The Waiting List Mortality of Pediatric Heart Transplantation Candidates in Korea before the Pediatric Ventricular Assist Device Era

Background@#Despite advancements in heart transplantation for pediatric patients in Korea, the waiting list mortality has not been reported. Therefore, we investigated the waiting list mortality rate and factors associated with patient mortality. @*Methods@#We reviewed the medical records of pediatric patients who were registered for heart transplantation at three major hospitals in Korea from January 2000 to January 2020.All patients who died while waiting for heart transplantation were investigated, and we identified the waiting list mortality rate, causes of mortality and the median survival periods depending on the variable risk factors. @*Results@#A total of 145 patients received heart transplantations at the three institutions we surveyed, and the waiting list mortality rate was 26%. The most common underlying diseases were cardiomyopathy (66.7%) and congenital heart disease (30.3%). The leading causes that contributed to death were heart failure (36.3%), multi-organ failure (27.2%), and complications associated with extracorporeal membrane oxygenation (ECMO) (25.7%). The median survival period was 63 days. ECMO was applied in 30 patients. The different waiting list mortality percentages according to age, cardiac diagnosis, use of ECMO, and initial Korean Network of Organ Sharing (KONOS) level were determined using univariate analysis, but age was the only significant factor associated with waiting list mortality based on a multivariate analysis. @*Conclusion@#The waiting list mortality of pediatric heart transplantation candidates was confirmed to be considerably high, and age, underlying disease, the application of ECMO, and the initial KONOS level were the factors that influenced the survival period.

Identification of rare coding variants associated with Kawasaki disease by whole exome sequencing

Kawasaki disease (KD) is an acute pediatric vasculitis that affects genetically susceptible infants and children. To identify coding variants that influence susceptibility to KD, we conducted whole exome sequencing of 159 patients with KD and 902 controls, and performed a replication study in an independent 586 cases and 732 controls. We identified five rare coding variants in five genes (FCRLA, PTGER4, IL17F, CARD11, and SIGLEC10) associated with KD (odds ratio [OR], 1.18–4.41; p = 0.0027–0.031). We also performed association analysis in 26 KD patients with coronary artery aneurysms (CAAs; diameter > 5 mm) and 124 patients without CAAs (diameter < 3 mm), and identified another five rare coding variants in five genes (FGFR4, IL31RA, FNDC1, MMP8, and FOXN1), which may be associated with CAA (OR, 3.89–37.3; p = 0.0058–0.0261). These results provide insights into new candidate genes and genetic variants potentially involved in the development of KD and CAA.

Growth Pattern of the Neo-Aorta after Arterial Switch Operation during Childhood

Background and Objectives@#Neo-aortic root dilatation (ARD) and annular dilatation (AAD) tend to develop after arterial switch operation (ASO). However, the trend of neo-aortic growth has not been well established. This paper aims to identify this trend, its associated factors, and predictors of neo-aortic dilatation after ASO. @*Methods@#We analyzed the growth trend of the neo-aortic root, annulus, and sinotubular junction (STJ) z-scores using random coefficients model and the risk factors affecting neoaortic dilatation in 163 patients who underwent ASO from 2006 to 2015. @*Results@#Among 163 patients, 41 had a ventricular septal defect, and 11 had Taussig-Bing (TB) anomaly. The median follow-up duration was 6.61 years. The increased in the neo-aortic root z-score was different between the trapdoor and non-trapdoor coronary artery transfer techniques (0.149/year, p<0.001 vs. 0.311/year, p<0.001). Moreover, the neo-aortic annulus and STJ z-score significantly increased over time after ASO (0.067/year, p<0.001; 0.309/ year, p<0.001). Pulmonary artery banding (PAB) was rather a negative affecting factor. The probabilities of freedom from ARD, AAD, and neo-aortic STJ dilatation at 10 years after ASO were 33.4%, 53.9%, and 65.4%. Neo- aortic regurgitation within 1 year was the predictor of ARD, AAD, and neo-aortic STJ dilatation. TB anomaly, PAB, and native pulmonary sinus z-score were other predictors for ARD. @*Conclusion@#The growth of neo-aortic root, annulus, and STJ after ASO was greater than somatic growth during childhood. The coronary artery transfer technique affected the growth pattern of the neo-aortic root.

