Percutaneous clip reduces mitral regurgitation in FMR patients
MitraClip may prove effective for patients with FMR. Source: Evalve  
A percutaneous mitral repair using the MitraClip device successfully reduced mitral regurgitation (MR) in patients suffering from functional mitral regurgitation (FMR), according to a study presented on Tuesday at the American College of Cardiology (ACC) meeting in Chicago.
People suffering from FMR are subject to heart failure as the heart must work harder to make up for blood leaking backward through the mitral valve.

“Of the 50,000 patients in the United States who develop significant MR each year, up to 60 percent have FMR,” James Hermiller, MD, director of the interventional fellowship at St. Vincent Heart Center of Indiana in Indianapolis, told Cardiovascular Business News

Hermiller presented the results from the ongoing EVEREST (Endovascular Valve Edge-to-Edge REpair STudy) trial.
“Demonstrating that the left ventricular enlargement is actually reversing itself is important objective evidence that the heart is responding favorably,” Hermiller said.

The MitraClip, mounted on the end of a catheter, is threaded through the femoral vein into the right atrium. A needle puncture in the wall separating the upper chambers of the heart enables the catheter to pass into the left atrium, where the clip is opened up like a clothespin that is then passed through the mitral valve into the left ventricle. When the heart contracts, the flaps of the mitral valve are grasped by the clip, which is then closed, securing the edges of the valve flaps together at their centers, according to Hermiller.

The researchers focused on 23 patients treated at 15 medical centers either during the EVEREST I study or during the roll-in phase of the ongoing EVEREST II study, which is comparing MitraClip therapy to open-chest surgery. All of the patients in the new analysis had FMR, which results not from a defect in the valve leaflets but from enlargement of the valve opening as a result of heart attack or heart failure.

The larger ongoing EVEREST II trial has 59 roll in patients, 129 randomized to clip and 61 randomized to surgery (the randomized study is a little over 60 percent enrolled and progressing).

Before the procedure, Hermiller said that all patients had moderately severe or severe MR, and 83 percent of patients had heart failure ranked as New York Heart Association functional class III or IV, which is characterized by lung congestion, shortness of breath, fatigue, swelling of the legs, and difficulty with light-to-moderate physical activity. After the procedure, MR was mild to modest in 19 of 22 patients (83 percent) treated with the MitraClip, the researchers reported.

“Among the four patients that were considered unsuccessful attempts, in three of the four patients, the clip just didn’t work. They were not considered procedural successes and went on to have their mitral valves repaired,” Hermiller explained.

The final patient needed to have a transceptal complication and needed to have the valve repaired, and the clip was not attempted at that point, according to Hermiller. 

After one year, 12 patients had completed follow-up and had matched data from both baseline and follow-up. The investigators said that 10 of the 12 patients continued to have only mild to modest MR and nine of 12 continued to enjoy an improvement in symptoms and daily function of at least one NYHA class. In addition, heart size was significantly smaller, according to researchers.

“This is a small study, but it demonstrates a proof of principle that the MitraClip can reduce MR and improve heart function in patients with FMR,” Hermiller said. “These findings are promising, but clearly we need a lot more data.”

“Just as important as a proof of concept is the follow-up ultrasound in these patients, which showed that their hearts were remodeling in a positive way. Their left ventricle chamber decreased in size. So we could see that enlargement that occurs with MR was actually reversing over time,” Hermiller noted.

The ongoing EVEREST II is examining the longer-term effects of the MitraClip.

“If it’s shown to be effective, compared to surgery, and we certainly need to have the EVEREST II data to say that, it will be considered highly cost-effective because these patients will go home the next day after having had a percutaneous procedure with a band-aid on their leg. The length of stay, and the patients can return to their normal routine within a week,” Hermiller explained.   

The MitraClip is manufactured by Evalve of Redwood City, Calif., which funded the study.