Left ventricular assist systems and infection-related outcomes: A comprehensive analysis of the MOMENTUM 3 trial

Background: In a randomized controlled trial (MOMENTUM 3), the HeartMate 3 (HM3) fully magnetically levitated centrifugal-flow left ventricular assist device (LVAD) demonstrated superiority over the HeartMate II (HMII) axial-flow LVAD. These findings were driven by hemocompatibility-related outcomes, but infection-related outcomes were not altered by device choice. In this trial-level analysis, we analyzed the clinical patterns of infection-related outcomes over 2 years of support.

Methods: In MOMENTUM 3, 1,020 patients were implanted with either the HM3 (n = 515) or HMII (n = 505) pump. Clinical characteristics and morbidity- and mortality-related outcomes were evaluated to identify predictors associated with major infectious complications, using univariable and multivariable models.

Results: The cumulative number of infections at 2 years was 1,213 (634 HM3 and 579 HMII), and major infection occurred in 58% of patients with the HM3 and 56% of patients with the HMII (p = 0.57). Infections of a local nature unrelated to pump components were most common (n = 681/1,213; 56%), followed by driveline-associated infection (n = 329/1,213; 27%), sepsis (n = 194/1,213; 16%), and other events (n = 9/1,213; 0.7%). Bacterial pathogens were implicated in 806 of 1,213 events (66%); significant predictors of infection included sex (women vs men; hazard ratio [HR]: 1.38, p = 0.003), pre-implant use of intra-aortic balloon pump (HR: 1.33, p = 0.02), pre-implant history of cardiac surgery (HR: 1.28, p = 0.01), and body mass index ≥ 30 (HR: 1.40, p < 0.0001). Most deaths in those with infection occurred owing to non-infectious causes.

Conclusion: Infection is the most common adverse effect in patients implanted with contemporary continuous-flow LVADs, with most such events unrelated to the pump or its peripheral components. Whether chronic mechanical circulatory devices confer an immunomodulatory effect pre-disposing to infection warrants closer scrutiny to understand and ameliorate this morbidity.