Growth Pattern of the Neo-Aorta after Arterial Switch Operation during Childhood

Background and Objectives@#Neo-aortic root dilatation (ARD) and annular dilatation (AAD) tend to develop after arterial switch operation (ASO). However, the trend of neo-aortic growth has not been well established. This paper aims to identify this trend, its associated factors, and predictors of neo-aortic dilatation after ASO. @*Methods@#We analyzed the growth trend of the neo-aortic root, annulus, and sinotubular junction (STJ) z-scores using random coefficients model and the risk factors affecting neoaortic dilatation in 163 patients who underwent ASO from 2006 to 2015. @*Results@#Among 163 patients, 41 had a ventricular septal defect, and 11 had Taussig-Bing (TB) anomaly. The median follow-up duration was 6.61 years. The increased in the neo-aortic root z-score was different between the trapdoor and non-trapdoor coronary artery transfer techniques (0.149/year, p<0.001 vs. 0.311/year, p<0.001). Moreover, the neo-aortic annulus and STJ z-score significantly increased over time after ASO (0.067/year, p<0.001; 0.309/ year, p<0.001). Pulmonary artery banding (PAB) was rather a negative affecting factor. The probabilities of freedom from ARD, AAD, and neo-aortic STJ dilatation at 10 years after ASO were 33.4%, 53.9%, and 65.4%. Neo- aortic regurgitation within 1 year was the predictor of ARD, AAD, and neo-aortic STJ dilatation. TB anomaly, PAB, and native pulmonary sinus z-score were other predictors for ARD. @*Conclusion@#The growth of neo-aortic root, annulus, and STJ after ASO was greater than somatic growth during childhood. The coronary artery transfer technique affected the growth pattern of the neo-aortic root.

Assessment of the Clinical Heterogeneity of Kawasaki Disease Using Genetic Variants of BLK and FCGR2A

BACKGROUND AND OBJECTIVES@#Patients with Kawasaki disease (KD) are clinically heterogeneous because its diagnosis is based solely on clinical observation and there are no definitive biomarkers. We dissected the clinical heterogeneity of KD patients using the KD-associated genetic variants.@*METHODS@#We performed a genetic association analysis in several KD subgroups categorized by clinical characteristics using the KD-associated variants of the B lymphoid tyrosine kinase (BLK; rs6993775) and Fc gamma receptor II a (FCGR2A; rs1801274) in a large number of case (n=1,011) and control (n=4,533) samples.@*RESULTS@#BLK and FCGR2A were very significantly associated with KD in Korean KD patients (odds ratio [OR],1.48; p=4.63×10⁻¹¹ for BLK, and OR, 1.26; p=1.42×10⁻⁴ for FCGR2A). However, in KD subgroup analysis, we found that neither BLK nor FCGR2A were associated with either incomplete Kawasaki disease (iKD) type patients or those older than 5 years of age (p>0.2), suggesting that patients with iKD or those older than 5 years of age are a unique subgroup of KD. In genetic association analysis after excluding iKD patients and those older than 5 years old, we found that BLK was associated with all KD subgroups, whereas FCGR2A was specifically associated with male KD patients younger than 1 year of age (OR, 2.22; p=2.35×10⁻⁵).@*CONCLUSIONS@#KD is a clinically and genetically heterogeneous disease. These findings will provide new insights into the clinical and genetic heterogeneity of KD.

Assessment of the Clinical Heterogeneity of Kawasaki Disease Using Genetic Variants of BLK and FCGR2A

BACKGROUND AND OBJECTIVES: Patients with Kawasaki disease (KD) are clinically heterogeneous because its diagnosis is based solely on clinical observation and there are no definitive biomarkers. We dissected the clinical heterogeneity of KD patients using the KD-associated genetic variants. METHODS: We performed a genetic association analysis in several KD subgroups categorized by clinical characteristics using the KD-associated variants of the B lymphoid tyrosine kinase (BLK; rs6993775) and Fc gamma receptor II a (FCGR2A; rs1801274) in a large number of case (n=1,011) and control (n=4,533) samples. RESULTS: BLK and FCGR2A were very significantly associated with KD in Korean KD patients (odds ratio [OR],1.48; p=4.63×10⁻¹¹ for BLK, and OR, 1.26; p=1.42×10⁻⁴ for FCGR2A). However, in KD subgroup analysis, we found that neither BLK nor FCGR2A were associated with either incomplete Kawasaki disease (iKD) type patients or those older than 5 years of age (p>0.2), suggesting that patients with iKD or those older than 5 years of age are a unique subgroup of KD. In genetic association analysis after excluding iKD patients and those older than 5 years old, we found that BLK was associated with all KD subgroups, whereas FCGR2A was specifically associated with male KD patients younger than 1 year of age (OR, 2.22; p=2.35×10⁻⁵). CONCLUSIONS: KD is a clinically and genetically heterogeneous disease. These findings will provide new insights into the clinical and genetic heterogeneity of KD.

