The U.S. Food and Drug Administration (FDA) has issued a safety communication warning of serious adverse events associated with two implantable left ventricular assist devices. The two heart systems, which happen to be the only implantable devices of their kind approved by the FDA, are the HeartMate II Left Ventricular Assist System, manufactured by Thoratec Corporation, and the HeartWare Ventricular Assist System, manufactured by HeartWare, Inc.
According to the FDA communication, left ventricular assist devices help the left ventricle of the heart pump blood throughout the body in patients with advanced heart failure. The devices are comprised of three parts: a blood pump; a power pack; and a controller. The blood pump is surgically attached to the patient’s left ventricle and aorta, while the power pack and controller are linked to the pump and carried outside of the body. The HeartMate II and HeartWare assist systems are approved for patients at risk of death from non-reversible left ventricular heart failure. The devices are intended to support circulation while patients wait for a heart transplant. They may also be used as an indefinite solution in patients not awaiting transplants.
The FDA has listed serious adverse events associated with one or the other device, as well as some associated with both. For Thoratec’s HeartMate II, the FDA cites reports “indicating an increase in the rate of pump thrombosis events” (situations in which there is blood clotting in the pump portion of the device). The reports suggest that patients with the HeartMate II may experience pump thrombosis earlier than was observed in trials for the device. The FDA notes that pump thrombosis is a serious complication that can require revision surgery or result in death.
The adverse event reports concerning the HeartWare system have to do with complications in long-term implants (i.e., those implanted in patients not awaiting transplants). Investigators found a 29 percent incidence of stroke in patients who carried a HeartWare implant for more than two years, compared with a 12 percent incidence in patients with a HeartMate II implant.
Adverse event reports indicated that both the HeartMate II and HeartWare assistance systems may result in bleeding complications, though the FDA is not currently aware of the exact cause.
The agency recommends that practitioners carefully evaluate the risk–benefit ratio in candidates for these devices, and consider the apparent risk of bleeding when prescribing additional treatment (such as anticoagulants). Patients are encouraged to consult their doctors about the risks and benefits of implanting one of these devices.
Medical device manufacturers have a duty to ensure the safety of consumers. If you or someone you know was injured by a defective medical device, contact the product liability lawyers at Lopez McHugh for a free legal consultation.