Page 29 - Journal of Structural Heart Disease Volume 1, Issue 3

135
Original Scientific Article
the clip is released. The TEE evaluation is repeated once more and if there is significant residual MR and no significant gradient (>6mmHg) additional clips can be deployed. These are deployed in the previ- ously described manner with one key difference— subsequent clips are passed through the valve in a closed position and opened below the valve in the ventricle. Placement of additional clips carries a risk of worsening MR (due to deformation of the leaflets), clip interaction and potential instability, and signifi- cant stenosis. In our experience, it is technically more challenging to place additional clips medial to the first clip. As such, when reviewing echo images prior to the procedure and expecting the need for multiple clips, or if considering an additional clip during the procedure, we aim to place the first clip in the more medial position and all subsequent clips laterally. An inherent advantage of the MitraClip procedure is the ability to remove a clip following closure and subse- quent assessment. Accordingly, if the operator is dis- satisfied with the result of an additional clip this can simply be opened, detached from the leaflet, brought back into the guide, and removed from the body.
The MitraClip procedure is generally safe and well tolerated. Aside from the risks associated with gener- al anesthesia, those specific to the procedure include: femoral venous complications; trans-septal trauma resulting in an atrial septal defect (significant shunts may require closure), left atrial perforation (care must be taken to manipulate the guide catheter away from the posterior wall of the left atrium prior to removal); clip detachment and embolization (clip stability must be assessed fluoroscopically and via echocardiogra- phy prior to final release of the clip); and endocarditis. The overall rate of such adverse events in our experi- ence is less than 1%.
Conclusion
The MitraClip procedure is a safe and effective ap- proach to reduction of MR with proven durability and clinical improvement. The safety of the procedure is attributable to two key elements. Firstly, the per- cutaneous trans venous access, which limits the significance of vascular complications compared to an open surgical approach. Secondly, the trans septal approach, which is a far less invasive method of ac- cessing the mitral valve compared to surgical access via the left atrium.
In the United States, the FDA has approved the MitraClip device for treatment of high risk patients with primary MR. The currently enrolling randomized COAPT study will help address the question regarding the benefit of MitraClip in conjunction with guideline directed medical therapy when compared to stan- dard care in high risk patients with FMR. Furthermore, the question of long-term, sustained reduction of MR and persistent clinical improvement remains to be addressed with longer duration of follow up. Based on the impeccable safety profile of the procedure and demonstrated medium-term clinical durability, future studies should be aimed at the evaluation of MitraClip for treatment of patients with severe prima- ry or functional MR deemed moderate, or indeed low risk, for surgery.
Conflict of Interest
Dr. Saibal Kar is a proctor for MitraClip.
Comment on this Article or Ask a Question
References
1. Carpentier A. Mitral valve annuloplasty. Ann Thorac Surg. 1990;49:508-509. PMID: 2310267
2. Alfieri O, Maisano F, De Bonis M, Stefano PL, Torracca L, Oppizzi M, et al. The dou- ble-orifice technique in mitral valve repair: A simple solution for complex problems. J Thorac Cardiovasc Surg. 2001;122:674-681. PMID: 11581597
3. Ling LH, Enriquez-Sarano M, Seward JB, Tajik AJ, Schaff HV, Bailey KR, et al. Clinical out-
come of mitral regurgitation due to flail leaf- let. N Engl J Med. 1996;335:1417-1423. DOI: 10.1056/NEJM199611073351902
4. Enriquez-Sarano M, Nkomo V, Mohty D, Avierinos JF, Chaliki H. Mitral regurgita- tion: Predictors of outcome and natural history. Adv Cardiol. 2002;39:133-143. DOI: 10.1159/000058920
5. Enriquez-Sarano M, Akins CW, Vaha- nian A. Mitral regurgitation. Lancet. 2009;373:1382-1394. DOI: 10.1016/S0140-
6736(09)60692-9
6. Nishimura RA, Otto CM, Bonow RO, Car- abello BA, Erwin JP, 3rd, Guyton RA, et al. 2014 AHA/ACC guideline for the man- agement of patients with valvular heart disease: A report of the American College of Cardiology/American Heart Associa- tion Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63:e57-185. DOI: 10.1161/CIR.0000000000000029
7. Vahanian A, Alfieri O, Andreotti F, Antunes
Sharma, R.A. et al.
An Overview of the MitraClip Procedure