Changes in the Incidence of Immune Thrombocytopenia in the Coronavirus Disease 2019 Era: A Nationwide Observational Study in Korea.

Purpose: We investigated whether nonpharmaceutical interventions (NPI) to reduce the spread of coronavirus disease 2019 (COVID-19) was associated with a change in the incidence of immune thrombocytopenia (ITP). Patients and Methods: Using the Korean Health Insurance Review and Assessment Services (HIRA) database, individuals newly diagnosed with ITP between January 2015 and December 2020 were identified. The NPI period was defined as February 2020 to December 2020. The ITP incidence in the NPI period was compared with the mean annual incidence during the same months in the pre-NPI period and the incidence predicted by the autoregressive integrated moving average model. Results: In total, 25,723 patients were identified, and the overall annual incidence of ITP was 8.28 per 100,000 persons ([95% confidence interval (CI): 8.18-8.39]. The ITP incidence in the NPI period was 6.60 per 100,000 person-years (95% CI: 6.37-6.85), 0.77 times (95% CI: 0.74-0.80) lower than that during the pre-NPI period [8.62/100,000 (95% CI: 8.50-8.74)]. With the exception for patients aged ≥70 years, the ITP incidence was significantly lower in the NPI period than in the pre-NPI period. The most significant decline in the ITP incidence during the NPI period was observed in the 0-9 years age group [25.76/100,000 vs 14.01/100,000, P <0.001; incidence rate ratio (IRR): 0.54 (95% CI: 0.51-0.58)]. The intravenous immunoglobulin-treated ITP incidence in the NPI period was 1.69/100,000 (95% CI: 1.58-1.81), 0.79 times (95% CI: 0.73-0.85) lower than that in the pre-NPI period 2.15/100,000 (95% CI: 2.09-2.21)]. The incidence of steroid-treated ITP was lower in the NPI period than in the pre-NPI period (2.73/100,000 vs 2.2/100,000, P <0.001), with an IRR of 0.80 (95% CI: 0.76-0.83). Conclusion: This nationwide study revealed a significant decrease in ITP incidence, particularly among children, after the implementation of NPI.

Effect of a Regional Outbreak of Coronavirus Disease 2019 on Kawasaki Disease in Korea.

Purpose: The association between coronavirus disease 2019 (COVID-19) and Kawasaki disease (KD) remains controversial. Prior to the nationwide epidemic of COVID-19, there was a unique, large-scale, regional outbreak in Daegu and Gyeonsangbuk-do (DG) in Korea in the spring of 2020. We evaluated the impact of COVID-19 on KD by comparing the characteristics of KD incidence between epidemic and non-epidemic regions in Korea. Patients and Methods: We analyzed nationwide Health Insurance Review and Assessment (HIRA) data to estimate KD incidence from February 2019 to July 2020. Patients below 18 years who were admitted with KD and administered both intravenous immunoglobulin and aspirin (ICD-10 code M303 for KD) were included in the study. We compared the incidence of KD in DG and other regions by analyzing the period-specific incidence from February to May before and after the COVID-19 era. Results: A total of 4461 patients were identified to have KD nationwide from February 2019 to July 2020. The nationwide incidence of KD was significantly reduced during this period compared with the period from February 2018 to July 2019 (p < 0.001). In the DG region, within the 0-4-years age group, there was no significant difference in the incidence of KD between periods (p = 0.714). In the 5-9 years age group, a significant decrease in KD incidence was observed in the DG region and all other regions from February 2019 to July 2020. Conclusion: There was a significant decrease in nationwide KD incidence during and until 2 months after the local epidemic in Korea. However, no significant decrease in KD incidence was observed in the 0-4 years age group in the DG region where the local COVID-19 outbreak occurred. A larger study is necessary to determine the correlation between KD in this age group and the COVID-19 outbreak.

Medium- or Higher-Dose Acetylsalicylic Acid for Acute Kawasaki Disease and Patient Outcomes.

