Hemocompatibility-Related Outcomes Associated With Magnetically Levitated Pump
What is the burden of bleeding and thrombosis events or hemocompatibility-related adverse events (HRAE) with the Heart Mate 3 Left Ventricular Assist System (LVAS)?
The study investigators performed a 6-month secondary analysis of HRAE (survival free of any nonsurgical bleeding, thromboembolic event, pump thrombosis, or neurological event) in the short-term cohort (as-treated cohort n = 289) of the MOMENTUM 3 trial (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3). They also assessed the net burden of HRAE by using a hemocompatibility score (HCS), which uses four escalating tiers of hierarchal severity to derive a total score for events encountered during the entire follow-up experience for each patient. Mild events (e.g., ≤2 nonsurgical) contributed a single point to the HCS, whereas serious events (e.g., disabling stroke) contributed a higher grade to the HCS (e.g., disabling stroke contributes 4 points). They conducted three separate analyses: a) comparison of HRAEs between HM3 and HMII LVAS, b) comparison of the net burden of HRAEs (assessed by the HCS) between the Heart Mate 3 (HM3) and Heart Mate II (HMII), and c) exploratory determination of clinical correlates predictive of HRAEs (based on an HCS >0). They used a multivariable logistic regression analysis to identify factors that were independently predictive of any HRAEs (HCS >0) or death in the full cohort of patients, with device type included as a covariate. They incorporated variables with p values < 0.1 on univariable analysis into the multivariable regression analysis.
The study cohort was comprised of 151 HM3 patients and 138 HMII patients, and more patients implanted with HM3 were alive free of HRAE at 6 months compared to patients supported with the HMII. The investigators found that survival free of any HRAE was achieved in 69% of the HM3 group and in 55% of the HMII group (hazard ratio, 0.62; confidence interval, 0.42-0.91; p = 0.012)—a 38% reduction in the hazard ratio in favor of the HM3. Overall improvement in survival free of HRAEs with the HM3 was more pronounced in patients ≤65 years of age (p = 0.01), whereas in those >65 years, there were 26 events in the HM3 group, and 23 events in the HMII group, p = 0.17). Utilizing HCS, the HM3 group demonstrated less pump thrombosis requiring reoperation (0 vs. 36 points, p < 0.001) or medically managed pump thrombosis (0 vs. 5 points, p = 0.02), and fewer non-disabling strokes (6 vs. 24 points, p = 0.026) than the control HMII LVAS. They also reported that net HCS in the HM3 when compared to HMII patients was 101 (0.67 ± 1.50 points/patient) versus 137 (0.9 9± 1.79 points/patient) (odds ratio, 0.64; confidence interval, 0.39-1.03; p = 0.065).
The study authors concluded that HM3 LVAS demonstrated greater freedom from HRAEs in comparison with the HMII LVAS at 6 months.
Although the study follow-up is for a relatively short period, the findings are important because it suggests that magnetically levitated pumps are superior to their predecessors when it comes to thrombotic and bleeding complications associated with left ventricular assist devices. Await longer-term follow-up data from these investigators.
Clinical Topics: Anticoagulation Management, Cardiac Surgery, Geriatric Cardiology, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Cardiac Surgery and Heart Failure, Acute Heart Failure, Mechanical Circulatory Support
Keywords: Anticoagulants, Biocompatible Materials, Cardiac Surgical Procedures, Geriatrics, Heart-Assist Devices, Heart Failure, Hemorrhage, Reoperation, Stroke, Thromboembolism, Thrombosis
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