Elevated Left and Right Atrial Pressures Long-Term After Atrial Septal Defect Correction: An Invasive Exercise...

Background Despite correction of the atrial septal defect (ASD), patients experience atrial fibrillation frequently and have increased morbidity and mortality. We examined physical capacity, cardiac performance, and invasive hemodynamics in patients with corrected ASD. Methods and Results Thirty-eight corrected patients with isolated secundum ASD and 19 age-matched healthy controls underwent right heart catheterization at rest and during exercise with simultaneous expired gas assessment and echocardiography. Maximum oxygen uptake was comparable between groups (ASD 32.7±7.7 mL O₂/kg per minute, controls 35.2±7.5 mL O₂/kg per minute, P=0.3), as was cardiac index at both rest and peak exercise. In contrast, pulmonary artery wedge v wave pressures were increased at rest and peak exercise (rest: ASD 14±4 mm Hg, controls 10±5 mm Hg, P=0.01; peak: ASD 25±9 mm Hg, controls 14±9 mm Hg, P=0.0001). The right atrial v wave pressures were increased at rest but not at peak exercise. The transmural filling pressure gradient (TMFP) was higher at peak exercise among patients with ASD (10±6 mm Hg, controls 7±3 mm Hg, P=0.03). One third of patients with ASD demonstrated an abnormal hemodynamic exercise response defined as mean pulmonary artery wedge pressure ≥25 mm Hg and/or mean pulmonary artery pressure ≥35 mm Hg at peak exercise. These patients had significantly elevated peak right and left atrial a wave pressures, right atrial v wave pressures, pulmonary artery wedge v wave pressures, and transmural filling pressure compared with both controls and patients with ASD with a normal exercise response. Conclusions Patients with corrected ASD present with elevated right and in particular left atrial pressures at rest and during exercise despite preserved peak exercise capacity. Abnormal atrial compliance and systolic atrial function could predispose to the increased long-term risk of atrial fibrillation. Registration Information clinicaltrials.gov. Identifier: NCT03565471.