OBJECTIVE: To investigate the effect of medium- or higher-dose acetylsalicylic acid (ASA) for treating acute-phase Kawasaki disease to prevent coronary artery aneurysm (CAA). STUDY DESIGN: Among the children with acute Kawasaki disease investigated in the eighth nationwide survey in the Republic of Korea, 8456 children with adequate data were included in this study. The subjects were divided into 2 groups according to the use of medium- or higher-dose ASA (≥30 mg/kg/day), or-low dose ASA (3-5 mg/kg/day) during the acute febrile phase. Both z- score-based criteria and Japanese criteria for CAA were used. RESULTS: The prevalence of CAA based on z-score (24.8% vs 18.3%; P = .001) and on the Japanese criteria (19.0% vs 10.4%; P < .001) was higher in the 7947 patients who received medium- or higher-dose ASA compared with the 509 patients who received low-dose ASA. The use of medium- or higher-dose ASA was a significant predictor of CAA based on both sets of criteria by univariate analysis (based on z-score: OR, 1.472, 95% CI, 1.169-1.854, P = .001; based on Japanese criteria: OR, 2.013, 95% CI, 1.507-2.690, P < .001) and multivariate logistic regression analysis (OR, 1.527, 95% CI, 1.166-2.0, P = .003 and OR, 2.198, 95% CI, 1.563-3.092, P < .001, respectively). CONCLUSIONS: The use of medium- or higher-dose ASA in acute Kawasaki disease did not prevent CAA. A future randomized controlled trial is needed to determine the optimum dose of ASA.

Amiodarone and catheter ablation as cardiac resynchronization therapy for children with dilated cardiomyopathy and wolff-Parkinson-white syndrome.

Preexcitation by accessory pathways (APs) is known to cause dyssynchrony of the ventricle, related to ventricular dysfunction. Correction of ventricular dyssynchrony can improve heart failure in cases of dilated cardiomyopathy (DCMP) with preexcitation. Here, we report the first case of a child with DCMP and Wolff-Parkinson-White (WPW) syndrome treated with amiodarone and radiofrequency catheter ablation (RFCA) in Korea. A 7-year-old boy, who suffered from DCMP and WPW syndrome, showed improved left ventricular function and clinical functional class after treatment with amiodarone to eliminate preexcitation. QRS duration and left ventricular ejection fraction (LVEF) were inversely correlated with amiodarone dosage. After confirming the reduction of preexcitation effects in DCMP, successful RFCA of the right anterior AP resulted in LVEF improvement, along with the disappearance of preexcitation. Our findings suggest that ventricular dyssynchrony, caused by preexcitation in DCMP with WPW syndrome, can worsen ventricular function and amiodarone, as well as RFCA, which should be considered as a treatment option, even in young children.

Clinical characteristics and prognostic factors of primary pulmonary vein stenosis or atresia in children.

BACKGROUND: Primary pulmonary vein stenosis or atresia (PVS/A) is a rare entity with a high mortality rate. The aim of this study was to elucidate the clinical characteristics, progression, and prognostic factors of primary PVS/A in children. METHODS: We reviewed the medical records of patients who had primary PVS/A with normally connected pulmonary veins (PVs) at five pediatric cardiology centers in Korea between 1995 and 2010. RESULTS: A total of 34 cases were identified. The median age at diagnosis was 12.0 months. During the follow-up period (median, 18 months; range, 2 to 185 months), PVS/A progressed to previously uninvolved veins in 9 patients. Surgical interventions were performed on 29 patients (venoplasty on 25 and pneumonectomy on 4). Nineteen of the patients who underwent venoplasty had restenosis after a median of 2 months. The sutureless technique did not reduce the rate of restenosis, progression of the disease to previously uninvolved PVs, or mortality rate. The mortality rate was 46.7%, the median age of death was 10.8 months, and the median interval between diagnosis and death was 3.0 months. In univariate analysis, predictors of death included involvement of at least three PVs, bilateral PV involvement, infancy-onset PVS/A, restenosis after surgery, and progression to previously uninvolved PVs. In multivariate analysis, significant risk factors for death were involvement of at least three PVs (hazard ratio, 8.8; p < 0.0001) and progression to uninvolved PVs (hazard ratio, 4.2; p = 0.014). CONCLUSIONS: Primary PVS/A may carry a significant risk of recurrent and progressive PV obstruction or death even after surgical venoplasty.

Retrospective analysis of the clinical manifestations and survival of Korean patients with mucopolysaccharidosis type II: emphasis on the cardiovascular complication and mortality cases.