Clinical Significance of the Bacille Calmette-Guérin Site Reaction in Kawasaki Disease Patients Aged Less than 18 Months

PURPOSE: The purpose of this study was to investigate the clinical significance of Bacille Calmette-Guérin (BCG) site reaction in terms of diagnosis and outcome prediction in young children with Kawasaki disease (KD). METHODS: The incidence of BCG site reaction in the respective age ranges was investigated in 1,058 patients who were admitted at Asan Medical Center between January 2006 and February 2017. The 416 patients under 18 months of age were enrolled as subjects for the analysis of the association between BCG site reaction and other laboratory and clinical findings. The analysis was performed separately in complete and incomplete KD groups. RESULTS: The incidence rate of BCG site reaction was peaked at 6–12 months (83%) and decreased with increasing age after 12 months in 1,058 patients (P < 0.001). The incidence rate was above 70% in KD aged less than 18 months and more frequent than those of cervical lymphadenopathy. The logistic regression analyses showed that the principal clinical findings including conjunctivitis (P=0.781), red lips/oral mucosa (P=0.963), rash (P=0.510), cervical lymphadenopathy (P=0.363), changes in extremities (P=0.283) and the coronary artery aneurysm (P=0.776) were not associated with the BCG site reaction. CONCLUSIONS: The BCG site reaction could be a useful diagnostic tool independent to principal clinical findings in KD developing in children aged < 18 months, who underwent BCG vaccination. Outcome of KD patients was not different between groups with or without the BCG site reaction in both complete KD and incomplete KD.

Identification of LEF1 as a Susceptibility Locus for Kawasaki Disease in Patients Younger than 6 Months of Age

Kawasaki disease (KD) is an acute febrile vasculitis predominately affecting infants and children. The dominant incidence age of KD is from 6 months to 5 years of age, and the incidence is unusual in those younger than 6 months and older than 5 years of age. We tried to identify genetic variants specifically associated with KD in patients younger than 6 months or older than 5 years of age. We performed an age-stratified genome-wide association study using the Illumina HumanOmni1-Quad BeadChip data (296 cases vs. 1,000 controls) and a replication study (1,360 cases vs. 3,553 controls) in the Korean population. Among 26 candidate single nucleotide polymorphisms (SNPs) tested in replication study, only a rare nonsynonymous SNP (rs4365796: c.1106C>T, p.Thr369Met) in the lymphoid enhancer binding factor 1 (LEF1) gene was very significantly associated with KD in patients younger than 6 months of age (odds ratio [OR], 3.07; p(combined) = 1.10 × 10⁻⁵), whereas no association of the same SNP was observed in any other age group of KD patients. The same SNP (rs4365796) in the LEF1 gene showed the same direction of risk effect in Japanese KD patients younger than 6 months of age, although the effect was not statistically significant (OR, 1.42; p = 0.397). This result indicates that the LEF1 gene may play an important role as a susceptibility gene specifically affecting KD patients younger than 6 months of age.

A comparative study of established z score models for coronary artery diameters in 181 healthy Korean children / 소아과

PURPOSE: The aim of this study was to investigate the statistical properties of four previously developed pediatric coronary artery z score models in healthy Korean children. METHODS: The study subjects were 181 healthy Korean children, whose age ranged from 1 month to 15 years. The diameter of each coronary artery was measured using 2-dimensional echocardiography and converted to the z score in the four models (McCrindle, Olivieri, Dallaire, and Japanese model). Descriptive statistical analyses and 1-sample t tests were performed. RESULTS: All calculated z scores had P values of ≥0.050 using the Kolmogorov-Smirnov test. The one sample t test showed that the mean z scores did not converge to zero except in 1 model, and the mean right coronary artery (RCA) z score was less than zero in all 4 models. The smaller RCA diameter in this study could be associated with the more distal measuring point used to avoid the conal branch. The percentage of subjects with extreme z score values (≥2.0 and ≥2.5) for the left main coronary artery (LMCA) seems to be higher in the Dallaire (4.9% and 3.3%) and Japanese models (7.1% and 3.8%). CONCLUSION: All 4 models showed statistical feasibility of normal distribution. More precise instructions would be needed for the measurement of the RCA. The higher percentage of extreme z scores for the LMCA is compatible with the basic understanding of anatomic variation in the LMCA.

