Transcatheter Tricuspid and Mitral Valve Edge-to-Edge Repair: The Double Double Orifice.

Introduction

Severe tricuspid regurgitation (TR) is a common comorbid condition in patients with left-sided valve disease and is an independent predictor of mortality. The presence of significant TR portends worse prognosis after successful surgical treatment of mitral regurgitation (MR).2, 3 Therefore, the American Heart Association/American College of Cardiology guidelines recommend concomitant tricuspid annuloplasty repair during left heart surgery for severe TR (Class I) and for any degree of TR with evidence of right ventricular annular dilatation or right heart failure (Class IIa).

As transcatheter therapies for mitral valve disease evolve, so too does the need to address associated TR using percutaneous techniques. The MitraClip system (Abbott Vascular, Santa Clara, CA) was approved in 2013 for transcatheter mitral valve repair for severe symptomatic primary MR in patients at prohibitive surgical risk (Class IIb). Observational studies of patients undergoing transcatheter mitral valve repair demonstrate worse clinical outcomes and higher mortality among patients with baseline grade III or IV TR.5, 6, 7 More recently, case series have demonstrated the potential feasibility and safety of transcatheter tricuspid valve repair using the MitraClip system for severe symptomatic TR in inoperable patients on a compassionate use basis.8, 9, 10 We present a case of double-valve mitral and tricuspid repair using the transcatheter edge-to-edge technique with emphasis on intraprocedural transesophageal echocardiographic guidance relevant to tricuspid valve intervention.

Case Presentation

An 83-year-old woman with biventricular dysfunction presented with dyspnea, orthopnea, and generalized anasarca in the setting of severe MR and TR. She had a history of coronary artery bypass surgery, transcatheter aortic valve replacement with a self-expanding prosthesis and subsequent pacemaker implantation, pulmonary hypertension, chronic atrial fibrillation on oral anticoagulation, type 2 diabetes, and stage 3 chronic kidney disease. She endorsed progressive New York Heart Association class IV symptoms requiring admission for acute decompensated heart failure. Her comorbidities, frailty, need for redo sternotomy, and calculated Society of Thoracic Surgeons mortality risk of 20% for mitral valve repair placed her at prohibitive surgical risk. Therefore, a decision was made by the heart team for percutaneous dual edge-to-edge valve repair.

Transthoracic echocardiography demonstrated moderate to severe (3+) MR due to mixed myxomatous thickening and functional tethering with effective regurgitant orifice area (EROA) of 0.33 cm2, regurgitant volume of 62 mL/beat, and pulmonary vein systolic flow reversal (Figure 1, Video 1). There also was severe (4+) TR with vena contracta width of 0.68 cm, aliasing radius of 0.91 cm, and resultant EROA of 0.40 cm2, hepatic vein systolic flow reversal, and plethoric inferior vena cava (Figure 2, Video 2). Her transcatheter bioprosthetic aortic valve was functioning normally with peak and mean gradients of 13 and 6 mm Hg, respectively. Both ventricles were dilated with reduced systolic function, with left ventricular ejection fraction of 36% and tricuspid annular plane systolic excursion of 1.3 cm. Right ventricular end-diastolic basal dimension measured 4.8 cm. Preprocedural transesophageal echocardiography confirmed these findings (Figure 3, Videos 3 and 4). The right ventricular pacemaker wire was situated between the posterior and septal leaflets, remote from the central TR jet, and therefore excluded leaflet impingement by the pacemaker wire as the predominant mechanism of TR.

Figure 1

Moderate to severe (3+) MR as seen in (A) parasternal long-axis, (B) four-chamber, (C) three-chamber, and (D) two-chamber windows. Except where otherwise specified, the Nyquist range used for all color flow Doppler was ±55–66 cm/sec.

Figure 2

Severe (4+) TR as seen in (A,B) four-chamber, (C) basal short-axis, and (D,E) right ventricular inflow views. (F) The vena contracta (v.c.) and aliasing radius of flow convergence measured 0.68 and 0.91 cm, respectively, with calculated EROA of 0.40 cm2, using an aliasing velocity of −28.9 cm/sec. PISA, Proximal isovelocity surface area.

