Temporary balloon occlusion test can overestimate the risk of acute pulmonary edema after transcatheter atrial septal defect closure

BACKGROUND: Atrial septal defect (ASD) closure can cause acute pulmonary edema. Before transcatheter closure is performed, temporary balloon occlusion test (BOT) is recommended in patients with left ventricular dysfunction to predict the risk of pulmonary edema. However, the accuracy of BOT has not been verified. This study aimed to compare hemodynamic differences between BOT and transcatheter closure. METHODS: A total of 42 patients with a single ASD over age 18 years who underwent BOT before transcatheter ASD closure between October 2010 and May 2020 were analyzed. Pulmonary capillary wedge pressure (PCWP) was measured using a Swan-Ganz catheter placed in the pulmonary artery at baseline, after 10 min of BOT, and after transcatheter closure. Amplatzer septal occluder was used for all transcatheter closures. RESULTS: Mean patient age was 64 ± 18 years (range, 18-78). Mean ASD diameter and pulmonary to systemic flow ratio were 18 ± 5 and 2.8 ± 1.0 mm, respectively. Mean PCWP at baseline, during BOT, and after transcatheter closure was 8.9 ± 2.9, 13.5 ± 4.2, and 9.5 ± 2.6 mmHg, respectively. The difference between BOT and after transcatheter closure values was significant (p < 0.001). During BOT, PCWP increased ≥18 mmHg in 7 patients, whereas after ASD closure, PCWP was <18 mmHg in all 7 and none developed acute pulmonary edema. CONCLUSION: Temporary balloon occlusion of an ASD and transcatheter ASD closure result in different hemodynamic change. BOT overestimates increase of PCWP after transcatheter ASD closure and requires careful interpretation. Well-designed, larger studies in higher-risk patients are warranted to verify the clinical implications of BOT in more detail.