The next-generation HeartMate 3 implantable pump St. Jude Medical (NYSE:STJ) acquired when it paid $3 billion for Thoratec last year proved superior to the older HeartMate II device at 6 months in pivotal clinical trial results released today.
The Momentum 3 study enrolled more than 1,000 patients for a short-term outcome after 6 months and a longer-term, 2-year outcome; the initial 6-month data comes from 294 subjects. Unlike the HeartMate II device, which uses an axial-flow pump, the HeartMate 3 device uses a centrifugal-flow pump designed to reduce the risk of blood clots.
The primary endpoint at 6 months was a composite of survival free of disabling stroke indicated by a modified Rankin score of >3 or survival free of re-operation to replace or remove the device (for reasons other than recovery). At 6 months, 86% of the HeartMate 3 cohort met the endpoint, compared with 77% of the HeartMate II group. Importantly, there was no incidence of blood clots with HeartMate 3 versus 18 incidents with HeartMate II.
“The rate of re-operation for pump malfunction was significantly lower in the centrifugal-flow pump group than in the axial-flow pump group, and this difference is the primary reason for the difference between the groups in the failure to reach the primary end point,” the study’s authors wrote today in the New England Journal of Medicine. “Only 1 patient (0.7%; 95% CI, 0 to 3.6) in the centrifugal-flow pump group underwent pump replacement (because of a drive-line communication fault resulting from moisture ingress that caused electrical failure), whereas 11 patients (7.7%, 95% CI, 3.9 to 13.4) in the axial-flow pump group underwent either a device exchange (9 patients) or device removal with urgent transplantation (2 patients) (P=0.002).”
“The Heartmate 3 [left ventricular assist system] improved clinical outcomes in the Momentum 3 study by avoiding the need for surgical re-operation to replace or remove the pump due to pump thrombosis,” Dr. Mandeep Mehra of Boston’s Brigham & Women’s Hospital and principal investigator, said in prepared remarks. “More importantly, these clinical gains occurred without an increase in other adverse events, providing important therapeutic progress for our advanced heart failure patients.”
“These data in the Momentum 3 study represent the continued advancement in therapy options available for patients living with debilitating heart failure,” added St. Jude medical director for mechanical circulatory support Dr. John O’Connell. “The HeartMate II LVAS is an extremely important medical advancement with more than 24,000 implants having occurred to date, and it is the only LVAD approved for both bridge-to-transplant and destination therapy options in the U.S. The data, now being seen with the HeartMate 3 LVAS, show that we are taking the next steps in advancing medical therapy options.”
“We met not only non-inferiority, but also superiority. We’re ecstatic with this,” Mehra told Reuters. “We are always looking for something that reduces the limitations of these devices,” he said. “We now have the HeartMate 3 that virtually eliminates one major complication that we see with left ventricular assistance.
“If you have a pump that does not require a repeat surgery to replace it, that is a very clear health economic advantage,” he said.
St. Jude closed the Thoratec acquisition in October 2015.