New-gen heart pump slashes thrombosis, improves stroke-free survival in MOMENTUM 3
The latest-generation left ventricular assist device (LVAD) HeartMate 3 is clinically superior to its predecessor HeartMate II in improving survival at 2 years free of disabling stroke or reoperation due to device malfunction in patients with advanced heart failure (HF), the MOMENTUM* 3 trial has shown.
In previous versions of LVAD, the risk of thrombosis and stroke complications has been the Achilles’ heel for the devices, limiting their long-term durability, said study co-investigator Dr Joseph Cleveland from the University of Colorado Hospital, Aurora, Colorado, US, who presented the study at ACC.18.
Calling the study a “much-needed step forward”, invited discussant Dr James Januzzi from Massachusetts General Hospital in Boston, Massachusetts, US, said during a press conference, “Perhaps the most dramatic finding of this study is the dramatic reduction in thrombosis events requiring reoperation … With this new technology, we’ve addressed the very important unmet need by reducing the onset of pump thrombosis, which is the precursor to either pump dysfunction or embolic stroke.”
HeartMate 3, a fully magnetically levitated centrifugal-flow pump, was previously associated with zero pump thrombosis events compared with the mechanical-bearing axial-flow pump HeartMate II in a short-term (6 months) analysis. [N Engl J Med 2017;376:440-450]
The current analysis proves the durability of HeartMate 3 through to 2 years to optimally support patients while they are waiting for heart transplantation (bridge-to-transplantation) or who are ineligible for transplantation and relying on an LVAD as lifelong therapy (destination therapy).
LVAD gaining MOMENTUM in advanced HF
Among the 366 patients (mean age 60 years) randomized, significantly more patients receiving HeartMate 3 survived up to 2 years free of disabling stroke (mRS* >3) or free of reoperation for device malfunction—the primary endpoint—than those on HeartMate II (79.5 percent vs 60.2 percent; p<0.001 for noninferiority). [ACC.18, abstract 405-08; N Engl J Med 2018;doi:10.1056/NEJMoa1800866]
Although originally designed to show noninferiority, the results demonstrated that the outcomes with HeartMate 3 were, in fact, superior to HeartMate II (hazard ratio [HR], 0.46; p<0.001 for superiority).
The difference was mainly driven by a 10-fold lower rate of reoperation for device malfunction in the HeartMate 3 vs the HeartMate II arms (1.6 percent vs 17.0 percent, HR, 0.08; p<0.001), of which two-thirds of the reoperations in the HeartMate II arm were for pump thrombosis or severe haemolysis. This translates to a 98 percent lower risk of reoperation for pump thrombosis or severe haemolysis with the newer- vs the older-generation LVAD (HR, 0.08; p<0.001).
Furthermore, the overall stroke rate was halved with HeartMate 3 (10.1 percent vs 19.2 percent, HR, 0.47; p=0.016), although the rates of disabling stroke and death were similar between the two groups.
“All of the benefit seen with the HeartMate 3 was in reducing the rate of nondisabling strokes,” said lead author Dr Mandeep Mehra of the Brigham and Women’s Hospital Heart and Vascular Center in Boston, Massachusetts, US. “The overall stroke rate [of 10 percent] at 2 years is the lowest recorded to date in an LVAD trial.”
The trial enrolled a target population with advanced HF and severe limitations (NYHA** IIIB or IV) who were refractory to guideline-mandated medical management and considered as necessary candidates for LVAD implantation, regardless of whether the intended goal of support was for bridge-to-transplantation or destination therapy.
With the results so promising, Januzzi raised the question “whether we should start thinking about a comparison [of LVAD vs heart] transplant in patients with advanced HF.”
“It’s worth at least considering this now, because there is such a shortage of organs available for transplantation that patients inevitably end up waiting, sometimes in hospital, sometimes unsuccessfully, for transplantation,” he said.