The relationship between incomplete surgical obliteration of the left atrial appendage and thromboembolic events after mitral valve surgery (from the ISOLATE Registry)

Left atrial appendage (LAA) is a common site of thrombus formation especially in patients with atrial fibrillation (AF). Complete surgical LAA closure (cSLC) is the surgical aim, however incomplete surgical LAA closure (iSLC) is not rare. In this study, we aimed to evaluate the risk of thromboembolic complications (TEC) in AF patients with iSLC after mitral valve surgery. A total of 101 AF patients (mean age: 61.8 ± 11.8 years; male:32), who underwent surgical suture ligation during mitral valve surgery were enrolled in this retrospective study. All patients underwent transthoracic and transesophageal echocardiography (TEE) at least 3 months after surgery. The primary outcome was the occurrence of TEC including any ischemic stroke, transient ischemic attack, coronary or peripheral embolism. TEE examination revealed cSLC in 66 (65.3%) and iSLC in 35 patients (34.6%). A total of 12 TECs (11.9%) occurred during a mean follow-up time of 41.1 ± 15.6 months. TECs were found to be significantly higher in the iSLC group (25.7% vs 4.5%, p = 0.002). The prevalence of iSLC was significantly higher in patients with TEC (75 vs. 29.2%, p = 0.002). High CHA₂DS₂-VASc Score and iSLC were found to be independent predictors of TEC. Long term TEC free survival was found to be significantly decreased in patients with iSLC. The presence of iSLC was associated with a significantly increased risk of TEC in AF patients after mitral valve surgery. Routine intraoperative and postoperative screening for iSLC by TEE and long-term strict anticoagulation therapy are recommended in these patients.