Morphological assessments of deficient posterior-inferior rim for transcatheter closure of atrial septal defect

Objectives: This study aimed to determine morphological characteristics of deficient posterior-inferior rim for transcatheter atrial septal defect (ASD) closure success. Background: The feasibility of transcatheter closure of ASD with deficient posterior-inferior rim remains unclear. Methods: Of 869 patients with ASD who were scheduled transcatheter closure, 121 with posterior-inferior rim of <5 mm were included. Posterior-inferior rim morphologies were evaluated by transesophageal echocardiography. Results: One hundred six patients successfully underwent transcatheter closure, while 15 patients failed. These 15 patients had complete deficient posterior-inferior rim of 0 mm and/or a large defect of ≥38 mm. Multivariate logistic regression analysis showed that transcatheter closure failure was independently related to complete deficient posterior-inferior rim and a large defect of ≥38 mm. Incomplete deficient posterior-inferior rim of >0 to <5 mm was observed in 84 patients. All these patients successfully underwent transcatheter closure, except two patients with a large defect of ≥38 mm. Complete deficient posterior-inferior rim was observed in 37 patients. The frequency of complete deficient posterior-inferior rim was higher in patients who failed transcatheter closure (87% vs. 23%, p <.01), but transcatheter closure was performed successfully if the range of complete deficient rim was ≤30°. After the procedure, no adverse events occurred during a median follow-up of 24 months. Conclusions: Most patients with deficient posterior-inferior rim successfully underwent transcatheter closure. Transcatheter closure could be performed even in patients with complete deficient posterior-inferior rim if the range was partial. Our findings can help to identify candidates for transcatheter closure.