Catheter Management Of Mitral Regurgitation
- Article Author:
- Kristen Brown
- Article Editor:
- Michael Lim
- Updated:
- 8/31/2020 11:34:33 AM
- For CME on this topic:
- Catheter Management Of Mitral Regurgitation CME
- PubMed Link:
- Catheter Management Of Mitral Regurgitation
Introduction
Mitral regurgitation (MR) is one of the most common valvular abnormalities. Medical management, along with regular surveillance, is the recommendation for mild MR. Traditionally, the management of severe disease has involved surgical intervention. More recently, studies have proven that the transcatheter approach is falling in favor. The edge-to-edge leaflet repair device is a minimally invasive catheter-based therapy that uses a clip to bring together the tow flailing leaflets, which results in decreased or the resolution of regurgitation. This article will discuss in detail primary and secondary mitral regurgitation, non-invasive catheter management options, including indications, contraindication, procedural technique, and complications.
Anatomy and Physiology
The mitral valve (MV) apparatus is a complex anatomic structure that includes the ventricle, papillary muscles, chordae tendineae, leaflets, and the mitral annulus. Alteration to any of these can lead to the development of mitral regurgitation (MR).[1] Mitral regurgitation is when the valve does not close completely, which allows for backward blood flow leading to several different problems. The two types of MR are primary or secondary. Primary mitral regurgitation is degenerative valve disease, while secondary mitral valve regurgitation is characteristically a functional myocardial disease. MR can further classify as mild, moderate, and severe. Severe (or moderate-severe) MR is currently only recommended for catheter management. The echocardiogram is the primary tool used to assess the severity of MR. Severe MR is described as having a color flow jet that may be central and large (>6 cm or >30 percent of the left atrial area) or smaller if eccentric, encircling the left atrium. Pulmonary vein flow may show systolic blunting or systolic flow reversal, vena contracta width =0.5 cm measured in the parasternal long-axis view, a regurgitant volume of =45 mL/beat, regurgitant fraction =40 percent, and/or regurgitant orifice area =0.30 cm^2 according to the American College of Cardiology and American Heart Association.[2] Several interventions exist to treat severe MR, including surgical and non-surgical. If left untreated severe MR can lead to fatal sequelae, including heart failure.
Indications
Currently, the edge-to-edge leaflet repair device is the only recommended intervention to treat MR are limited, but there are many emerging technologies including but not limited to neo-cords, transcatheter mitral valve repair, and rings. At present, the following are the indications for this device:
- Moderate to severe primary MR (3 to 4+)
- Severely symptomatic heart failure
- Non-surgical candidate
- Repairable anatomy
- Good life expectancy
Contraindications
There are very few contraindications to catheter intervention with the edge-to-edge leaflet repair device, but the following are the contraindications for the procedures[3][4]:
- Unable to tolerate anticoagulation
- Active endocarditis of the mitral valve
- Rheumatic mitral valve disease
- Intracardiac, inferior vena cava (IVC) or femoral venous thrombus
Equipment
The edge-to-edge leaflet repair device procedure is a relatively straightforward procedure requiring only a few specific pieces of equipment listed below:
- Edge-to-edge leaflet repair device device
- Multiple catheter sizes
- Fluoroscopy machine
- Code cart
- Sterile gown
- Sterile drape
- Anesthetic
Personnel
The key personnel required to adequately and safely perform catheter-based MR treatment with the edge-to-edge leaflet repair device:
- Interventional cardiologist
- First assist (sometimes)
- Cardiology nurse
- Surgical technologist
Preparation
Before undergoing a catheter-based approach to MR, management requires a thorough assessment of the mitral valve apparatus by echocardiogram and sometimes other forms of cardiac imaging by a trained cardiovascular interventionalist. Sometimes a cardiovascular imaging specialist is used for the consult. The principal preparation for any procedure is to obtain a sterile field. As in most catheterizations, the site of sterilization is the site of catheter insertion. All personnel close to the sterile field should scrub and fully gowned. Clean and drape the area before beginning the procedure.[5]
Technique
The edge-to-edge leaflet repair device
The surgeon performs the transcatheter mitral valve repair with the edge-to-edge leaflet repair device in a laboratory specialized for cardiac catheterization. It uses a mix of fluoroscopic and transesophageal echocardiographic (TEE) guidance to image the heart before, during, and after the procedure. The patient will be under general anesthesia for ease and comfort, and to reduce movement during the procedure. The procedure begins with gaining access. The femoral vein is the preferred area of entry. A transseptal puncture is performed to cross the interatrial septum into the left atrium (LA). The edge-to-edge leaflet repair device catheter, which is manipulable within the vasculature, is then advanced into the LA. Echocardiographic guidance instrumentation is useful to position the catheter device in the correct place. The edge-to-edge leaflet repair device is then pulled back on with the clip limbs open to attach to the leaflets at the site of insufficiency. The limbs are then closed, and then a repeat Doppler echocardiography is performed to evaluate the results of the treated MR. If the MR has not undergone adequate reduction to the surgeon's satisfaction, then the device can be repositioned [2]. Once the clip positioning is satisfactory, catheter removal from the access site follows, and closure ensues with pressure. The patient is then monitored for 4 to 6 hours post-op to check for any complications.
Complications
The edge-to-edge leaflet repair device has many possible complications to include but not be limited to the following:
- Hemorrhage
- Aneurysm (or pseudo-aneurysm)
- Arrhythmias
- Thromboembolism
- Mitral stenosis
- Severe ASD requiring intervention
- Cardiac perforation
- Chordal entanglement/rupture
- Edge-to-edge leaflet repair device thrombosis
- Renal insufficiency or failure
Clinical Significance
Catheter management of mitral regurgitations is a relatively recent innovation. At the risk of an understatement, it is a considerable advancement in the world of cardiology. It allows for those with severe MR who are nonsurgical candidates to now have an option for mitral valve correction. Recently studies have shown catheter management to be superior to surgical intervention in some circumstances.[1]
Enhancing Healthcare Team Outcomes
Catheter management of mitral valve regurgitation is a serious procedure and can carry some potentially serious complications. Fortunately, most complications are rare, but the procedure should be taken seriously and performed by a highly trained cardiovascular interventionalist [level 1]. In addition to a highly trained physician, it is important to have a team approach when assessing these patients. Before the intervention, the following should take place:
- Explanation of the risks and benefits of catheter management of mitral valve regurgitation as pertains to the specific intervention
- Evaluation by the pulmonary and cardiologist to optimize lung and heart function
- Obtain imaging such as an echocardiogram to assess the function and structure of the heart before planning the procedure
- Consult by a cardiovascular imaging specialist or structuralist
- Pharmaceutical consultation for post-op pain management, antiemetics and use of blood thinners
- Consult by the anesthesiologist to ensure that the patient is fit for anesthesia
- Specialty trained cardiology nurse to assist with the pre-operative, operative, and post-operative monitoring and education of the patient and coordination of follow-up care with the team
An interprofessional team approach will lead to the best outcomes. [Level 5]
(Click Image to Enlarge)
MitraClip to manage MR
Image courtesy Bhimji MD