Hunter syndrome (mucopolysaccharidosis II, MPS II) is a rare, X-linked disorder of glycosaminoglycan (GAG) catabolism caused by a deficiency in the activity of the lysosomal enzyme, iduronate-2-sulfatase (I2S). In this study, the medical records of 75 Korean patients with Hunter syndrome (74 males, 1 female) were retrospectively reviewed to investigate the frequency of organ involvement and survival at a single center. The three most common symptoms of organ involvement were hepatosplenomegaly (99%), facial dysmorphism (97%), and frequent otitis media (91%). Cardiovascular involvement was also common including valvular abnormalities (89%), left ventricular hypertrophy (68%), and hypertension (30%). The 19 patients who died had a median age of 16.8 years at the time of death. Four of them died within 1 year of the start of enzyme replacement therapy; autopsy showed myocardial infarction with severe coronary artery disease in one patient. Two other patients died due to pneumonia and sleep apnea. In one case, the cause of death was not investigated. The high incidence of hypertension, and the presence of valvular heart disease indicates that close cardiac monitoring is mandatory in all patients with Hunter syndrome, especially relatively older patients even if they are being treated with enzyme replacement therapy.

2009 H1N1 influenza virus infection and necrotizing pneumonia treated with extracorporeal membrane oxygenation.

A 3-year-old girl with acute respiratory distress syndrome due to a H1N1 2009 influenza virus infection was complicated by necrotizing pneumonia was successfully treated with extracorporeal membrane oxygenation (ECMO). This is the first reported case in which a pediatric patient was rescued with ECMO during the H1N1 influenza epidemic in Korea in 2009.

Accuracy of CoaguChek XS for point-of-care antithrombotic monitoring in children with heart disease.

The CoaguChek XS international normalized ratio (INR) assay was compared to INR assay by a standard laboratory method in children with heart disease on anticoagulant therapy. The data comprised 120 pairs of INR values for 42 patients (age <16 yr) who attended a cardiology clinic between 1 May 2007 and 30 January 2008. Parallel INR assays by the CoaguChek XS and the standard method were performed within 1 hr by a single qualified technician and the paired results were evaluated by linear regression and Bland-Altman analysis. The mean difference in the INR values was -0.08 +/- 0.04 units (p = 0.63); the difference between the two results was consistently <0.5 INR units. The slope of the regression line was 0.98 (95% CI: 0.96 to 1.01) and the y-intercept was 0.014 (95% CI: -0.01 to 0.04). In the Bland-Altman analysis, the mean difference in INR between the two methods was 0.08 units and values for 99.4% of the patients fell within the limit of agreement (-0.17 to 0.28 units). In summary, INR assays in children by the CoaguChek XS device are as accurate as the standard method, but faster and more convenient.

A single-center experience with intracardiac thrombosis in children with dilated cardiomyopathy.

Intracardiac thrombosis in patients with a dilated cardiomyopathy can be life threatening. This study investigated the incidence, risk factors, and outcome of intracardiac thrombosis in children with dilated cardiomyopathy. A retrospective review of the clinical records was performed in 83 children with dilated cardiomyopathy diagnosed from January 1995 to December 2008. Intracardiac thrombi were detected in 5 patients (6.0%). The intracardiac thrombi were found mainly in the left ventricle (n = 3). One patient had a thrombus in the left atrium at the time of diagnosis, and a right ventricular thrombus was found in 1 patient with unrepaired ventricular septal defect complicated by pulmonary hypertension. Intracardiac thrombosis developed during rapid deterioration of ventricular function, and all patients had a poor ejection fraction of the left ventricle. All patients were treated with heparinization, and thrombectomy was performed in 1 patient. Three patients achieved complete resolution of the thrombus without further embolic complications. Careful evaluation and aggressive anticoagulation are necessary for the prevention of intracardiac thrombosis in children with poor ventricular function, especially during rapid deterioration of ventricular function.

Closure of conduit fenestration after extracardiac Fontan procedure using Amplatzer vascular plug: comparison with detachable coil.

The objective of this study was to report the outcome of fenestration closure using either an Amplatzer Vascular Plug I or detachable coils in patients undergoing extracardiac Fontan procedure with conduit fenestration. We reviewed the medical records of 23 patients who underwent transcatheter closure of conduit fenestration with the extracardiac Fontan procedure. The median age at fenestration closure was 57 months (range 36 to 98). The median interval between the operation and the procedure was 28 months (range 8 to 68). The Amplatzer Vascular Plug I (AVP) was used in 16 patients, and detachable coils were used in 7 patients. In the coil group, we used 1 coil in 3 patients, 2 coils in patients, and 3 coils in 1 patient, all based on angiographic results. In the AVP group, we used a device that was at least 1 mm larger than the initial fenestration size. No immediate or long-term complications were associated with the procedure or with the closure devices. On final follow-up, 3 of 7 patients (43%) in the coil group had complete closure, and 17 of 17 patients (100%) in the AVP group had complete closure. The AVP showed good results for transcatheter closure of a conduit-type fenestration and was found to perform better than the detachable coil.