Improvement in exercise capacity in asymptomatic and mildly symptomatic adults after atrial septal defect percutaneous closure

Controversy exists as to whether secundum atrial septal defects (ASDs) in asymptomatic or mildly symptomatic New York Heart Association (NYHA) class I or II adult patients should be closed. Thirty-seven patients (24 females; mean age 49.4 years, range 19 to 76) with a mean pulmonary to systemic flow ratio (Qp:Qs) of 2.1 (1.2 to 3.4) had a maximal oxygen uptake (VO2max) determination and echocardiographic measurement of right ventricular dimensions before and 6 months after elective percutaneous closure of ASD. At baseline, mean VO2max was 23.5+/-6.4 mL/kg per minute and was higher in the 15 NYHA I patients than in the 22 NYHA II patients (27+/-6.9 versus 20.8+/-4.6 mL/kg per minute; P=0.0015). VO2max increased significantly at 6 months (23.5+/-6.4 to 26.9+/-6.9 mL/kg per minute; P