Abstract 17670: Double Trouble: Exploring the Rare Coexistence of Right and Left Atrial Thrombus After Left Atrial Appendage Ligation and Maze Procedure

Abstract

Introduction: Left atrial appendage (LAA) harbors around 90% of thrombus in patients with Atrial Fibrillation(AF) related strokes. Incomplete surgical ligation and LAA stump are independent risk factors for stroke and thromboembolism in AF patients. To our knowledge, we report the first case of biatrial thrombus occurring within 1 week of surgery. Case Presentation: A 76-year-old man with Paroxysmal AF and three-vessel coronary artery disease presented with 3-week exertional and resting shortness of breath and chest pain. Troponins were negative, and EKG revealed AF. Cardiothoracic surgery planned coronary bypass, MAZE procedure, and LAA clipping. Intra-operative transoesophageal echocardiogram(TEE) showed ejection fraction of 35% without LAA clot. Post-operatively, despite anticoagulation(AC) and beta blocker therapy, AF recurred within a week. Subsequent TEE prior to anticipated cardioversion(CV) revealed thrombus on the superior vena cava border of right atrium, anterolateral wall of left atrium and near the mitral valve annulus. CV was deferred, and he was sent to rehab with AC. We hypothesize that the thrombus may be attributed to a stunned atrium caused by ischemic myocardial injury. Our case underscores the need for heightened suspicion of thrombus in individual cases. Discussion: Left atrial appendage occlusion (LAAO) was implemented as stroke prophylaxis strategy in AF during surgical interventions like maze and coronary bypass. while the European Society of Cardiology advises continuing AC after LAAO, studies suggest discontinuing AC in high-risk bleeding patients after successful surgical AF ablation and LAAO if sinus rhythm is maintained for ≥3 months. LAAOS III study shows economic benefit of concomitant surgical LAAO during cardiac surgery in AF patients with CHA2DS2-VASc score ≥2 for stroke prevention. When used alongside AC, it offers incremental benefits. Safety of discontinuing AC after LAAO requires further investigation.