Survival analysis of Down syndrome with congenital heart disease: a 5-years registry at QSNICH.

BACKGROUND: Down syndrome (DS) is the most common chromosomal abnormality in children. Atrio-ventricular septal defect (AVSD) is the most common congenital heart disease (CHD) reported in DS. The mortality rate of DS with congenital heart disease (CHD) is 5-7 times higher than normal population. The survival rate in DS has improved with time and has reported up to 91% and 85% at one and ten years of age, respectively.

OBJECTIVE: To study the prevalence of CHD, clinical course, treatment, the overall survival in patients with DS compare with those who are associated with CHD.

STUDY DESIGNS: DS registry, multidisciplinary approach, single centre.

MATERIAL AND METHOD: All DS patients at QSNICH with parental signed consent were enrolled in the registry. The study was conducted for 5 years starting from May 2007 to April 2012. All patients were followed-up according to schedule modified from American Academic of Pediatrics (AAP) health supervision guideline. Standard treatment was given to all those children with diagnosis of CHD and/or other associated diseases.

RESULTS: Four hundred and two cases of DS were enrolled. Two cases were excluded due to the parental inconvenience. The mode and mean age of the patients at registration were 1 and 7 months (1-62). Two hundred and seventy-one cases had an initial echocardiographic diagnosis of CHD, which included 91 of Patent ductus arteriosus (PDA), 49 of Ventricular septal defect (VSD), 34 of AVSD, 34 of secondum Atrial septal defect (ASD), 6 of Tetralogy of Fallot (TOF), 2 of Coractation of Aorta (CoA), 11 of other CHD and 44 of combined lesions. During the follow-up period, spontaneous closure of PDA, VSD and ASD occurred in 46, 12 and 15 cases, respectively. After the exclusion of those who had spontaneous closure, the prevalence rate of CHD in DS was 49.8%. VSD was the most common lesion, slightly more than PDA. Ninety-eight cases underwent cardiac surgery; including 39 of associated VSD, 24 of AVSD, 26 of PDA, 3 of TOF, 4 of CoA/AA repaired, one each of Cor triatriatum and primum ASD. Twelve cases had catheter interventions, including PDA occlusion (10 cases), and 1 case of balloon dilatation of re-CoA and coils embolization of isolated major aorto-pulmonary collateral artery. Seven cases were lost at follow-up. By using the hospital information and National Health Security Office (NHSO) database, 47 infants died during the follow-up period. The causes of death were immediate post cardiac surgery in 10 cases (AVSD in 9, VSD in 1) and not associated with surgery in 37 cases including CHF in 8, pneumonia in 7, leukemia in 4, airway disease in 3, others 7 and unknown 8 cases. The overall survival at 1 and 5 years of age were 96% and 86%, respectively. DS with CHD had a significantly lower survival rate than those without CHD (p < 0.001).

CONCLUSION: According to this study, the prevalence rate of CHD in DS was high. VSD was the most common lesion and has better prognosis than AVSD. The main cause of death was a cardiac problem. Follow-up patients by using modified AAP guideline and standard treatment can improve their overall survival.