Prevalence and Determinants of Incomplete Right Atrial Reverse Remodeling After Device Closure of Atrial Septal Defects

Whether the relief of chronic right atrial (RA) volume load by device closure of an atrial septal defect (ASD) normalizes RA size is unknown. The present study evaluated the prevalence and determinants of incomplete RA reverse remodeling (RAR) after ASD closure in adults. Transthoracic echocardiography was performed in 44 consecutive patients with secundum ASD (age 43 ± 17 years, 10 men) without a history of atrial arrhythmia shortly before and at 3 months after device closure of ASD. The pulmonary/systemic flow ratio was derived using invasive oximetry. The RA size had significantly decreased at 3 months of follow-up (RA volume index [RAVI] 52 ± 29 to 27 ± 17 ml/m2, p <0.001). Incomplete RAR (defined as a RAVI of ≥21 ml/m2) was detected in 25 patients (57%) after closure. They were older, had a larger pulmonary/systemic flow ratio, a higher pulmonary arterial systolic pressure, more tricuspid regurgitation, and larger RA, left atrial, and right ventricular sizes before closure than those with a normalized right atrium. Before closure, RAVI was the only independent determinant for incomplete RAR (odds ratio 1.115, 95% confidence interval 1.019 to 1.220; p = 0.018). A cutoff value of RAVI of ≥40 ml/m2 has a sensitivity of 84% and specificity of 72% in the receiver operating characteristic curve. The preclosure RAVI correlated moderately with the shunt-duration index, calculated by multiplying the age to pulmonary/systemic flow ratio (r = 0.64, p <0.01). In conclusion, incomplete RAR occurred in >1/2 of the adult patients at 3 months after ASD device closure and was related to excessive preclosure RA dilation.