HeartMate II, HeartWare LVAD Devices Linked to Reports of Serious Problems , FDA Warns

Federal health regulators are warning about reports of problems associated with heart implants known as Left Ventricular Assist Devices (LVADs), indicating that a high rates of bleeds, blood clot complications, strokes and other injuries have been linked to the HeartMate II and HeartWare devices. 

In a safety communication issued on August 5, the FDA warned about serious adverse events linked the LVADs.

The agency indicated that the HeartMate II Left Ventricular Assist Device manufactured by Thoratec has had a high rate of blood clot problems interfering with the pump, known as pump thrombosis. The Heartware Ventricular Assist System HVAD manufactured by HeartWare, Inc. was linked to a large number of strokes, according to the FDA. In addition, both devices were associated with adverse events involving bleeding complications, which the agency indicates that it is still investigating.

“The cause of bleeding complications is not fully understood, but is likely due to many different factors,” the FDA warning states. “One possible factor may be modification to blood thinning (anticoagulation) therapy in an attempt to lower the risks of pump thrombosis and embolic stroke.

Thoratec HeartMate II Problems

The Thoratec HeartMate II is a coronary implant given to patients whose hearts are too weak to efficiently pump blood. Former Vice President Dick Cheney is perhaps the most famous recipient, but they have been widely used among individuals with advanced heart disease who are waiting for a heart transplant or are too weak to undergo such a procedure.

According to the FDA warning, recipients of the HeartMate II are suffering from pump thrombosis events at a rate much higher than was indicated during the device’s clinical trials. Some analysts indicate that the HeartMate II pump thrombosis rate may be as high as 8.4% after just three months, and 6% after being implanted for only six months. The FDA warns that pump thrombosis can require repeat surgery, LVAD replacement, and can lead to death.

In November 2013, researchers from the Cleveland Clinic identified an increase in the rate of blood clot-related problems with the Thoratec HeartMate II since March 2011.

After examining data from three different hospitals, they found that over the past few years there has been an increase in the rate of clot formation during the months after the HeartMate II was implanted, confirming what doctors at the hospital suspected based on their own experiences.

Researchers suggested there had been some unreported design change which may have led to the increased blood clot problems.

Thoratec has denied that any changes were made to the device and previously suggested that the small size of the November 2013 study does not accurately portray the device’s performance.

In January 2014, a Thoratec HeartMate II class action lawsuit was filed by investors who say the company withheld important information about the safety and efficacy of the device, which has caused the stock price to decline.

A number of individuals nationwide also pursuing potential Thoratec HeartMate lawsuits against the manufacturer, claiming that the suffered blood clots or other complications after receiving the artificial heart pump.

Heartware HVAD Problems

The HeartWare VAD, also known as the HVAD, is used as a bridge device on patients suffering from advanced heart failure while they await cardiac transplantation. It is used during emergency medical flights on airplanes and helicopters, as well as in hospitals, to keep patients alive until a heart transplant can be performed.

The FDA warns that a recent clinical trial designed to evaluate the HeartWare HVAD safety profile indicated that 28.7% of HeartWare HVAD patients had suffered one or more strokes over the last two years. That compares to just 12.1% of patients implanted with the HeartMate II.

In December 2013, a HeartWare VAD recall was issued because the driveline connector locking mechanism on the device may fail to engage in some units. As a result, the device could fail and stop pumping, leading to serious injury and death.

Over the last few years, HeartWare has also received at numerous complaints about the controller for the HVAD, according to information contained in a 2014 FDA warning letter. The controller provides power to the HeartWare VAD and helps monitor it, but can fail due to electrostatic discharge (ESD). These failures may have resulted in the deaths of at least two patients and left four others seriously injured.

Both Thoratec and HeartWare are now conducting clinical trials to better evaluate the safety of their devices.

Doctors are being asked to conduct a thorough clinical evaluation on their patients to assess which device is appropriate and to consider these new warnings. They also ask that doctors return any devices that needed to be removed from patients and report any adverse events to the FDA.