Feng-Yu Kao

Arrhythmic burdens in patients with tetralogy of Fallot: A national database study

BACKGROUND Tetralogy of Fallot (TOF) is a common cyanotic congenital heart disease with increasingly recognized late morbidity. OBJECTIVE The purpose of this study was to explore the long-term outcome by using a national database of Taiwan, a country with national health insurance and easily accessible medical care. METHODS Data on TOF patients were retrieved from database records from 2000 to 2010. Complications and therapies were identified by their respective codes. RESULTS We identified 4781 TOF patients (prevalence 0.63/1000 in pediatric patients and 0.06/1000 in adult patients). Arrhythmias were identified in 219 patients (8.3% for adult patients and 2.8% for pediatric patients): 160 tachycardia and 59 bradycardia (4 with tachy-bradycardia syndrome). The occurrence of arrhythmias was associated with higher mortality (excluding cardiac surgical death, 15.6% vs 8.6%, P = .001). Patients with atrial fibrillation were the oldest (median age 44.3 years), followed by those with tachy-bradycardia syndromes (32.4 years) and atrial flutter (31.5 years). The incidence of nonperioperative tachycardia increased with age (1.4%, 1.7%, 3.3%, 5.2%, 10.2%, and 16.9% in age group 0-9, 10-19, 20-29, 30-39, 40-49, and ≥50 years, respectively). Tachycardia therapy (ablation and implantable cardioverter-defibrillator) was administered in 20.4% (annually 2.4%) of patients with nonperioperative tachycardia. In the subgroup born 2000-2010 with complete postnatal data, mortality was 15.1% (296/1960), and 1-, 5-, and 10-year survival was 0.911, 0.826, and 0.788, respectively. Risk of atrioventricular block requiring a pacemaker was 0.6%. CONCLUSION Arrhythmias are common in TOF patients and increase mortality risk. Medical needs because of tachycardia often appear late in adulthood.

Epidemiological profile of Wolff–Parkinson–White syndrome in a general population younger than 50 years of age in an era of radiofrequency catheter ablation

BACKGROUND The prevalence of Wolff-Parkinson-White (WPW) syndrome varies between 0.68 and 1.7/1000. The epidemiological profile may be modified after the introduction of transcatheter interventions. OBJECTIVES The aim of this study is to investigate the epidemiological trends of the WPW syndrome in a general population during a period with available and reimbursed transcatheter ablation. METHODS AND RESULTS Data of WPW patients <50 years old were retrieved from our national database (2000-2010). We identified 6086 (61% male) patients, accounting for an overall prevalence of 0.36/1000 with a peak of 0.61/1000 in ages 20-24 years. The risk of death and sudden death was 0.071% and 0.02% per patient-year, respectively. The 42 deaths occurred at a median age of 29 years. Associated congenial heart disease was noted in 158 (2.6%) patients, including 42 with Ebsteins anomaly that increased the mortality risk (P=0.001, OR=8.5). In those without congenital heart disease, myocardial dysfunction occurred in 115 (1.9%) patients and increased the risk of death (P<0.001, OR=10.6) and sudden death. Radiofrequency catheter ablation was performed in 2527 patients at a median age of 25.7 years (4.54% per patient-year, discharge mortality 0.16%); 11 (0.4%) before the age of 5, and 2231 (88%) after the age of 15. Whereas repeated ablation procedures accounted for 6.0% of the procedures, those in Ebsteins patients were 25%. CONCLUSION Radiofrequency catheter ablation is already a common treatment for WPW patients, particularly during young adulthood, which accounts for a lower prevalence. Myocardial dysfunction and associated congenital heart disease remain as risks of mortality.

Risk of Respiratory Syncytial Virus Infection in Cyanotic Congenital Heart Disease in a Subtropical Area.

OBJECTIVE To compare the risk of respiratory syncytial virus (RSV)-associated hospitalization and analyze the epidemiology of RSV infection in patients with cyanotic and acyanotic congenital heart disease (CHD), we analyzed the nationwide health insurance database from 2005-2010. STUDY DESIGN This study included 1050 patients with cyanotic CHD and 7077 patients with acyanotic CHD. Patients with acyanotic CHD were further classified into hemodynamically significant (hs)-acyanotic and non-hs-acyanotic groups according to whether they underwent surgery or took at least 2 anticongestive medications. RESULTS RSV-associated hospitalization was higher in the cyanotic group than in hs-acyanotic and non-hs-acyanotic groups both before 1 year of age (4.8% vs 2.1% vs 1.5%, P < .001) and between 1 and 2 years of age (0.9% vs 0.56% vs 0.14%, P = .003). The hospitalization duration, intensive care, ventilator support prevalence, hospitalization cost, and mortality rate were significantly higher in the cyanotic group than in the other 2 groups. Logistic regression revealed that cyanotic CHD was the most significant risk factor for the ventilator support and RSV-associated mortality. In both patients with cyanotic and acyanotic CHD, RSV-associated hospitalization rate was higher in patients aged younger than 1 year and in spring and autumn in Taiwan, a subtropical country. CONCLUSIONS The results show that patients with cyanotic CHD have a higher risk of severe RSV infection than do those with acyanotic CHD. RSV prophylaxis is more important and may reduce costs more for patients with cyanotic CHD.

