LVMI, in patients with HFrEF, compared with NCDs.

Application of Multigene Panel Sequencing in Patients with Prolonged Rate-corrected QT Interval and No Pathogenic Variants Detected in KCNQ1, KCNH2, and SCN5A

Long QT syndrome (LQTS) is an inherited cardiac disease characterized by a prolonged heart rate-corrected QT (QTc) interval. We investigated the genetic causes in patients with prolonged QTc intervals who were negative for pathogenic variants in three major LQTS-related genes (KCNQ1, KCNH2, and SCN5A). Molecular genetic testing was performed using a panel including 13 LQTS-related genes and 67 additional genes implicated in other cardiac diseases. Overall, putative genetic causes of prolonged QTc interval were identified in three of the 30 patients (10%). Among the LQTS-related genes, we detected a previously reported pathogenic variant, CACNA1C c.1552C>T, responsible for cardiac-only Timothy syndrome. Among the genes related to other cardiac diseases, a likely pathogenic variant, RYR2 c.11995A>G, was identified in a patient with catecholaminergic polymorphic ventricular tachycardia. Another patient who developed dilated cardiomyopathy with prolonged QTc interval was found to carry a likely pathogenic variant, TAZ c.718G>A, associated with infantile dilated cardiomyopathy. Comprehensive screening of genetic variants using multigene panel sequencing enables detection of genetic variants with a possible involvement in QTc interval prolongation, thus uncovering unknown molecular mechanisms underlying LQTS.

Idiopathic midaortic syndrome with malignant hypertension in 3-year-old boy / 소아과

Midaortic syndrome (MAS) is a rare vascular disease that commonly causes renovascular hypertension. The lumen of the abdominal aorta narrows and the ostia of the branches show stenosis. MAS is associated with diminished pulses in the lower extremities compared with the upper extremities, severe hypertension with higher blood pressure in the upper rather than lower extremities, and an abdominal bruit. The clinical symptoms are variable, and recognition in children with hypertension can aid early diagnosis and optimal treatment. Hypertension with MAS is malignant and often refractory to several antihypertensive drugs. Recently, radiologic modalities have been developed and have led to numerous interventional procedures. We describe the case of a 3-year-old boy presenting with left ventricular hypertrophy whose severely elevated blood pressure led to the diagnosis of idiopathic MAS. This case highlights the importance of measuring blood pressure and conducting a detailed physical examination to diagnose MAS. This is the first reported case of idiopathic MAS diagnosed in childhood in Korea.

Alagille syndrome and a JAG1 mutation: 41 cases of experience at a single center / 소아과

PURPOSE: Alagille syndrome is a complex hereditary disorder that is associated with cardiac, hepatic, skeletal, ocular, and facial abnormalities. Mutations in the Notch signaling pathway, such as in JAG1 and NOTCH2, play a key role in embryonic development. A cardiac or hepatic presentation is a critical factor for determining the prognosis. METHODS: We conducted a retrospective study of 41 patients with Alagille syndrome or a JAG1 mutation between 1983 and 2013. RESULTS: The first presentations were jaundice, murmur, cyanosis, and small bowel obstruction at a median age of 1.0 months (range, 0-24 months). The JAG1 mutation was found in 27 of the 28 genetically-tested patients. Cardiovascular anomalies were identified in 36 patients, chronic cholestasis was identified in 34, and liver transplantation was performed in 9. There was no significant correlation between the severity of the liver and cardiac diseases. The most common cardiovascular anomaly was peripheral pulmonary stenosis (83.3%), with 13 patients having significant hemodynamic derangement and 12 undergoing surgical repair. A total bilirubin level of >15 mg/dL with a complex surgical procedure increased the surgical mortality (P=0.022). Eight patients died after a median period of 2.67 years (range, 0.33-15 years). The groups with fetal presentation and with combined severe liver and heart disease had the poorest survival (P<0.001). CONCLUSION: The group with combined severe liver and heart disease had the poorest survival, and a multidisciplinary approach is necessary to improve the outcome.

The strong association of left-side heart anomalies with Kabuki syndrome / 소아과

PURPOSE: Kabuki syndrome is a multiple congenital malformation syndrome, with characteristic facial features, mental retardation, and skeletal and congenital heart anomalies. However, the cardiac anomalies are not well described in the Korean population. We analyzed the cardiac anomalies and clinical features of Kabuki syndrome in a single tertiary center. METHODS: A retrospective analysis was conducted for a total of 13 patients with Kabuki syndrome. RESULTS: The median age at diagnosis of was 5.9 years (range, 9 days to 11 years and 8 months). All patients showed the characteristic facial dysmorphisms and congenital anomalies in multiple organs, and the diagnosis was delayed by 5.9 years (range, 9 days to 11 years and 5 months) after the first visit. Noncardiac anomalies were found in 84% of patients, and congenital heart diseases were found in 9 patients (69%). All 9 patients exhibited left-side heart anomalies, including hypoplastic left heart syndrome in 3, coarctation of the aorta in 4, aortic valve stenosis in 1, and mitral valve stenosis in 1. None had right-side heart disease or isolated septal defects. Genetic testing in 10 patients revealed 9 novel MLL2 mutations. All 11 patients who were available for follow-up exhibited developmental delays during the median 4 years (range, 9 days to 11 years 11 months) of follow-up. The leading cause of death was hypoplastic left heart syndrome. CONCLUSION: Pediatric cardiologist should recognize Kabuki syndrome and the high prevalence of left heart anomalies with Kabuki syndrome. Genetic testing can be helpful for early diagnosis and counseling.

Idiopathic Constriction of the Fetal Ductus Arteriosus with Right Ventricular Failure; Rapid Resolution after Birth / 대한주산의학회잡지

Premature constriction of the ductus arteriosus is rare, but it can occur during fetal life idiopathically or secondary to medications or structural lesions. Premature constriction of the ductus arteriosus can lead to progressive right heart dysfunction, heart failure, subsequent hydrops fetalis, and even fetal death. Herein, we describe a case of fetal ductus arteriosus constriction of unknown etiology with a severely enlarged and hypertrophied right ventricle, which resolved dramatically soon after birth.