Malattached septum primum and deficient septal rim predict unsuccessful transcatheter closure of atrial communications

Objectives Assess impact of malattached septum primum (MASP) on transcatheter closure of interatrial communications. Background Large defect size and deficient rims have been described as predictors for complications and unsuccessful device placement in closure of interatrial communications. MASP is an underappreciated morphologic atrial septal variation whose prevalence in isolated atrial communications and its influence on percutaneous device closure has not been systematically assessed. Methods We retrospectively evaluated echocardiographic data of 328 patients scheduled for percutaneous secundum atrial septal defect (ASD) and patent foramen ovale (PFO) closure between January 2006 and January 2013. In ASD patients, defect size was measured by balloon stretch diameter while the length of the surrounding rims was measured in standard transthoracic and transesophageal views. Furthermore, the distance between septum primum and septum secundum as it attaches to the left atrial roof was evaluated in both, ASD and PFO patients. Septal anatomy of patients with procedural failure was compared to the anatomy of patients in whom the procedure was successful. Results Transcatheter defect closure was successful in 131 (92.3%) of 142 ASD patients (32.3 years ± 24.7 years) and in all 186 PFO patients (49.6 years ± 16.2 years). Thirteen (4%) patients were found to have MASP (1.6 mm-13 mm). Smaller retroaortic rim, inferior rim, and the presence of a MASP were independently associated with procedural failure in ASD patients (P = 0.02, P = 0.03, and P = 0.003, respectively). Conclusion Smaller retroaortic and inferior rims, as well as MASP are independent risk factors for unsuccessful transcatheter ASD closure.