Large atrial thrombus formation after MitraClip implantation: is anticoagulation mandatory?

Percutaneous mitral valve repair with the MitraClip system has evolved as a promising new technique for the non-surgical treatment of mitral regurgitation (MR). To date, few major adverse events have been reported in initial studies with this technique. The case is reported of a 70-year-old patient who underwent successful MitraClip implantation. Routine pre-discharge transesophageal echocardiography on day 5 after implantation showed large thrombus formation in the left atrium (posterolateral wall) and on the right atrial side of the septum. The patient had not received any anticoagulation after clip implantation, and did not have any monitored episodes of atrial fibrillation prior to the scheduled discharge day. It is concluded that mandatory anticoagulation for at least one month should be considered in patients undergoing MitraClip implantation.