Figure 3

Baseline MR and TR as seen in (A,B) four-chamber and (C) three-dimensional views on transesophageal echocardiography. The leaflets of the tricuspid valve can be visualized en face (D) in transgastric short-axis window or (E) by three-dimensional imaging. The pacemaker wire (PPM; white arrowhead) can be seen between the posterior and septal leaflets (D,E) and appears to be discrete from the central TR jet (C,D). A, Anterior; AoV, aortic valve; MV, mitral valve; P, posterior; TV, tricuspid valve; S, septal.

Intraprocedural Imaging by Transesophageal Echocardiography

The transcatheter edge-to-edge technique for mitral valve repair has been discussed previously. Transseptal access was obtained under transesophageal echocardiographic guidance, and one MitraClip was successfully placed, bringing together the A2-P2 scallops of the mitral valve, resulting in mild (1+) residual MR with resolution of pulmonary vein systolic flow reversal (Figure 4, Video 5). Attention was then turned to the tricuspid valve.

Figure 4

MR (A) before and (B,C) after successful MitraClip implantation on A2-P2 scallops. (A) Biplane imaging of the ME (B) bicommissural (approximately 60°) and (C) long-axis views (approximately 150°) are commonly used to visualize the mitral valve leaflet anatomy and successful edge-to-edge grasp of the leaflets. AMVL, Anterior mitral valve leaflet; AoV, aortic valve; LAA, left atrial appendage; PMVL, posterior mitral valve leaflet.

As with the mitral valve, preprocedural analysis of the tricuspid valve and localization of the regurgitant jet were performed using biplane imaging. A modified basal short-axis tricuspid inflow-outflow view (approximately midesophageal [ME] 60°–90°) visualizes the posterior and anterior leaflets, with the anterior leaflet adjacent to the aortic root and interatrial septum (Figure 5, Video 6). With the transducer aligned precisely along the commissures between the anterior-septal leaflets and the posterior-septal leaflets by adjusting the omniplane angle, a small central segment of the septal leaflet may be visible such that all three leaflets are visualized along the plane of the transducer, posterior-septal-anterior from left to right of the image. This is the tricuspid valve equivalent of the bicommissural view of the mitral valve, allowing the imager to precisely localize the regurgitant jet. Color Doppler identifies the region of regurgitant flow convergence by visualizing the proximal isovelocity surface area. The flow direction is also parallel to the transducer in this window such that the right ventricular systolic pressure and the gradient across the tricuspid valve can be measured using continuous-wave Doppler with reasonable confidence.

Figure 5

(A) The delivery catheter (arrow) in the right atrium is directed toward the tricuspid valve in a modified basal short-axis tricuspid inflow-outflow window (ME 90°, plane represented by the red line in panel B) that visualizes all three leaflets of the tricuspid valve, posterior-septal-anterior from left to right of the image. (B,C) Biplane imaging (yellow line) of the inflow view can visualize two of the leaflets in profile in an inverted four-chamber “grasping” view (ME 180°, plane represented by the green line in panel B). (C) The septal and anterior leaflets are seen here in profile with the clip apparatus (blue arrowhead) being maneuvered out of the delivery catheter toward its intended leaflets. The pacemaker wire (PPM; white arrowhead) can be seen between the posterior and septal leaflets on the inflow view. A, Anterior; AoV, aortic valve; IAS, interatrial septum; LA, left atrium; MC, MitraClip; MV, mitral valve; P, posterior; RA, right atrium; TV, tricuspid valve; S, septal.

Biplane imaging of the tricuspid inflow, resulting in an inverted four-chamber view at approximately ME 150°–180°, visualizes the leaflets coapt in profile in a “grasping” view (Figure 5C, Video 6). With color Doppler on, the biplane cursor is swept from left to right of the inflow image, from posterior-septal to anterior-septal coaptation regions (Figure 6). Visualizing the proximal isovelocity surface area corresponds to the region of regurgitation flow convergence by which to target the intended grasp. Color Doppler is then removed to visualize the underlying leaflet anatomy to determine its suitability for clip grasp (i.e., adequate coaptation depth, lack of calcium on leaflet tips, location of pacemaker or defibrillator wire if present) before proceeding to edge-to-edge intervention.

