Left atrial function after thoracoscopic left atrial appendage exclusion as standalone and as combined with epicardial atrial fibrillation ablation: echocardiographic findings at one- year follow up

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. INTRODUCTION: Left atrial appendage (LAA) is the most common source of thrombi in patients with atrial fibrillation (AF). The Totally Thoracoscopic (TT)-LAA exclusion with epicardial clip is an effective procedure, however the effects on left atrial (LA) function remain unknown. PURPOSE: The aim of this study was to assess the impact of TT-LAA exclusion on the LA function in patients undergoing to standalone TT-LAA exclusion and patients received combined procedure, namely: TT-LAA exclusion and Thoracoscopic Epicardial Ablation (TEA). METHODS: 39 AF Patients underwent to TT-LAA exclusion with the clip. Indication to standalone TT-LAA exclusion was: high risk for ischemic stroke or contraindication to long-term anticoagulant therapy. All patients were screened preoperatively with 3D CT scan, transthoracic and trans-esophageal echocardiography. Intraoperative clip positioning and LAA exclusion were guided by trans-esophageal echo. To evaluate LA function, standard transthoracic echocardiography and 2D strain of LA were performed before surgery, at discharge (3-4 days after the procedure), at 3-month and at 1 year. Routine blood tests and BNP levels were also measured. RESULTS: The study enrolled 39 consecutive patients, 25 underwent to standalone TT-LAA exclusion (mean age 78.6 ± 5.7 years, 79% males), and 14 LAA exclusion during TEA (mean age 64.5 ± 8.2 years, 82% males). The mean CHA2DS2-VASc and HASBLED scores were 3.5 and 2.1 respectively. Baseline characteristics are summarized in Figure 1. There were no major complications during the procedure. At median follow-up of 13 months, 1 non cardiovascular death, 1 ischemic stroke and 4 cardiovascular hospitalizations occurred. At 2D strain of LA, the reservoir function decreased significantly after clip implantation and recovered at 3-months follow-up; at 1 year it remained stable. Furthermore, NT-proBNP increased significantly after LAA exclusion with a return to baseline after 3 months. Changes in E/A occurred at predischarge and did not persist at follow up. Echocardiographic findings are summarized in Figure 2. Patients with indication to TEA and LAA exclusion presented a lower LA volume and a lower strain value. CONCLUSION: The main findings of this study can be summarized as follows: 1) The amputation of LAA is a safe procedure at long term follow up. 2) LAA amputation with the clip is associated with acute elevation of BNP levels the days after the procedure with return to baseline at 3 months and one year. 3) LAA amputation impairs the LA reservoir function after the procedure, with recovery after 3 months and remains preserved at one-year. This occurs either when LA strain is measured in sinus rhythm or in AF. 4) LAA exclusion results in a change in E/A that does not persist at three months follow-up and at 1 year. 5) Patients with indication to epicardial AF ablation and LAA exclusion present a lower LA volume with a lower strain value than patients undergoing standalone TT-LAA exclusion. [Figure: see text] [Figure: see text]