Utility of MitraClip XTR System in Percutaneous Edge-To-Edge Mitral Valve Repair for Severe Flail Leaflet.

Transcatheter mitral valve (MV) edge-to-edge repair provided alternative solutions to high surgical risk patients with degenerative MV regurgitation (MR) and patients with functional MR leading to symptomatic heart failure. However, the procedure cannot be performed in certain MV anatomy such as excessive mitral annular or leaflet calcification with coexisting stenosis or excessive flail leaflet with wide gap and width. The introduction of MitraClip XTR system with its extended arms provided a wider range of MV anatomies that can be treated with MV edge-to-edge repair. In this report, we present the successful treatment of excessive flail posterior leaflet with MitraClip XTR device. Copyright:

INTRODUCTION

Percutaneous edge-to-edge repair using the MitraClip device is approved for clinical use in severe degenerative mitral valve (MV) regurgitation (MR) in patients who are deemed high risk for surgery[1] and for moderate-to-severe functional MR leading to symptomatic heart failure despite goal-directed medical therapy.[2] Up until early 2018, only the MitraClip NT version has been available, characterized by 9-mm arm length. Given the fixed arm length, the ideal anatomy for successful grasping has included a flail width of <15 mm and a flail gap of <10 mm.[3]

Until recently, patients with more extreme anatomy with very large flail gaps may not be offered transcatheter repair due to potential inability to grasp the leaflets. We illustrate the successful treatment of MR with the third-generation MitraClip XTR system (Abbott Vascular, Santa Clara, California, USA) in a patient with an excessive flail leaflet that would otherwise be challenging to grasp using MitraClip NT.

CASE PRESENTATION

A 96-year-old active woman with subacute decompensated heart failure (New York Heart Association Class III), severe MR from a flail P2 segment, and a Society of Thoracic Surgeons risk score of 15% for repair and 22% for replacement was referred for transcatheter MV repair after heart team evaluation at Mayo Clinic.

Periprocedural transesophageal echocardiogram demonstrated challenging MV anatomy with 10-mm and 16-mm flail gap and width, respectively, and posterior mitral annular calcification with a mean gradient of 7 mmHg and systolic flow reversals on pulmonary vein Doppler [Figure 1]. The diastolic MV gradient was corresponding to increased flow across MV from severe MR. Preprocedure MV area was 4.1 cm2 by planimetry. Direct left atrial pressure (LAP) measurement demonstrated severe elevation with mean at 37 mmHg and giant v-wave at 92 mmHg.

Figure 1

Transesophageal echocardiogram showing the flail width (a) and flail gap (b) as well as the three-dimensional echocardiography showing severe flail P2 leaflet with multiple chordal ruptures (c). (d and e) Transmitral gradient and pulmonary vein systolic reversal at baseline respectively

Given the size of flail segment, we anticipated the need of two MitraClip XTR devices, which provide 5-mm wider grasp arms compared to the NT system. After deployment of the first MitraClip XTR in the medial portion of A2–P2, the mean diastolic gradient did not change significantly, but a significant reduction was observed in the directly measured left atrial v-wave to 70 mmHg. The residual lateral MR was treated with the second XTR clip [Figure 2] with remaining mild MR at the end. The mean diastolic gradient was stable. The patient had an excellent procedural outcome with an immediate substantial reduction in mean LAP and v-wave [Figure 3].

Figure 2

Transesophageal echocardiogram showing residual mild regurgitation after the two clips were deployed (a and b), with a good tissue bridge on three-dimensional echocardiography (c) and a stable position on fluoroscopy (d) with an unchanged gradient (e) and resolution of the pulmonary vein systolic reversals (f)

Figure 3

Massive left atrial v-wave in the setting of severe mitral valve regurgitation (left), with a significant reduction after placement of two MitraClip XTR devices and improvement in systemic arterial pressure (right)

The patient was discharged the next day without complications. On follow-up at 60 days, the patient symptoms improved to the New York Heart Association Class I.

DISCUSSION

This case highlights the emerging role of the newer-generation MitraClip XTR in MR secondary to excessive flail leaflets that otherwise cannot be treated with the older-generation MitraClip system or the current-generation NTR. The new XTR system broadens the spectrum of MR disease that can be treated with percutaneous edge-to-edge repair. MitraClip XTR with its additional 5-mm arm width is better suited for large flail with long and redundant leaflet, while restricted leaflets with smaller MV area, mildly calcified annulus and leaflet, or flail leaflets at the commissures of MV are best managed with the shorter arms provided with MitraClip NTR system [Figure 4 and Table 1].

Figure 4

MitraClip NTR and XTR systems. MitraClip XTR has 3-mm longer arms and 3 mm of additional grippers' length allowing 5-mm longer clip grasping length[4]

Table 1

Preferred mitral valve anatomy for MitraClip XTR and MitraClip NTR

	MitraClip XTR preferred	MitraClip NTR preferred
Longer flail/prolapse	+
Redundant tissue	+
Central jet	+
Large valve area	+
Presence of calcifications/ chordae at grasping area		+
Short leaflet		+
Commissural jet		+
Small valve area		+

+: Preferred device for specific anatomy

Early multicenter experience of percutaneous edge-to-edge repair with the extended arms of MitraClip XTR system showed encouraging results with more than 93% procedural success leading to residual MR of ≤2+ in those cases.[4]

The rate of single-leaflet detachment or leaflet injury with the XTR system was 2%–4%.[4] The risk of such complications could be further reduced by ensuring good tissue grasping without applying too much tension on the MV leaflets and apparatus. Continuous refinement of the percutaneous edge-to-edge repair systems such as introducing independent arm grasping[5] can potentially further improve the procedure and increase its success.

CONCLUSION

The use of MitraClip XTR can be considered in nonsurgical patients with excessive flail MV leaflets that otherwise cannot be treated with the limited arm width provided by the NTR system. The anatomical limitations of percutaneous edge-to-edge repair system constantly being redefined with continuous refinement of transcatheter MV devices.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.