The influence of iatrogenic interatrial septum leaks after left atrial appendage closure on cardiac function test results.

Aim: Left atrial appendage occlusion (LAAO) is a technique for preventing thromboembolism in patients with atrial fibrillation and a high risk of irreversible bleeding. In some patients, a spontaneous iatrogenic transseptal leak (ITL) remains after LAAO. The aim of this study was to assess the correlation between ITL incidence and the results of cardiac function tests in patients who underwent LAAO.

Methods And Results: LAOO was performed in 62 consecutive patients using the Amplatzer Amulet. Before and 3 months after LAA occlusion, the 6-min walking distance (6MWD) test was performed in all patients and oxygen consumption assessment (VO ) was performed in 32. All patients had transesophageal echocardiography before and 3 months after LAAO to assess ITL incidence. The patients were divided according to the presence and absence of ITL and the subgroup of patients with heart failure (HF) were further analyzed. In patients with HF and ITL, an increased VO (12.8 ± 5.2 vs 15.3 ± 4.7; P < 0.05) and 6MWD (350.1 ± 77.4 vs 414.3 ± 70.6; P < 0.05) was observed after the procedure comparing to the results before the procedure. The 6MWD was also significantly higher in the patients with transseptal leaks in comparison to those without (P < 0.0001).

Conclusion: The presence of transseptal leaks after LAAO does not influence overall cardiac function test results. However, in patients with HF, there is an increase in oxygen consumption and 6MWD. These results indicate that ITLs in patients with HF decrease left atrial pressure, which is the key contributor to the symptoms of heart failure during physical activity.