Thoratec manufactures the HeartMate II, a heart pump that was linked to a significant increase in blood clots, which may cause heart attack or stroke. Many patients have required emergency surgery, device transplant, or heart transplant. The sudden increase in blood clots is raising questions about whether Thoratec made an unannounced design change after March 2011 that increased patients’ risk of death.
UPDATE: HeartMate II Linked to 4 Deaths, 5 Injuries
March 5, 2014 — Thoratec Corporation has issued a Safety Advisory after receiving reports of four deaths and five injuries associated with the HeartMate II LVAS Pocket System Controller. Patients are at risk of problems when exchanging an older controller for the Pocket Controller. Click here to read more.
What is the Thoratec HeartMate II LVAD?
Thoratec manufactures that HeartMate II, a left ventricular assist device (LVAD) or system (LVAS), which is a mechanical heart pump that continually pushes blood through the heart. It is used in patients with advanced heart failure who are awaiting a heart transplant or are too weak to undergo surgery. Every year, about 4,000 people are implanted with an LVAD, and about 75% receive the HeartMate II.
HeartMate II Blood Clot Risk Highlighted in NEJM Study
In November 2013, the New England Journal of Medicine has published a study linking the HeartMate II to a four-fold increased risk of blood clots since March 2011. All of the patients who developed blood clots needed a device replacement, heart transplant, or died.
Researchers from the Cleveland Clinic found that 8.4% of patients who were implanted with the HeartMate II after March 2011 developed blood clots within three months of implantation. This is a sharp increase from 2.2% in earlier years.
A federally funded registry called INTERMACS shows a smaller increase in blood clots after March 2011 — about 5% after March 2011, compared to 2% in previous years. The same pattern was observed in four other hospitals and for multiple surgeons.
The study also showed faster blood clot development in patients implanted with the HeartMate II — the median time to clot formation was 2.7 months after March 2011, compared with 18.6 months in previous years. Overall, there were 72 cases of blood clots in 66 patients.
HeartMate II Blood Clot Injuries
- Cardiac arrhythmia
- Respiratory distress
- Malfunction of HeartMate II
- Heart attack
- Emergency heart transplant
- Surgery to remove the HeartMate II
Class 1 Recall of HeartMate II
April 4, 2012 — The U.S. Food and Drug Administration (FDA) has announced a Class 1 recall of the Thoratec HeartMate II Left Ventricular Assist System (LVAS). The problem is that a defective component may cause a kink or deformity that inhibits blood flow from the HeartMate II pump. In addition, the metal ends of the component may be sharp and cause erosion or cutting of the outflow graft. This could cause severe injury, including death.