Multicenter, Single-Arm, Phase IV Study of Combined Aspirin and High-Dose “IVIG-SN” Therapy for Pediatric Patients with Kawasaki Disease

BACKGROUND AND OBJECTIVES: Intravenous immunoglobulin-SN (IVIG-SN) is a new human immunoglobulin product. Its safety is ensured by pathogen-elimination steps comprising solvent/detergent treatment and a nanofiltration process. This multicenter clinical study was designed to evaluate the efficacy and safety of combined aspirin and high-dose IVIG-SN therapy in pediatric patients with Kawasaki disease (KD). SUBJECTS AND METHODS: We evaluated coronary artery lesions (CALs) at 2 and 7 weeks after administering IVIG-SN; total fever duration; and variations in erythrocyte sedimentation rate, N-terminal pro B-type natriuretic peptide or B-type natriuretic peptide, and creatine kinase-myocardial band level before and after treatment with IVIG-SN (2 g/kg). Adverse events were monitored. RESULTS: Forty-five patients were enrolled, three of whom were excluded according to the exclusion criteria; the other 42 completed the study. The male:female ratio was 0.91:1, and the mean age was 29.11±17.23 months. The mean fever duration before IVIG-SN treatment was 6.45±1.30 days. Although most patients had complete KD (40 patients, 90.91%), four had atypical KD (9.09%). After IVIG-SN treatment, one patient (2.38%) had CALs, which was significantly lower than the incidence reported previously (15%) (p=0.022), but not significantly different from recent data (5%). There were no serious adverse events, though 28 patients (63.64%) had mild adverse events. Three adverse drug reactions occurred in 2 patients (eczema, anemia, and increased eosinophil count), all of which were transient. CONCLUSION: IVIG-SN treatment in patients with KD was safe and effective.

Prediction of unresponsiveness to second intravenous immunoglobulin treatment in patients with Kawasaki disease refractory to initial treatment / 소아과

PURPOSE: This study investigated predictors of unresponsiveness to second-line intravenous immunoglobulin (IVIG) treatment for Kawasaki disease (KD). METHODS: This was a single-center analysis of the medical records of 588 patients with KD who had been admitted to Asan Medical Center between 2006 and 2014. Related clinical and laboratory data were analyzed by univariate and multivariate logistic regression analyses. RESULTS: Eighty (13.6%) of the 588 patients with KD were unresponsive to the initial IVIG treatment and received a second dose. For these 80 patients, univariate analysis of the laboratory results obtained before administering the second-line IVIG treatment showed that white blood cell count, neutrophil percent, hemoglobin level, platelet count, serum protein level, albumin level, potassium level, and C-reactive protein level were significant predictors. The addition of methyl prednisolone to the second-line regimen was not associated with treatment response (odds ratio [OR], 0.871; 95% confidence interval [CI], 0.216–3.512; P=0.846). Multivariate analysis revealed serum protein level to be the only predictor of unresponsiveness to the second-line treatment (OR, 0.160; 95% CI, 0.028–0.911; P=0.039). Receiver operating characteristic curve analysis to determine predictors of unresponsiveness to the second dose of IVIG showed a sensitivity of 100% and specificity of 72% at a serum protein cutoff level of <7.15 g/dL. CONCLUSION: The serum protein level of the patient prior to the second dose of IVIG is a significant predictor of unresponsiveness. The addition of methyl prednisolone to the second-line regimen produces no treatment benefit.

