Degenerative (or primary), which is a mechanical problem with the valve itself, and Functional (or secondary), which typically results from a problem with the heart that hinders the otherwise normal mitral valve from operating properly. An example of functional MR might be an enlarged heart that keeps the mitral leaflets from meeting all the way.
Rodriguez said MitraClip, a product of Abbott Vascular, received FDA approval in late October 2013 for patients with degenerative MR at prohibitive risk for mitral valve surgery. The COAPT trial is studying the efficacy of the device to impact the progression of heart failure in high-risk patients with functional MR. “Saint Thomas is the only site in Tennessee that has the technology at this point,” Rodriguez said. “With the trial, we are enrolling patients right now.”After patients matching inclusion criteria are selected and appropriately screened, they are randomized to receive either the MitraClip or maximal medical management. Currently, medication therapy treats symptoms but does not halt disease progression. In those receiving the clip, Stankewicz explained, “A small tube is inserted near the groin and goes up through the circulation to the heart, crossing the interatrial septum.” The placement device, he continued, is inserted through the tube, through the heart, and directed down towards the mitral valve. With the heart still beating, the moving leaflets have to be captured and aligned. “Once we’re able to grab both leaflets and ensure we’re in the correct spot, then the clip is deployed and catches.” Stankewicz added, the placement device is then removed from the catheter and the small incision above the femoral vein is closed.Although the ideal in younger or healthier patients would be to open the chest and repair or replace the valve, which has been proven to offer a durable result over the years, a significant number of patients are deemed too unstable to survive the operation or to do so with a reasonable quality of life. “Anytime you open the heart, you have to go on the bypass machine,” Rodriguez pointed out. “It’s a big stress to go on bypass,” Stankewicz agreed, adding the risk of stroke and clot is higher with traditional surgery than with MitraClip. The first patient to receive the MitraClip has done extremely well to date. “As soon as she woke up, she said she felt better,” noted Stankewicz. “The evening of the procedure, she was sitting up in her chair. The next day, she was walking around and basically wanting to go home.” The patient went from extreme fatigue to cooking a large Thanksgiving dinner for her family just a few days after leaving the hospital.Although still an investigational procedure, outcomes data does exist from an earlier U.S. trial, EVEREST, which was conducted in association with degenerative MR prior to FDA approval. “All the patients had severe mitral regurgitation. After their first clip, 64 percent of them had less than 2+ mitral regurgitation,” said Stankewicz. He added that number rises to 84 percent when including patients who ultimately had additional clips or procedures. At 2+ MR, patients are considered to have mild regurgitation and are most likely asymptomatic. “It was durable at 36 months and significantly improved quality of life,” he added of the three-year follow-up. Rodriguez pointed out that patients who receive the MitraClip are not precluded from having open-heart surgery at a later date if their risk profile improves and the need still exists. He noted the MitraClip procedure is a complement to Saint Thomas Heart’s transcatheter aortic valve replacement (TAVR) program for patients with severe aortic stenosis. MitraClip is the only valve repair alternative for many of these patients. Stankewicz concluded. “To be able to offer a new technology to patients who had no options before is very exciting.”