Thoratec HeartMate II Complications Linked to Pre-Operative Risks

Searching for a potential pattern in recent reports of complications with the Thoratec HeartMate II Left Ventricular Assist System (LVAS), researchers indicated that a number of pre-operative conditions could lead to bleeding and stroke once the artificial heart pump is implanted.  

In a study published this month by in the Journal of the American College of Cardiology (JACC), researchers from the Cleveland Clinic and a number of hospitals and universities nationwide examined the sharp increase in the rate of blood-clots associated with the HeartMate II in other recent studies. Researchers indicated that sex, age, body mass index and the cause of their heart failure could all be risk factors for bleeding stroke and pump thrombosis incidents.

The Thoratec HeartMate II LVAS, also known as a Left Ventricular Assist Device (LVAD), 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.

This new study comes following prior research published in November 2013, in which 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, researchers in this earlier study 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.

In this latest research, which also included scientists from Johns Hopkins Hospital in Baltimore, the Mayo Clinic, Columbia University, Duke University and from Thoratec itself, among others, researchers looked at data on 956 advanced heart failure patients to determine whether there may be common patterns to predict who may be at increased risk of Thoratec HeartMate II blood clots.

The findings suggest that being over the age of 65, female, having a lower pre-operative hematocrit and ischemic etiology were all statistically significant factors in whether the HeartMate II patient experienced post-operative bleeding. Being female or 65 years old or younger increased the risk of hemorrhagic stroke, while being female or having a history of diabetes increased the risk of ischemic stroke. The risk of pump thrombosis was increased by being female or having a higher body mass index.

The study did not address how those rates may have differed from someone who was not implanted with the HeartMate II.

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.