Diagnostic characteristics of supplemental laboratory criteria for incomplete Kawasaki disease in children with complete Kawasaki disease / 소아과

PURPOSE: In 2004, the American Heart Association (AHA) had published an algorithm for the diagnosis of incomplete Kawasaki disease (KD). The aim of the present study was to investigate characteristics of supplemental laboratory criteria in this algorithm. METHODS: We retrospectively examined the medical records of 355 patients with KD who were treated with intravenous immunoglobulin (IVIG) during the acute phase of the disease. Laboratory data were obtained before the initial IVIG administration and up to 10 days after fever onset. In 106 patients, laboratory testing was performed more than twice. RESULTS: The AHA supplemental laboratory criteria were fulfilled in 90 patients (25.4%), and the frequency of laboratory examination (odds ratio [OR], 1.981; 95% confidence interval [CI], 1.391-2.821; P<0.001) was a significant predictor of it. The fulfillment of AHA supplemental laboratory criteria was significantly associated with refractoriness to the initial IVIG administration (OR, 2.388; 95% CI, 1.182-4.826; P=0.013) and dilatation of coronary arteries (OR, 2.776; 95% CI, 1.519-5.074; P=0.001). CONCLUSION: Repeated laboratory testing increased the rate of fulfillment of the AHA supplemental laboratory criteria in children with KD.

Erratum to: Small Left Atrial Size Complicating Percutaneous Transcatheter Device Closure of Secundum Atrial Septal Defect with Conventional Approach

In this article, on page 218, Fig. 2B and D have errors.

Valve Sparing Aortic Root Replacement in Children with Loeys-Dietz Syndrome

Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder that is characterized by aggressive arterial and aortic disease, often involving the formation of aortic aneurysms. We describe the cases of two children with LDS who were diagnosed with aortic root aneurysms and successfully treated by valve-sparing aortic root replacement (VSRR) with a Valsalva graft. VSRR is a safe and suitable operation for children that avoids prosthetic valve replacement.

Consortium-Based Genetic Studies of Kawasaki Disease in Korea: Korean Kawasaki Disease Genetics Consortium

In order to perform large-scale genetic studies of Kawasaki disease (KD) in Korea, the Korean Kawasaki Disease Genetics Consortium (KKDGC) was formed in 2008 with 10 hospitals. Since the establishment of KKDGC, there has been a collection of clinical data from a total of 1198 patients, and approximately 5 mL of blood samples per patient (for genomic deoxyribonucleic acid and plasma isolation), using a standard clinical data collection form and a nation-wide networking system for blood sample pick-up. In the clinical risk factor analysis using the collected clinical data of 478 KD patients, it was found that incomplete KD type, intravenous immunoglobulin (IVIG) non-responsiveness, and long febrile days are major risk factors for coronary artery lesions development, whereas low serum albumin concentration is an independent risk factor for IVIG non-responsiveness. In addition, we identified a KD susceptibility locus at 1p31, a coronary artery aneurysm locus (KCNN2 gene), and the causal variant in the C-reactive protein (CRP) promoter region, as determining the increased CRP levels in KD patients, by means of genome-wide association studies. Currently, this consortium is continually collecting more clinical data and genomic samples to identify the clinical and genetic risk factors via a single nucleotide polymorphism chip and exome sequencing, as well as collaborating with several international KD genetics teams. The consortium-based approach for genetic studies of KD in Korea will be a very effective way to understand the unknown etiology and causal mechanism of KD, which may be affected by multiple genes and environmental factors.

Small Left Atrial Size Complicating Percutaneous Transcatheter Device Closure of Secundum Atrial Septal Defect with Conventional Approach

BACKGROUND AND OBJECTIVES: Transcatheter device closure becomes the first option for treating secundum atrial septal defect (ASD), but the conventional method is sometimes unsuccessful even when the defect size indicates the closure to be feasible. To increase the success rate, modified methods have been introduced and used. This study aimed to find predictors for using the modified methods in the device closure of secundum ASDs. SUBJECTS AND METHODS: Between October 2010 and December 2012, 92 patients with ASDs underwent the transcatheter device closure. We analyzed the sizes of the defect, the surrounding rims, and the ratios of the left atrium (LA) dimensions to the device size in the patients who underwent the procedure either using the conventional or modified methods. RESULTS: Among the 88 successful cases (95.7%), 22 patients (25%) required modified methods (12 using pulmonary vein and 10 using balloon). The modified method group had the larger size of ASDs and smaller posterosuperior rim. The mean ratios of the LA anteroposterior diameter, width, and length to the device size were all significantly smaller in the modified methods group than in the conventional group (1.20 vs. 1.56, 1.32 vs. 1.71, and 1.61 vs. 2.07, respectively). We found that the risk factors for the modified methods were smaller retroaortic rim, larger ASD, and smaller LA dimension/device size. CONCLUSION: In addition to larger defects and smaller retroaortic rim, the smaller ratios of the LA dimensions to the device size influenced the need for the application of modified methods in the transcatheter device closure of ASDs.

