Curr Cardiol Rep (2014) 16:443 DOI 10.1007/s11886-013-0443-6


Percutaneous Mitral Valve Repair Amelia Young & Ted Feldman

Published online: 27 November 2013 # Springer Science+Business Media New York 2013

Keywords Mitral regurgitation . Percutaneous mitral valve repair . Edge-to-edge leaflet repair system . MitraClip

invariably result. MR due to flail leaflet almost invariably required surgery at 10 years [3]. Regardless of the etiology of MR, functional or degenerative, traditional medical therapy relieves symptoms to a certain extent but does not reverse the underlying pathology. Surgical repair or replacement of the valve is currently the mainstay for treatment in the presence of significant symptoms, and is recommended for dilated left ventricle, new development of atrial fibrillation, or pulmonary hypertension [4]. Many patients are high risk for surgery and do not have a surgical option. Based on surgical principles several less invasive, percutaneous therapies for the treatment of MR were developed for patients who otherwise would not have an option for any mechanical treatment. A better understanding of the complex interplay of the mitral valve leaflets, the other components of the mitral apparatus, and the left ventricle has led to development of various percutaneous mitral valve therapies such as the edge-to-edge leaflet repair system, indirect annuloplasty by way of the coronary sinus, and direct annuloplasty.


Leaflet Repair

Severe mitral regurgitation (MR) carries an annual mortality rate of 5 % [1, 2]. Symptoms may develop insidiously over a number of years because the left ventricle accommodates the volume overload of MR and progressively dilates and hypertrophies to augment forward cardiac flow. When the left ventricle can no longer compensate, pulmonary edema and congestive heart failure

In the 1990s, Alfieri pioneered a novel surgical mitral leaflet edge-to-edge technique referred to as the “Alfieri stitch”, which involved suturing the opposing middle leaflet scallops together, thereby creating a double orifice [5]. In approximately 80 % of cases reported, Alfieri performed this procedure in combination with mitral annuloplasty. Alfieri’s group reported outcomes in a smaller, selected group with isolated surgical edge-to-edge repair without annuloplasty. After 12 years follow-up these patients had results comparable to that of conventional repair techniques with annuloplasty [6]. The MitraClip device (Abbott, Abbott Park, IL) is based on this surgical edge-to-edge repair and is a novel transcatheter device for mitral valve repair (Fig. 1). Of the various

Abstract Nonsurgical treatment of clinically important mitral regurgitation (MR) has evolved tremendously over the past decade. Recent studies of percutaneous mitral valve repair procedures have shown that less invasive procedures are safe and can be effective in selected patients. MitraClip has been studied most extensively. The MitraClip is attached to the middle scallop of the mitral leaflets by a transseptaltransvascular approach. The device approximates the leaflets in an edge-to-edge percutaneous repair technique that diminishes MR, improves functional status, and improves left ventricular remodeling. The subgroup that has the most benefit includes patients with older age, poorer left ventricular function, and functional MR and is considered high risk for surgical valve replacement. Other novel percutaneous mitral valve therapies under investigation include indirect and direct annuloplasty, and ventricular remodeling devices.

This article is part of the Topical Collection on Interventional Cardiology A. Young : T. Feldman (*) Cardiology Division-Walgreen Building 3rd Floor, Evanston Hospital, 2650 Ridge Ave., Evanston, IL 60201, USA e-mail: [email protected]

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Fig. 1 Fluoroscopic images of the Evalve MitraClip procedure. Panel A shows the open clip above the mitral valve. In panel B the clip has been passed across the mitral leaflets into the left ventricular cavity. In panel C the clip has been pulled back to grasp the mitral leaflets, and then closed. Panel D shows the clip after release from the delivery system. (With permission from: Goldberg SL, Feldman T: Percutaneous mitral valve interventions: overview of new approaches. Curr Cardiol Rep. 2010 Sep;12(5):404–12) [46]

