FDA warns of dangerous errors made during implantation of Abbott's MitraClip

MitraClip cardiac device--Courtesy of Abbott

Abbott ($ABT) said it will retrain implanters of its transcatheter MitraClip device for mitral valve repair following reports of procedures in which the implant could not be detached from the delivery device. All 9 reported cases resulted in surgical interventions, and one ended in postoperative death due to severe comorbidities.

And the FDA publicized the company's Feb. 4 field notice, a sign that the agency believes the issue is critical to patient safety. There are 3,543 MitraClips on the market, the FDA said, including 2,246 outside the U.S.

The agency said that the adverse event occurred due to operator error, writing "Abbott's investigation determined that the delivery system's 'arm positioner' was not returned to the required neutral position by the operator during the deployment sequence, subsequently preventing the Clip from detaching."

Abbott's field notice contains the text of its revised instructions for use, and asks the participant to sign a form and return it to company following the completion of training with an Abbott representative.

This incident highlights the importance of device usability, operator experience and operator training, for many other safety scares in the device world are unrelated to a technical defect with the device itself.

The MitraClip is the only FDA-approved transcatheter mitral valve repair device. Similar implants from Cardiac Dimensions, Neochord and Valtech have received CE marks.

Abbott said that sales of MitraClip increased by double digits during Q4 2015. It previously revealed that device earns about $250 million per year. The company obtained the device when it acquired Evalve for up to $410 in 2009, and achieved FDA-approved to treat the degenerative form of mitral regurgitation in 2013.

Now, Abbott is conducting several clinical trials to earn an expanded indication from the treat functional MR as well. The lead FDA trial needs 80 more patients to meet its goal of 430 patients, reports TCTMD.

As such, doubts about the MitraClip have been on the efficacy side, not the safety side. The repair technique that it facilitates has been "largely abandoned" as an isolated surgical procedure (meaning it would be performed via open heart surgery, unlike in the case of the minimally invasive MitraClip) TCTMD says.

During its FDA panel review in 2013, the experts recommended approval on the basis of its risk/reward profile, but voted 5-4 against the devices' effectiveness. The panel also voted 8-0 that the device is safe.

Several transcatheter mitral valve replacement (as opposed to repair) devices are being developed, with the help of funding from acquisitions worth more than $1 billion from bigwigs Abbott, Edwards ($EW) and Medtronic ($MDT). Although they are efficacious, the development process is going slowly due to severe engineering problems and challenges regarding patient safety.

In spite of the recent field notice, MitraClip faces the "opposite" issue, Dr. Danny Dvir of St. Paul's Hospital in Vancouver said.

He told TCTMD that the device continues to sell fairly well (especially in Europe) despite questions about its efficacy due to its strong safety profile. The limited (or non-existent in the case of the U.S.) number of direct competitors helps as well.

- read the FDA's warning
- here's Abbott's field notice letter to doctors
- here's more from TCTMD | and more