OBJECTIVE: This study evaluated the effect of echocardiographic left ventricular (LV) diastolic dysfunction on acute congestive heart failure after transcatheter atrial septal defect (ASD) closure in elderly patients. BACKGROUND: Although there is concern that LV diastolic dysfunction develops acute congestive heart failure after ASD closure, limited information is available regarding the influence, especially in elderly patients with severe LV diastolic dysfunction. METHODS: Two hundred consecutive patients older than 60 years were divided into 3 groups according to echocardiographic LV diastolic dysfunction: severe (early diastolic mitral annular velocity [e'] <5.0 cm/s), mild (5.0≤ e' <8.0 cm/s), and normal (e' ≥ 8.0 cm/s). Changes in plasma B-type natriuretic peptide (BNP) levels were evaluated. RESULTS: No patients with severe LV diastolic dysfunction developed acute congestive heart failure immediately after the procedure. BNP levels unchanged after the procedure in patients with severe LV diastolic dysfunction (126 ± 181 to 131 ± 148 pg/ml, P = 0.885), and this increase in BNP levels was not different from that between the diagnosis of ASD and the procedure. The change in BNP levels in patients with severe LV diastolic dysfunction, who were frequently treated with diuretics before the procedure, was equivalent to that in patients with mild LV diastolic dysfunction and normal LV diastolic function (5 ± 119 vs. 16 ± 101 vs. 9 ± 131 pg/ml, P = 0.724). CONCLUSIONS: Our findings suggest that transcatheter ASD closure under volume management is safe and valuable in elderly patients with echocardiographic severe LV diastolic dysfunction.