“Mind the Grasp”

Corresponding Author

Although open heart surgery represents the gold standard treatment for severe mitral regurgitation, recent data demonstrated that up to 50% of symptomatic patients with severe mitral regurgitation are deemed not suitable for surgery because of high operative risk.¹ Consequently, percutaneous therapies (both repair or replacement) for mitral valve disease have gained more importance and have become valuable alternatives to surgery over the last years.² In this field, transcatheter edge-to-edge (TEER) has been demonstrated to be a safe and effective device and represents the most used transcatheter approach for mitral valve repair so far.³ Currently, 2 TEER devices are commercially available, namely, MitraClip (Abbott) and Pascal (Edwards Lifesciences). Despite the fact that most operators have now become familiar with both technologies, different complications may occur following TEER.^4,5 Among device-related complications, single-leaflet device attachment (SLDA), although rare, is the most common issue and describes a complete loss of connection between the clip and leaflet, whereas clip embolization is even more rare, accounting for <1% according to the Transcatheter Valve Therapy registry.⁶

In the case presented by Zhou et al⁷ in this issue of JACC: Case Reports, the patient experienced an ST-segment elevation acute myocardial infarction caused by late (2 weeks after the index procedure) clip embolization. The dislodged clip was successfully snared and externalized through a 20-F sheath introducer, and the flow in the right coronary artery was completely restored. The case has 3 rare features among the very few cases of clip embolization described so far: 1) the subacute/late onset, because usually both SLDA and clip embolization occur acutely/subacutely; 2) the dislocation into the aortic root, causing complete right coronary artery obstruction and, in turn, inferior ST-segment elevation acute myocardial infarction; and 3) a fully percutaneous clip removal through a transfemoral aortic approach.

Careful patient selection represents the very first step to prevent the risk of SLDA/clip embolization because, in most cases, such complications occur in complex leaflet lesions.⁸ However, in most cases, SLDA/clip embolization are consequences of insufficient leaflet grasping or, alternatively, derive from leaflet tearing/perforation. Consequently, in the procedural planning phase, proper clip selection is important not only to achieve mitral regurgitation resolution but also to avoid complications. The early experience with XTR clip arms seems to be associated with high procedural success but also with a higher rate of SLDA and leaflet damage.⁹ In general, tension on the leaflets should be avoided, especially in short, fragile, and calcific leaflets. The latest 4th generation of the percutaneous edge-to-edge mitral valve repair system, with wider clips arms that reduce the force on the leaflets and provide independent grasping, has been designed to reduce SLDA and to improve leaflet insertion. Alongside this, the role of the interventional imager is becoming more and more central as the procedures become more complex. In fact, optimal transesophageal echocardiography is of utmost importance to guide the entire procedure and for the decision making throughout the procedure, particularly for the clip assessment before its release (Figure 1). Specifically, alongside the assessment of residual mitral regurgitation and transvalvular gradient, 3 steps are critical to avoid SLDA/clip embolization: 1) a rotation check of the device and symmetry in the 3D surgical view to avoid asymmetric grasping; 2) a check of the whole grasping process in the biplane transesophageal echocardiography view, ensuring deep leaflet capture and insertion; and 3) avoidance of multiple leaflet clipping attempts and quick leaflet insertion assessment to avoid too long an evaluation while the clip is still connected to the delivery system, which may determine leaflet damage. Last-generation TEER devices with independent grasping/clasping features allow for the optimization of leaflet insertion, thereby reducing the chance of incomplete leaflet capture in properly trained operators.

Figure 1.

Percutaneous Edge-to-Edge Mitral Valve Repair System Decisional Algorithm: Issues to Be Considered Before Clip Release

LAPm = mean left atrial pressure; LAPv = peak left atrial pressure; LVP = left ventricle pressure; MR = mitral regurgitation; TEE = transesophageal echocardiography; TVG = trans-valvular gradient.

Last but not least, careful adhesion to the instruction for use during the final release process (including proper final arm alignment evaluation and check of the locking mechanism) is extremely important to complete the procedure while avoiding partial device opening.

Finally, although the improvement of techniques and technologies will play an important role in reducing the risk of complications, this case raises another important point for all centers aiming at performing structural heart disease interventions: the fundamental role of the multidisciplinary heart team, not only in the selection and planning of the best treatment for the patient but also for the management of complications that might be expected, especially in patients with complex disease/procedures.

Funding Support and Author Disclosures

Dr Russo has received a fellowship training grant from European Association of Percutaneous Cardiovascular Interventions, sponsored by Edwards Lifesciences. Dr Taramasso has received consultancy fees from Abbott Vascular, Edwards Lifesciences, Medtronic, Boston Scientific, CoreMedic, MEDIRA, HiD-Imaging, PiCardia, ReCross, Shenqi Medical, CardioValve, and Simulands, outside the submitted work.