Segmental Analysis of Right Ventricular Longitudinal Deformation in Children before and after Percutaneous Closure of Atrial Septal Defect

BACKGROUND: The aim of study is to identify the dependence of right ventricular (RV) free wall longitudinal deformation on ventricular loading through segmental approach in relatively large number of patients with atrial septal defect (ASD). METHODS: Patients with ASD (n = 114) and age matched healthy children (n = 60) were echocardiographically examined the day before percutaneous device closure and within 24 hours afterwards. RV free wall deformation parameters, strain (small je, Ukrainian) and strain rate (SR), were analyzed in the apical (small je, Ukrainian(A), SR(A)) and basal (small je, Ukrainian(B), SR(B)) segments. Measured deformation parameters were adjusted for RV size (small je, Ukrainian(AL), SR(AL), small je, Ukrainian(BL), SR(BL)) by multiplying by body surface area indexed RV longitudinal dimension. Regression analyses determined the relationships of these deformation parameters with RV loading parameters that were measured by catheterization. RESULTS: small je, Ukrainian(BL) and SR(BL) were not different between pre-closure patients and controls (p = 0.245, p = 0.866), and were decreased post-closure (p = 0.001, p = 0.018). Post-closure small je, Ukrainian(BL) was lower than in controls (p = 0.001). Pre-closure small je, Ukrainian(AL) and SR(AL) were higher than in controls (p = 0.001, p < 0.001), but decreased after closure (all p < 0.001). The pulmonary to systemic flow ratio was related to procedural differences of small je, Ukrainian(BL) (p = 0.017) and of SR(BL) (p = 0.019). RV end diastolic pressure was negatively related to post-closure small je, Ukrainian(BL) (p = 0.020) and post-closure SR(BL) (p = 0.012), and the procedural SR(BL) difference (p = 0.027). CONCLUSION: The longitudinal deformation of the RV basal segment is dependent and its remodeling is also dependent on volume loading in children with ASD.

Diagnosis of incomplete Kawasaki disease / 소아과

Several authors suggested that the clinical characteristics of incomplete presentation of Kawasaki disease are similar to those of complete presentation and that the 2 forms of presentation are not separate entities. Based on this suggestion, a diagnosis of incomplete Kawasaki disease in analogy to the findings of complete presentation is reasonable. Currently, the diagnosis of incomplete Kawasaki disease might be made in cases with fewer classical diagnostic criteria and with several compatible clinical, laboratory or echocardiographic findings on the exclusion of other febrile illness. Definition of incomplete presentation in which coronary artery abnormalities are included as a necessary condition, is restrictive and specific. The validity of the diagnostic criteria of incomplete presentation by the American Heart Association should be thoroughly tested in the immediate future.

Diagnosis of incomplete Kawasaki disease / 소아과

Several authors suggested that the clinical characteristics of incomplete presentation of Kawasaki disease are similar to those of complete presentation and that the 2 forms of presentation are not separate entities. Based on this suggestion, a diagnosis of incomplete Kawasaki disease in analogy to the findings of complete presentation is reasonable. Currently, the diagnosis of incomplete Kawasaki disease might be made in cases with fewer classical diagnostic criteria and with several compatible clinical, laboratory or echocardiographic findings on the exclusion of other febrile illness. Definition of incomplete presentation in which coronary artery abnormalities are included as a necessary condition, is restrictive and specific. The validity of the diagnostic criteria of incomplete presentation by the American Heart Association should be thoroughly tested in the immediate future.

Pulmonary hypertension due to obstructive sleep apnea in a child with Rubinstein-Taybi syndrome / 소아과

Rubinstein-Taybi syndrome (RTS) is characterized by peculiar facies, mental retardation, broad thumbs, and great toes. Approximately one-third of the affected individuals have a variety of congenital heart diseases. They can also have upper airway obstruction during sleep, due to hypotonia and the anatomy of the oropharynx and airway, which make these patients susceptible to obstructive sleep apnea (OSA). In our case, pulmonary hypertension was caused, successively, by congenital heart defects (a large patent ductus arteriosus and arch hypoplasia) and obstructive sleep apnea during early infancy. The congenital heart defects were surgically corrected, but persistent pulmonary hypertension was identified 2 months after the operation. This pulmonary hypertension was due to OSA, and it was relieved by nasal continuous positive airway pressure. This case is the first report of pulmonary hypertension from OSA in a young infant with RTS.