Figure 6

Biplane imaging of the inflow view identifies the predominant regurgitant jet by color Doppler and visualizes the underlying leaflet anatomy in the perpendicular “grasping” view. The (A) posterior-septal leaflet and (B) septal-anterior leaflet coaptation planes demonstrate the central TR jet seen at both commissures and the pacemaker wire (PPM; white arrowhead) between the posterior-septal commissure. A, Anterior; P, posterior; PPM, pacemaker; S, septal.

Following clip deployment on the mitral valve, the guide catheter was withdrawn into the right atrium and steered toward the tricuspid valve in a modified bicaval view (approximately ME 80°–100°) transitioning to the tricuspid inflow view (ME 60°–90° as described above) for clip positioning. The clip is visualized above the leaflets and aligned over the regurgitant jet (Figure 7). Functional TR usually manifests as a large central jet, as was the case here. The clip is preferentially placed between the septal-anterior leaflets or, less commonly, the septal-posterior leaflets for the reason that tricuspid annular dilatation occurs outward in the direction of the lateral right ventricular free wall. In this case, the clip is aligned over the anterior-septal leaflets in the region of the regurgitant jet. The clip arms are visualized open in the biplane “grasping” view (four-chamber ME 0° or its right invert 160°–180°). The proper orientation of the clip perpendicular to the line of coaptation is confirmed in transgastric short-axis (approximately 30°) or by real-time three-dimensional imaging. When properly positioned and oriented, the clip is then lowered just below the leaflets into the right ventricle, taking care to avoid the chordal apparatus, and pulled up for leaflet grasp. As with the mitral valve, the presence of a tissue bridge, adequate leaflet insertion, and clip stability are confirmed in multiple views and with real-time three-dimensional imaging (Figure 7, Videos 7 and 8). Transtricuspid gradient is obtained using continuous-wave Doppler to avoid significant tricuspid stenosis, defined as <5 mm Hg for native valves.

Figure 7

The clip is opened above the anterior and septal leaflets and oriented perpendicular to the coaptation line as seen in (A) biplane and (B) three-dimensional (3D) images. The pacemaker wire (white arrowhead) can be seen in 3D images moving to one side of the clip and does not appear to be entangled in the clip apparatus. The clip is positioned over the regurgitant jet, seen here in (C) four-chamber and (D) 3D views. (E) Successful grasp of the anterior and septal leaflets is confirmed in the inverted four-chamber view. (F) The presence of a tissue bridge can be visualized in 3D view. The pacemaker wire (white arrowhead) can be seen moving freely adjacent to the clip (blue arrowhead). A, Anterior; AoV, aortic valve; MV, mitral valve; P, posterior; S, septal.

In this patient, one clip was successfully placed in the tricuspid position between the anterior and septal leaflets to avoid impingement of the pacemaker wire that remained within the posteroseptal commissure (Figure 8, Video 9). A two-grade reduction in TR grade from severe (4+) to moderate (2+) was achieved (Video 10), with resolution of hepatic vein systolic flow reversal. The mean transtricuspid gradient after edge-to-edge repair was 2.0 mm Hg at a heart rate of 70 beats/min. Successful edge-to-edge repair of both valves was confirmed by three-dimensional visualization of double double-orifice valves (Figure 9, Video 11).

Figure 8

(A) One MitraClip was successfully implanted in the tricuspid position between the anterior and septal leaflets with moderate (2+) residual TR. (B) The double-orifice valve with tissue bridge is visualized in three-dimensional images with and without color Doppler flow in systole and diastole, respectively. The pacemaker wire (white arrowhead) is seen in the posterior orifice, unrestricted by the clip (blue arrowhead). (C) Mean transtricuspid gradient of 2.0 mm Hg is acceptable. A, Anterior; P, posterior; S, septal; TV, tricuspid valve.

Figure 9

Two double-orifice valves are visualized in three-dimensional images, and clip stability is confirmed in the four-chamber view. The clips (blue arrowheads) can be seen separate from the pacemaker wire (PPM; white arrowhead), which remains within the posterior-septal commissure. A, Anterior; AMVL, anterior mitral valve leaflet; AoV, aortic valve; LAA, left atrial appendage; P, posterior; PMVL, posterior mitral valve leaflet; S, septal.

