Herrmann v1.qxp 16/7/08 10:10 Page 39
Interventional Cardiology
Percutaneous Repair of Mitral Regurgitation with the MitraClip
®
System
a report by
Howard C Herrmann, MD
Professor of Medicine, and Director, Interventional Cardiology and Cardiac Catheterization Laboratories, University of Pennsylvania Medical Center
Mitral regurgitation (MR) is most often caused by degenerative disease of The procedure is performed under general anesthesia, primarily using
the leaflets or develops functionally as a consequence of left ventricular realtime transesophageal echocardiography in a unique collaboration
disease (see Figure 1). Patients with severe MR have dyspnea on between the echocardiographer, anesthesiologist, and interventionalist.
8
exertion, fatigue, and, when associated with left ventricular dysfunction or Patient selection using echocardiography is key to the success of the
pulmonary hypertension, reduced survival.
1
Therefore, surgery to repair procedure. A minimum of three of the six American Society of
or replace the mitral valve is considered to be a class I indication in Echocardiography (ASE) criteria for moderate to severe (3+) or severe
symptomatic and asymptomatic patients with left ventricular dysfunction. (4+) MR as assessed by a core laboratory are required for study inclusion.
9
Surgery is also considered reasonable (class IIA) in patients with preserved In addition, specific leaflet dimensions and the origin of the regurgitant
left ventricular function if the likelihood of a successful repair is high.
2
jet origin are assessed. An example of a patient treated with this
technique is shown in Figure 2.
However, surgery has a number of limitations. Serious complications occur
in up to 20% of patients, and may include peri-operative myocardial Results
infarction (MI), stroke, septicemia, renal failure, respiratory failure, Approximately 400 patients have now been enrolled in North American
re-operation, and death. Up to 20% of older patients may have additional trials with the MitraClip system. The Endovascular Valve Edge-to-Edge
complications after discharge, prompting re-admission within 30 days.
3
Repair Study (EVEREST) I enrolled 55 patients in a phase I safety and
Finally, although many surgical series report a high rate of freedom from feasibility trial.
6,10
The ongoing EVEREST II trial is a pivotal randomized,
re-operation after mitral repair, results including overall survival and the prospective trial in 279 patients comparing the MitraClip device with
rate of recurrent MR are not as good. For instance, in a recent report of standard surgical repair or replacement. Patients with either degenerative
649 consecutive isolated mitral valve repairs for degenerative MR, the or functional MR are randomized 2:1 to the MitraClip or surgery, with a
freedom from re-operation at 15 years was 92%.
4
However, by 15 years primary effectiveness end-point of freedom from surgery for valve
33% of patients had died and recurrent severe MR was present in 30%.
4
dysfunction, death, or 3–4+ MR at one year. The EVEREST II trial, which is
currently over 70% enrolled, will provide important information on
The rationale for the development of percutaneous techniques to treat MR efficacy compared with surgery, and will help cardiologists decide how to
stems from a desire to reduce the morbidity and mortality of surgical repair apply this new technique in practice. An additional 78 patients were
or replacement, and to improve results. The various techniques under enrolled in a non-randomized registry for patients with a high risk for
development include devices inserted into the coronary sinus in order to surgical mortality.
remodel the adjacent posterior mitral annulus (‘indirect annuloplasty’), more
direct annuloplasty and ventricular remodeling devices, leaflet repair, and The results obtained in 104 patients, including 55 patients in the EVEREST
percutaneous mitral valve replacement.
5
The remainder of this article will I feasibility trial and 49 non-randomized ‘roll-in’ patients in the EVEREST II
focus on leaflet repair using the MitraClip
®
device (Evalve Inc., Menlo Park). trial, have been reported.
6,10,11
These patients represent the first patients
treated who have 30-day core laboratory follow-up. The mean age of
Technique
Percutaneous edge-to-edge repair with the MitraClip device
6
is based on
a similar surgical approach using suture described by Alfieri.
7
In the
Howard C Herrmann, MD, is a Professor of Medicine at the
University of Pennsylvania School of Medicine and Director of
percutaneous procedure, a 24 French guide catheter (22F in the distal
Interventional Cardiology and the Cardiac Catheterization
portion) is inserted into the left atrium from the right femoral vein with Laboratories at the Hospital of the University of Pennsylvania,
standard trans-septal techniques. The clip delivery system with the
Philadelphia. He has authored or co-authored more than 200
articles on numerous topics in interventional cardiology. His
MitraClip attached at its distal end is passed through the guide catheter
research focuses on the clinical investigation of new therapies
into the left atrium and steered through the mitral valve using knobs on for valvular and structural heart disease. He is Past President
the proximal handle. The clip itself is a polyester-covered device that can
of the Pennsylvania Chapter of the American College of
Cardiology (ACC) and serves on numerous national committees and Editorial Boards.
be opened and closed repeatedly to grasp the leaflets to create a double-
Dr Herrmann earned his AB at Harvard College and his MD at Harvard Medical School, and
orifice mitral valve by co-apting the central leaflet scallops. The tissue can completed his training at Massachusetts General Hospital.
be released and the clip repositioned as necessary to achieve adequate
E: howard.herrmann@uphs.upenn.edu
MR reduction, and a second clip can be placed if necessary.
© TOUCH BRIEFINGS 2008
39
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