HeartMate II left ventricular assist device (above) associated with adverse events. Image Source: Thoratec Corporation

Thoratec has warned that its HeartMate II blood pump may fail due to a defective lead that connects the heart pump with the system controller. At least 27 people have required surgery to replace the mechanical heart, and five deaths have been linked to the HeartMate lead problems.

The lead has been found to wear or fatigue over time, potentially interrupting pump function, according to the Pleasanton, Calif.-based company. The warning applies to HeartMate II Left Ventricular Assist Systems (HM II LVAS) with catalogue numbers 1355 to 102139, which can be found on the package’s label..

According to a notice issued on Oct. 24, Thoratec estimated that the probability a patient will require a replacement of their heart pump due to a damaged percutaneous lead is approximately 1.3 percent at 12 months, 6.5 percent at 24 months and 11.4 percent at 36 months.

These reports occurred over five years of clinical experience with 1,972 implants, the FDA said. All patients who have undergone a replacement of the HeartMate II pump survived the operation and were alive at least 30 days postoperatively. In five cases, pump replacement was not feasible and the patients expired.

The affected systems were distributed to 153 hospitals and distributors throughout the U.S., Europe, Canada and other countries.