Paradigm shift in the intervention for secundum atrial septal defect in an era of transcatheter closure: A national birth cohort study

BACKGROUND Secundum atrial septal defect (ASDII) is a common congenital heart defect, but the intervention, either transcatheter or surgical, needs are unclear. This study was to examine the paradigm shift in its intervention in an era of transcatheter closure. METHODS AND RESULTS The study birth cohort 2000-2008 (2,070,145 live births) with complete postnatal medical data was derived from the national database (2000-2014) of Taiwan, a country with national health insurance and easily accessible high-standard medical care. We found 5,515 patients with simple ASDII (median follow-up 12.2 years, one-third diagnosed after age 6 years, incidence 2.66/1,000 live births). Excluding patients with coexisting ventricular septal defect, ASDII intervention was performed in 1,435 of 4,585 patients: transcatheter closure in 1,080 (23.6%) and surgery in 355 (7.8%). The interventional need is 0.69 per 1,000 live births: 0.52 per 1,000 for transcatheter closure and 0.17 per 1,000 for surgery. In the era of transcatheter closure (July 2004-December 2014), ASDII intervention increased to 3.56-fold, but the number of operations decreased to half. The freedom from intervention was lower, and the age at intervention was younger (freedom from intervention at age 6 years, 0.749 vs 0.805, P < .001). In patients born in the era of transcatheter closure, 19.5% (108/555) of the intervention was surgery. Atrioventricular block occurred in 1.12% of those patients after transcatheter closure and none after surgery (P = .149). CONCLUSIONS In the era of catheter intervention, the interventional criteria for ASDII are less strict and one-third of the patients may receive intervention, mostly transcatheter closure, at the pediatric ages.

Postnatal Risk of Acquiring Kawasaki Disease: A Nationwide Birth Cohort Database Study

Objective To investigate the postnatal risk of Kawasaki disease and coronary complications from a nationwide birth cohort in Taiwan, a country with the third‐highest incidence of Kawasaki disease worldwide. Study design We enrolled children born between 2000 and 2009 with complete postnatal medical care records for 2000‐2014 in the Taiwan national database. Results Out of a total of 2 150 590 live births, we identified 6690 (62.6% boys) patients with Kawasaki disease. The onset was mostly (93.9%) within the first 5 years of life (median, 16 months; 38% during infancy), but was rare within the first 3 months of life. The overall cumulative incidence of Kawasaki disease by age 5 years was 2.78‰ (3.33‰ for boys and 2.17‰ for girls; P < .001) and exhibited an increasing trend with birth year (from 2.28‰ for 2000 to 3.67‰ for 2009). The incidence ratio was 1.535 in boys and 1.055 in each increasing year. Kawasaki disease recurred more often in younger patients (cumulative incidence, 2.3% in infants vs 1.7% in children aged 1‐4 years). Coronary complications occurred in 16.2% of the patients, including 4 cases of acute myocardial infarction (3 occuring during the acute stage and 1 occurring 5 years later). The probability of a major cardiac event (infarction, undergoing percutaneous coronary intervention or coronary artery bypass grafting, or death) by adolescence was 1.9%. Conclusions The postnatal risk of Kawasaki disease was 3‰‐4‰ and increased with every birth year. Patients with Kawasaki disease are at substantial risk for a major cardiac events during childhood.

Postnatal cumulative incidence of supraventricular tachycardia in a general pediatric population: A national birth cohort database study

BACKGROUND Supraventricular tachycardia (SVT) is a common pediatric tachycardia, but the true incidence is unknown. OBJECTIVE We sought to investigate the true postnatal incidence and its medical needs. METHODS We derived a birth cohort comprised children born between 2000 and 2008 who had complete postnatal medical data in the Taiwan National Health Insurance Database for the period from 2000 to 2014. RESULTS From 1,967,911 live births, we identified 2021 patients with SVT (51.6% men), accounting for an overall incidence of 1.03 per 1000 patient-years (Wolff-Parkinson-White syndrome accounted for 16.2%). The cumulative incidence was 0.06, 0.25, 0.45, 0.88, and 1.39 per 1000 patient-years by the age of 1 month, 1 year, 5 years, 10 years, and 15 years, respectively. Major congenital heart disease (5.3%; hazard ratio 6.66; 95% confidence interval 2.98-14.87) and cardiomyopathy (0.9%; hazard ratio 8.78; 95% confidence interval 3.39-22.78) were associated with mortality. In patients without major congenital heart disease, the cumulative incidence of SVT was 0.05, 0.22, 0.41, 0.84, and 1.33 per 1000 patient-years by the age of 1 month, 1 year, 5 years, 10 years, and 15 years, respectively. By the age of 15 years, the annual risk of death and sudden death was 0.13% and 0.01% per patient-year, respectively. Radiofrequency catheter ablation was performed in 173 patients at the median age of 11 years: 1.7% during infancy, 5.8% by the age of 5 years, and 31.8% by the age of 10 years. The probability of being free from receiving ablation by the age of 15 years was 83.4%. CONCLUSION This birth cohort study provides the true incidence of pediatric SVT and indicates that almost one-fifth of the patients with SVT have already received ablation in the pediatric ages.