Bidirectional flow at the interatrial transseptal puncture site was noted at the time of retracting the catheter into the right atrium. However, the iatrogenic atrial septal defect was not closed at that point in the procedure in order to minimize the risk for the septal closure device to interact with the delivery catheter and clip apparatus during the maneuvers. Furthermore, in some cases, alleviation of TR may adequately improve the right atrial pressures to resolve the bidirectional shunt. Conversely, earlier closure of the shunt may be necessitated by intraprocedural desaturation due to right-to-left shunting. For this patient with long-standing pulmonary hypertension and right ventricular dysfunction, bidirectional shunting persisted despite the reduction in TR (Figure 10, Video 12). Her iatrogenic atrial septal defect was successfully closed using a 20-mm Cardioform Septal Occluder (W.L. Gore & Associates, Flagstaff, AZ) with no residual shunt seen on color Doppler (Figure 10).

Figure 10

(A) Bidirectional shunting is noted at the interatrial site of transseptal puncture in this patient with long-standing pulmonary hypertension and known right ventricular dysfunction. A Cardioform Septal Occluder successfully closed the iatrogenic atrial septal defect, seen here in (B) three-dimensional view from the left atrial aspect (white arrowhead) and (C) in basal short-axis view with and without color Doppler. AoV, Aortic valve; LA, left atrium; RA, right atrium.

Discussion

TR is an independent predictor of morbidity and mortality after successful surgical or percutaneous repair of concomitant mitral valve disease.1, 2, 3, 5, 6, 7 The majority of TR is functional in etiology and secondary to annular dilatation and malcoaptation. Therefore, tricuspid annuloplasty ring is the most common surgical repair for TR at the time of left-sided surgery. Isolated tricuspid valve surgery for recurrent or persistent TR carries high operative risk with uncertain benefit.

A number of transcatheter techniques for treatment of functional TR are under development, most by correcting malcoaptation or annular dilatation. Several challenges are unique to the tricuspid valve and require particular consideration in the design of transcatheter systems, among them the large size of the tricuspid annulus, the angulation of the valve from the inferior and superior vena cava access points, the thin right ventricular free wall, the abundant trabeculation and subchordal apparatus, and the presence of any right-sided leads or catheters. The right atrium needs to be of adequate size to accommodate the transcatheter devices and maneuvers. Annuloplasty devices must take caution to avoid the adjacent right coronary artery. Adequate leaflet coaptation for edge-to-edge techniques may require a combination of preprocedural diuresis and intraprocedural maneuvers, such as a gentle constant precordial pressure to maximize leaflet contact.

The tricuspid valve also poses new imaging challenges in its large nonplanar annulus, thin leaflets, and the anatomic variability of its leaflets for intervention. Nonstandard echocardiographic windows may be necessary to adequately visualize the valve structure. Sweeps across the valve while adjusting the probe depth or rotation can help demonstrate leaflet relationships, with the coronary sinus as a commonly used marker for the posterior leaflet. For the edge-to-edge technique described above, the regurgitant jet location and subsequent leaflet grasp were viewed from multiple imaging planes, most important the modified basal short-axis tricuspid inflow view (ME 60°–90°), the four-chamber “grasping” view of the leaflets in profile (ME 0°–20° or 160°–180°), and the short-axis (transgastric 30°) and three-dimensional en face views.

Quantification of right ventricular size and function and the presence and severity of pulmonary hypertension is critical for patient selection, as is standardized quantitative grading of TR to assess and compare postprocedural results.15, 16 As demonstrated in this case and in prior case series, the quantitative reduction in TR may be relatively modest (one- to two-grade reduction, often with residual moderate TR) but can nevertheless result in significant clinical improvement. The durability of these recent results is unknown and warrants further investigation.

Conclusion

We report a case of successful dual-valve transcatheter repair using the edge-to-edge technique in a patient with symptomatic biventricular heart failure with mixed mitral and tricuspid valve regurgitation. A two-grade reduction was achieved in both MR and TR, with evidence of immediate hemodynamic and symptomatic improvement. This case demonstrates the safe and successful application of the edge-to-edge technique in transcatheter repair of the tricuspid valve. Further study is needed to inform patient selection, optimize technique, and assess long-term outcomes.