Left Atrial Thrombus after Transcatheter Mitral Edge-to-edge Repair in a Patient with Left Appendage Occlusion.

A 67-year-old man with a history of heart failure (HF) secondary to ischemic cardiomyopathy, atrial fibrillation, and left atrial appendage occlusion (LAAO) developed worsening HF secondary to severe functional mitral regurgitation. Consequently, transcatheter edge-to-edge repair (TEER) was performed. Despite successful TEER, a large thrombus in the left atrium (LA) was unexpectedly discovered on postoperative day 3. Thrombus formation may be related to changes in the blood stream in the LA, endothelial injury by septal puncture, and an insufficient anti-thrombotic regimen. This case highlights the potential for the development of subacute LA thrombosis following TEER, even in patients with prior LAAO.