MitraClip therapy: Which patients are ‘sick enough’?
February 20, 2019
Mitral valve disease is often characterized by mitral regurgitation (MR) – the leaking of blood and disruption of flow through the heart valve. The ideal treatment is valve replacement surgery. However, for some patients with severe MR the risks of anesthesia and infection are too great, and they cannot safely have heart surgery.
Since 2015, the multidisciplinary team at UT Southwestern has provided avenues of care for patients with severe MR who can’t have surgery. UTSW cardiologists were early users of MitraClip, a small, permanent device delivered without open-heart surgery, which is approved for patients with primary MR – those who have a problem with the mitral valve itself. For these patients, the MitraClip strategy has been an effective and potent treatment option.
In nearly three-fourths of patients with MR, the condition is actually a sign of a failing heart. When the heart functioning is poor, it doesn’t pump blood forward effectively, resulting in backflow and mitral regurgitation – often in the setting of a mitral valve that is otherwise relatively normal from a structural standpoint. In these patients, it is very important to optimize medications that can improve heart functioning, which then results in an improvement in MR.
"The concept of being sick but not quite sick enough for MitraClip can be tough to swallow for MR patients and their families, particularly when media pieces suggest otherwise. A patient might reasonably think, 'I have MR. My heart is failing. What do you mean I’m "too well" for this procedure?'"
Results of a national clinical trial called COAPT show that MitraClip could be effective among carefully selected patients with secondary MR. However, the pool of individuals that would potentially benefit is likely to be small. The results also were published in The New England Journal of Medicine in an article titled “Transcatheter Mitral-Valve Repair in Patients with Heart Failure.”
The concept of being sick – but not quite sick enough – for MitraClip can be tough to swallow for MR patients and their families, particularly when they see this technology promulgated in the media. A patient might reasonably think, “I have MR. My heart is failing. What do you mean I’m ‘too well’ for this procedure?” These discussions require a data-backed understanding between doctors and patients regarding who can benefit from MitraClip and how seeking treatment at a heart care center of excellence can take your care in an entirely different – and ultimately more effective – trajectory.
The research behind MR and MitraClip
Secondary MR (that is, MR not due to a structural abnormality in the valve itself but rather deriving from changes in surrounding heart muscle, often dilation of the main pumping chamber of the heart) has been a tough nut to crack. Surgical treatment is frequently not durable, and medical management has its limits. Moreover, an earlier European study of about 300 patients with moderate to severe secondary MR failed to unveil benefits from using MitraClip. Therefore, many cardiologists assumed that COAPT also would be negative, and the device might be pulled from the market. However, COAPT surprised many doctors when the study showed robust benefits in a narrower population of sick patients whose ventricles (not valves) were weak, thereby causing MR – that is, among patients with secondary MR.
Eligible patients with secondary MR at 78 hospitals in the U.S. were randomized to receive either medical optimization only or medical optimization in combination with MitraClip, and then both groups were monitored for 24 months. Researchers discovered that combining medical optimization with MitraClip resulted in better outcomes compared to medical optimization alone. The benefits were strikingly positive in the device group:
- 35.8 percent of patients were
hospitalized, compared with 67.9 percent in the control group
- 29.1 percent died from any cause
during the 24-month monitoring period, compared with 46.1 percent in the
- The rate of freedom from device-related complications was 96.6 percent after 12 months
It’s worth noting that approximately 5 percent of patients in the COAPT device group and 10 percent in the medication group went on to receive either a left ventricular assist device (LVAD) or a heart transplant. Because patients with MR can be very sick, it’s important to keep them in contact with their entire heart failure team throughout treatment and beyond.
Teamwork is key in MR treatment
At UT Southwestern, our comprehensive valve team works very closely with our heart failure specialists for patients with heart failure and MR. There are two reasons for this. First, optimizing medications for heart failure is complex; we often find that patients have been prescribed multiple medications with sub-optimal efficacy by well-meaning doctors who do not specialize in heart failure. These drugs can be expensive and can cause interactions while not improving a patient’s condition or symptoms.
Second, as discussed above, for many patients, medical management is sufficient to avoid an unnecessary procedure or surgery. Although recovery from MitraClip implantation generally is quicker and less painful than recovery from “open” valve replacement surgery, patients still must take time off work or activities, find a ride, and arrange for help at home. With medication management, patients can see dramatic results much quicker without the need for additional downtime or activity restrictions.
For patients in whom these approaches don’t work, our valve specialists work together as a team to find the best treatment option. As part of this, the interventional cardiologists at UT Southwestern meet every week with cardiothoracic surgeons and imaging specialists – meetings that involve crosstalk among specialized heart experts who, together, optimize each patient’s MR care as it relates to medication, surgery, and optimal outcomes. As with many heart care devices and procedures, we anticipate additional research will uncover more applications for MitraClip alongside medical optimization.
What research is needed to more broadly provide MitraClip?
Today’s data has shown that a narrow pool of patients currently benefits from MitraClip. However, additional research likely will uncover broader applications of the device. Specifically, we need further studies into who benefits over a longer follow-up period than 24 months (the duration of COAPT). Further research also must examine disparities in care, such as sex, race, and access.
One major point of significance that studies emphasize is the need for patients to connect with cardiovascular systems of care – health care centers that are most likely to achieve optimal outcomes based on the specialized programs available and expertise in and volume of complex cardiovascular procedures. I am passionate about this topic, and I give lectures and engage other organizations at the national level to work toward this patient-centric care model. For example, patients with MR should receive care from a medical center with a heart failure program and expertise in advanced heart failure treatment (including medication and devices). Additionally, high-volume and experienced centers such as UT Southwestern tend to have better outcomes due to the number of patients with complex needs who are referred to us for advanced care.
To reiterate, MitraClip currently is approved only for patients with primary MR (valve issues). Based on COAPT, we expect that MitraClip will soon be available as a treatment option for secondary MR (primary problem is the ventricle) in the U.S. as well. The common thread, and our “sweet spot” in MR patient care, is the perfect balance of medication optimization and knowing when to recommend a patient for a procedure or device. UT Southwestern patients have the advantage of a collaborative team of doctors who together find the best, highly individualized solution rather than shoehorning a patient’s therapy to the techniques at which an individual doctor excels.
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