The Food and Drug Administration is alerting health care providers about the potential for clip lock malfunctions with Abbott’s MitraClip’s delivery system.
“These events appear to occur in approximately 1.3% of MitraClip procedures and have been observed with all device models,” the FDA says inon its website.
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In its own “” to providers, Abbott reports a recent increase in reports of the clips failing to “establish final arm angle (EFAA)” and of “clip opening while locked (COWL)” events.
During device preparation and prior to clip deployment, the operator intentionally attempts to open a locked clip to verify that the locking mechanism is engaged.
COWL describes when the clip arm angle increases postdeployment. “In these cases, users observe a slippage in the lock, resulting in an arm angle greater than 10 degrees from the angle observed at deployment,” which can be identified through fluoroscopy, Abbott says.
From February 2021 to January 2022, the EFAA failure rate was 0.51% and COWL rate 0.28%, increasing to 0.80% and 0.50%, respectively, from February 2022 to July 2022, according to the company.
Despite the increase in reports, the acute procedural success rate remains consistent with historical data, according to Abbott. “Further, EFAA failure or COWL most often results in no adverse patient outcomes. COWL may lead to less MR reduction, which is often treated with the use of one or more additional clips.”
Abbott says there is also a “low incidence” of required additional interventions. No immediate open surgical conversions have occurred as a result of EFAA/COWL events, whereas 0.53% of such events have resulted in nonurgent surgical conversions.
“In any case where significant residual MR is observed after clip deployment, a second clip should be considered and implanted in accordance with the IFU [instructions for use],” it advises.
Abbott says that a “change in the material properties of one of the clip locking components” has been identified as a contributing cause of EFAA/COWL events. It is working on producing new lots with updated manufacturing processing and raw material to mitigate the risk.
Certain use conditions can also contribute to EFAA/COWL events, and are referenced in the IFU, Appendix A, it notes.
The FDA is working with Abbott and recommends that health care providers do the following:
- Review the recall notice from Abbott for all MitraClip Clip Delivery Systems.
- Be aware of the potential for clip lock malfunctions before or after deployment with this device.
- Read and carefully follow the instructions for use and the recommendations provided in the recall notice to help minimize the chance of the clip failing to lock. These include recommendations about procedural steps for implant positioning, locking sequences, establishing clip arm angle, preparation for clip release, and avoiding excessive force and manipulation when unlocking the clip during device preparation and during the procedure.
Health care professionals can also report adverse reactions or quality problems they experience using these devices to the FDA’sprogram.