Transcatheter mitral valve repair with the MitraClip device has become an established therapeutic option for the treatment of symptomatic patients with mitral regurgitation and prohibitive surgical risk. Despite its safe profile when performed in experienced centers, complications such as MitraClip device detachment or migration into the left atrium can occur and pose a significant risk. We report a MitraClip device migration into the left atrium short after its placement in a patient with symptomatic mitral valve regurgitation and a history of previous coronary artery bypass grafting and aortic valve replacement.

acute heart failure, cardiac anatomy, management, medical management, mitral insufficiency, TEE

Mitral valve regurgitation, either of degenerative or functional origin, is a common structural heart disease, usually treated with valve repair or replacement using open heart surgery. A MitraClip (Abbot Vascular, CA, USA) is a clip device that is commonly used by interventional cardiologists for the correction of mitral regurgitation (MR) in patients deemed to be of increased surgical risk. The device has a dual-arm structure with grippers to capture the mitral valve leaflets and bring them together to reduce regurgitant blood volume on a beating heart. Although it was designed for degenerative MR related to primary leaflet abnormalities, several studies have shown that it is quite effective for functional MR from annular or ventricular distortion on high-risk surgical population.^[1] It is a minimally invasive technique usually performed in catheterization laboratories under transesophageal echocardiographic guidance; therefore, it lacks all the recognized complications of open-heart surgery and is especially friendly to high-risk populations such as the elderly and patients with various combinations of multiple comorbidities.^[2]

Although a single leaflet detachment is a recognized complication of the MitraClip mitral valve repair procedure, occurring in 4.9% of cases in the EVEREST II trial^[3] and in 0.2% in the German transcatheter mitral valve intervention (TRAMI) registry^{[4, 5]}, MitraClip device migration into left atrium is an extremely rare potential complication^[6], occurring due to inadequate tissue grasp between the MitraClip wing and the grippers. Parameters such as challenging anatomy or limitations in valvular imaging may be important contributors in the development of these complications.‌^[7] Although 3D transesophageal echocardiography is being increasingly used for the assessment of MitraClip placement, in our case, it is possible that the use of conventional imaging prohibited the adequate assess to clip anchoring.

MitraClip migration results in acute severe mitral regurgitation, with acute hemodynamic decompensation, requiring immediate medical support. Mitral valve surgery as salvage procedure is the only way forward in many cases after failed MitraClip device.^[8] As perhaps expected, the in-hospital and the one-year mortality rates are quite high after failed MitraClip procedures, fact that perhaps reflects the high-risk baseline profile of this specific patient group as indicated by an overview study by Melillo et al.^[9] The latter study demonstrated an in-hospital mortality rate of 15%, rate of postoperative strokes around 6%, and an all-cause death incidence after the first year of around 26.5%. On the other hand, another rare potential complication could be mitral stenosis resulting from inappropriate patient selection and unsuccessful sizing. The role of good planning and 3D transesophageal echo imaging in order to identify the pathology of the valve and the appropriate patient selection is well recognized.^[10]

MitraClip device migration is a very rare but unfortunately serious complication of the MitraClip mitral valve repair procedure. Correct sizing and good patient selection are of great importance in order to avoid complications. Our patient survived until he was taken to surgery with the support of inotropes, vasopressors, and intra-aortic balloon pump.