A 91-year-old man with a history of coronary artery disease and prior bypass surgery (> 10 years ago) had been very active, going for walks and even doing his own yard work. Over a period of several months, however, he developed progressive shortness of breath, lower-extremity edema, and fatigue. His cardiologist discovered that he had heart failure due to severe mitral regurgitation with associated atrial fibrillation and pulmonary hypertension. Because of the patient’s advanced age, prior bypass surgery, and kidney disease, his cardiologist determined that his risk of complications with conventional open-heart surgery would be too high to consider pursuing that option.
Are there any alternatives to conventional surgery for this high-risk patient?
Answer: Yes, new minimally invasive, percutaneous catheter-based approaches are now available for mitral valve repair.
Video 1. 3D transesophageal echocardiogram (TEE) image of the mitral valve from the left atrium, with a flail segment of the posterior leaflet that results in severe mitral valve regurgitation.
Video 2. 3D TEE image of the first MitraClip being positioned and aligned above the flail segment of the mitral valve, before attempted grasping of leaflets. The clip would then be advanced across the mitral valve into the left atrium and then retracted gently to grasp the anterior (top) and posterior (bottom) leaflets in the location of the mitral regurgitation.
Video 3. 3D TEE image of the second MitraClip grasping both leaflets (the first clip is already implanted to left of the second clip), before implanting the clip. Grasping the leaflets before implantation/deployment allows for the assessment of the reduction in mitral regurgitation. The double orifice of the mitral valve is now seen.
The patient was referred to Duke Medicine’s Andrew Wang, MD, an interventional cardiologist, for a MitraClip procedure, a novel, minimally invasive, percutaneous catheter-based approach to mitral valve repair. The MitraClip device received Food and Drug Administration approval in 2013 for use in patients with degenerative mitral regurgitation who have a high risk of complications with conventional surgery. It involves placing one to two 10-mm, cobalt-chromium clip implants on the leaflets to reduce regurgitation.
“He's typical of the type of patient for whom the MitraClip procedure is indicated—an older person with other medical problems who’s often had a previous heart surgery. This is a good option in such cases,” Dr. Wang commented.
The patient underwent the mitral valve repair in May 2014. “If he had not undergone MitraClip, there is a high chance he wouldn't have survived another few months,” Dr. Wang said.
Duke University was one of the sites involved in the pivotal Endovascular Valve Edge-to-Edge Repair Study (EVEREST) that compared the MitraClip procedure head-to-head with conventional surgery. Patients in the study who underwent the MitraClip procedure had improvement in symptoms similar to conventional surgery and fewer complications, although they had more residual mitral regurgitation. A subsequent observational study enrolling high-risk patients showed a very low risk (< 5%) of procedural death, stroke, bleeding, or other major complications, and the majority of patients had improvement in their symptoms.
The MitraClip procedure is performed under general anesthesia using transesophageal echocardiography to allow 3-dimensional (3D) visualization of the left atrium and mitral valve, Dr. Wang explained (Video 1). The MitraClip device is inserted and advanced through the femoral vein and accesses the left side of the heart through a transeptal puncture from the right atrium (Video 2). The device has several control knobs that are manipulated to steer the clip toward the part of the valve that is to be repaired. The mitral valve leaflets are then grabbed by the device, and the clips are applied (Video 3). “I tell patients it’s like two curtains opening and closing across a window,” Dr. Wang said. “There's a gap between the curtains in the center part because one of the curtains is too floppy. What we’re trying to do is steer the device to put a small clothes pin or a clip on that part where there's the separation between the two curtains. This essentially creates a double orifice mitral valve.”
Approximately 3 months after the procedure, endothelial cells grow over the clips, Dr. Wang said. Clip detachment is rare (< 5% of patients).
Two clips were implanted during the patient's procedure, and his mitral regurgitation was reduced to a mild degree. He returned for a follow-up visit 1 month later. “By subsequent echocardiogram, his pulmonary hypertension resolved, and he was back in normal rhythm at follow-up, so a lot of the abnormal complications of the regurgitation were better,” Dr. Wang said. The patient also reported returning to his previous activity level and experiencing a reduction in his symptoms.
The procedure has been performed approximately 100 times at Duke Medicine and more than 15,000 times worldwide.