The FDA today announced a Class I recall — the most serious kind — for the Medtronic (NYSE:MDT) Harmony delivery catheter system.

Medtronic designed the Harmony transcatheter pulmonary valve (TPV) system for treating a leaky native or surgically repaired right ventricular outflow tract (RVOT). It consists of a transcatheter pulmonary valve and a delivery catheter (the Harmony delivery catheter) that allows for the implantation of a replacement valve without open-heart surgery.

The FDA approved the device, described by Medtronic as a first-in-the-world, non-surgical heart valve to treat severe pulmonary valve regurgitation, in March 2021.

In total, 665 devices distributed between April 7, 2021 and Jan. 26, 2022, were affected by the recall, which was initiated on March 2, 2022. To date, there have been six reported complaints from clinical cases, one injury and zero deaths associated with the use of the devices, according to an FDA release.

Medtronic recalled the Harmony delivery catheter because of the possibility that the bond holding the capsule at the end of the delivery catheter may break during a procedure to place the TPV. A capsule bond break could cause procedure delays while the device is replaced with a new one or may require additional surgeries for the patient.

Additionally, a capsule bond break while in use during a procedure could cause serious harm to the patient, with risks including preventing blood flow and/or completely blocking (embolization or occlusion), tearing and/or splitting (perforation or dissection) or other types of damage to the patients’ blood vessels.

Customers have been instructed to remove all unused products from use and return them to Medtronic, as well as to pause new clinical cases involving the Harmony TPV system.