Atrial septal defect in Malta

OBJECTIVE: To study diagnostic and surgical trends in atrial septal defect (ASD) in a population-based study, and estimate birth prevalence and spontaneous closure rates. METHODOLOGY: All patients in Malta diagnosed as having ASD and born between 1990 and 1994 were identified from various sources. This took place in the setting of a regional hospital supplying diagnostic services for the entire population. Echocardiographic follow-up was also undertaken for lesions not requiring intervention. RESULTS: A total of 190 patients born in this period were diagnosed as having ASD. Age at diagnosis and age at surgery have decreased significantly over the period under study (P < 0.0001). The mode of diagnosis has become entirely noninvasive, and the perioperative mortality decreased dramatically over time. For the period 1990-94, the incidence at birth for defects not requiring intervention was 2.0/1000 live births, defects requiring intervention 0.4/1000 live births. A total of 92% of 50 defects not requiring intervention closed spontaneously, and the remainder had spontaneously decreased in size on follow-up. CONCLUSIONS: ASD is a relatively benign malformation in which early and noninvasive diagnosis can be achieved, with an extremely low interventional mortality.