Intermediate-Term Results of Phase I Food and Drug Administration Trials of Buttoned Device Occlusion of Secundum Atrial Septal Defects☆

Abstract Objectives. This study was conducted to evaluate the intermediate-term results of the multi-institutional U.S. trial of the buttoned device for transcatheter closure of atrial septal defects (ASDs). Background. The trial was conducted in three centers (University of Arizona, University of Michigan and University of Wisconsin) under a Food and Drug Administration (FDA)-approved clinical trial with investigational device exemption. Only short-term follow-up is known. Methods. All 46 patients who had successful implantation of the device were prospectively followed up. Patients were evaluated at 1, 6 and 12 months after device occlusion and yearly thereafter. Results. This cohort was followed up from 51 to 68 months (mean 60.8, median 62). Patient ages ranged from 1 to 62 years (median 4); weights ranged from 10 to 105 kg (median 18); and stretched ASD sizes were 14 ± 4 mm (left to right shunts) and 10 ± 3 mm (right to left shunts). Of the 46 patients, 45 (98%) had effective occlusion of their ASD, and 34 (74%) had complete ASD closure. The incidence of residual shunts decreased from 65% (30 of 46 patients) at 1 month after device placement to 27% (12 of 45 patients) at last follow-up. All residual shunts were quantitated as trivial. Only two patients (4%) required reintervention for significant residual defects. There were no cases of endocarditis or thromboembolism in 224 patient-years of follow-up. Conclusions. In up to 5.5 years of follow-up, the buttoned device provided effective closure in 98% of patients in whom the device was successfully implanted. The incidence of residual shunts decreased during follow-up, and no instances of endocarditis or thromboembolism were observed.