percutaneous mitral valve therapies, the MitraClip system has the largest clinical experience and has been implanted in over 9000 patients worldwide. The MitraClip system permanently approximates the leaflets, thereby forming a double orifice. The procedure is performed in the beating heart under general anesthesia with fluoroscopic and transesophageal echocardiographic guidance through a transfemoral venous approach. The MitraClip system consists of three main components: MitraClip device, delivery catheter, and steerable guide. The delivery catheter is a 10French system with the MitraClip affixed to its distal end. The delivery catheter and clip are passed through the steerable guide. The steerable catheter is used for access to the left atrium through a transseptal technique and is 24 F at the skin and 22 F at the level of the atrial septum. The implantable MitraClip is a 4 mm wide cobaltchromium alloy covered by polypropylene fabric that promotes tissue growth and bridge formation. The arms of the MitraClip are 8 mm long and extend, grasp, and coapt the two leaflets. The MitraClip is navigated through the left atrium to a point above the origin of the MR jet using a combination of TEE and fluoroscopic guidance. It is critical that the trajectory of the device is oriented perpendicular to the line of leaflet coaptation. The clip is opened to 180° just above and oriented perpendicular to the line of leaflet coaptation, and then passed across the orifice and pulled back to grasp the leaflet edges. An assessment of leaflet insertion is made, and then the clip is closed. If the position of the clip is not ideal or reduction of MR is insufficient by TEE, the operator may release and adjust the position of the clip to optimize MR reduction under

echocardiographic guidance. A second or even third clip may be placed if the degree of MR reduction from first device is insufficient. The initial phase I study of the MitraClip (EVEREST I) established the safety of the device and demonstrated reduction in severity of MR and improved clinical outcomes that were sustained at 6 months [7, 8]. EVEREST II was a randomized comparison of the MitraClip device and conventional surgical mitral valve repair or replacement in patients considered to be good surgical candidates (Table 1) [9••]. Two hundred seventy nine patients with moderate to severe (grade 3+ or 4+) MR were randomly assigned in a 2:1 ratio to undergo either a percutaneous repair (n =184) or surgery (n =95). The inclusion criteria were taken directly from the AHA-ACC valve therapy guidelines. Symptomatic patients were required to have left ventricular ejection fraction (LVEF) greater than 25 % and a left ventricular end-systolic diameter (LVESD) of 55 mm or less in addition to 3-4+ MR. Asymptomatic patients were required to have at least one of the following: LVEF 25 to 60 %, LVESD 40-55 mm, new onset atrial fibrillation, or pulmonary hypertension. Exclusion criteria included LVEF less than 25 %, LVESD greater than 55 mm, or mitral orifice area less than 4 cm2. Specific anatomic criteria were required. Among patients with a degenerative mitral valve, a flail segment≥15 mm or a flail gap≥ 10 mm were excluded. In the case of functional MR, a coaptation depth>11 mm or vertical coaptation length< 2 mm were excluded. The majority of the patients had degenerative mitral valve as the etiology of MR. The final

Curr Cardiol Rep (2014) 16:443

conclusions of the EVEREST II trial were that although percutaneous repair was less effective at reducing mitral regurgitation than conventional surgery; the procedure was associated with superior safety and similar improvements in clinical outcomes. The details of the trial are important for understanding and interpreting the main conclusions. The primary efficacy endpoint was a composite of freedom from death, from surgery for mitral valve dysfunction, and reduction in severity of MR. Overall, the rate of the primary efficacy endpoint in the percutaneous-repair group was 55 % versus 73 % in the surgery group (p =0.007). The rates of death (6 %) in the two study groups were not statistically different at 12 months. Rates of post-procedure 3+ or 4+ MR were not significantly different between the percutaneous repair group (21 %) and surgery group (20 %), whereas the rate of surgery for mitral valve dysfunction was 20 % in the percutaneous-repair group and 2 % in the surgery group (p

Percutaneous mitral valve repair.

Nonsurgical treatment of clinically important mitral regurgitation (MR) has evolved tremendously over the past decade. Recent studies of percutaneous ...
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