Left Ventricular Dimensions and Clinical Outcomes With a Fully Magnetically Levitated Left Ventricular Assist Device

Background: Prior analyses have suggested that a smaller left ventricular end-diastolic diameter (LVEDD) is associated with reduced survival following HeartMate 3 left ventricular assist device implantation.

Objectives: In this trial-based comprehensive analysis, the authors sought to examine clinical characteristics and association with the outcome of this specific relationship.

Methods: The authors analyzed the presence of LVEDD <55 mm among 1,921 analyzable HeartMate 3 patients within the MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) trial portfolio, on endpoints of overall survival and adverse events at 2 years. Adverse events included hemocompatibility-related (stroke, bleeding, and pump thrombosis) and non-hemocompatibility-related (right heart failure, infection) outcomes.

Results: Those with a smaller LVEDD (<55 mm) (n = 108) were older (age 63 ± 11 years vs 60 ± 12 years; P = 0.005), were more often female (31% vs 20%; P = 0.096), and had more ischemic cardiomyopathy (60.2% vs 42.6%; P = 0.0004) compared with the LVEDD ≥55 mm group (n = 1,813). Death during implant hospitalization was higher (14.8 vs 5.7%; P = 0.0007) and survival at 2 years was lower (63.3% vs 81.8%; HR: 1.97 [95% CI: 1.39-2.79]; P = 0.0002) in the LVEDD <55 mm group. The LVEDD <55 mm group experienced more deaths due to hemocompatibility-related adverse events (2.8% vs 0.6%; HR: 4.61 [95% CI: 1.29-16.45]; P = 0.018) and right heart failure, both early (0-30 days; 7.4% vs 2.0%; HR: 3.70 [95% CI: 1.73-7.91]; P = 0.001) and late (>30 days; 12.0 vs 4.8%; HR: 2.58 [95% CI: 1.37-4.84]; P = 0.003). Low-flow alarms rehospitalizations were higher in the LVEDD <55 mm cohort (17.4 vs 8.3%; HR: 2.39 [95% CI: 1.59-3.59]; P < 0.001).

Conclusions: Although infrequent in occurrence, smaller LVEDD (<55 mm) is associated with increased risk for early and late mortality, a consequence of hemocompatibility-related and right heart failure-related deaths. Rehospitalizations due to low-flow alarms are also more frequent. (MOMENTUM 3 IDE Clinical Study Protocol [HM3™]; NCT02224755; MOMENTUM 3 Continued Access Protocol [MOMENTUM 3 CAP]; NCT02892955).