Ventricular assist device using a thoracotomy-based implant technique: Multi-Center Implantation of the HeartMate 3 in Subjects With Heart Failure Using Surgical Techniques Other Than Full Median Sternotomy (HM3 SWIFT).

OBJECTIVES: The HeartMate 3 (Abbott) left ventricular assist device provides substantial improvement in long-term morbidity and mortality in patients with advanced heart failure. The Implantation of the HeartMate 3 in Subjects With Heart Failure Using Surgical Techniques Other Than Full Median Sternotomy study compares thoracotomy-based implantation clinical outcomes with standard median sternotomy. METHODS: We conducted a prospective, multicenter, single-arm study in patients eligible for HeartMate 3 implantation with thoracotomy-based surgical technique (bilateral thoracotomy or partial upper sternotomy with left thoracotomy). The composite primary end point was survival free of disabling stroke (modified Rankin score >3), or reoperation to remove or replace a malfunctioning device, or conversion to median sternotomy at 6-months postimplant (elective transplants were treated as a success). The primary end point (noninferiority, -15% margin) was assessed with >90% power compared with a propensity score-matched cohort (ratio 1:2) derived from the Multi-Center Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 continued access protocol. RESULTS: The study enrolled 102 patients between December 2020 and July 2022 in the thoracotomy-based arm at 23 North American centers. Follow-up concluded in December 2022. In the Implantation of the HeartMate 3 in Subjects With Heart Failure Using Surgical Techniques Other Than Full Median Sternotomy study group, noninferiority criteria was met (absolute between-group difference, -1.2%; Farrington Manning lower 1-sided 95% CI, -9.3%; P < .0025) and event-free survival was not different (85.0% vs 86.2%; hazard ratio, 1.01; 95% CI, 0.58-2.10). Length of stay with thoracotomy-based implant was longer (median, 20 vs 17 days; P = .03). No differences were observed for blood product utilization, adverse events (including right heart failure), functional status, and quality of life between cohorts. CONCLUSIONS: Thoracotomy-based implantation of the HeartMate 3 left ventricular assist device is noninferior to implantation via standard full sternotomy. This study supports thoracotomy-based implantation as an additional standard for surgical implantation of the HeartMate 3 left ventricular assist device.

Aspirin and Hemocompatibility Events With a Left Ventricular Assist Device in Advanced Heart Failure: The ARIES-HM3 Randomized Clinical Trial.

IMPORTANCE: Left ventricular assist devices (LVADs) enhance quality and duration of life in advanced heart failure. The burden of nonsurgical bleeding events is a leading morbidity. Aspirin as an antiplatelet agent is mandated along with vitamin K antagonists (VKAs) with continuous-flow LVADs without conclusive evidence of efficacy and safety. OBJECTIVE: To determine whether excluding aspirin as part of the antithrombotic regimen with a fully magnetically levitated LVAD is safe and decreases bleeding. DESIGN, SETTING, and PARTICIPANTS: This international, randomized, double-blind, placebo-controlled study of aspirin (100 mg/d) vs placebo with VKA therapy in patients with advanced heart failure with an LVAD was conducted across 51 centers with expertise in treating patients with advanced heart failure across 9 countries. The randomized population included 628 patients with advanced heart failure implanted with a fully magnetically levitated LVAD (314 in the placebo group and 314 in the aspirin group), of whom 296 patients in the placebo group and 293 in the aspirin group were in the primary analysis population, which informed the primary end point analysis. The study enrolled patients from July 2020 to September 2022; median follow-up was 14 months. Intervention: Patients were randomized in a 1:1 ratio to receive aspirin (100 mg/d) or placebo in addition to an antithrombotic regimen. MAIN OUTCOMES AND MEASURES: The composite primary end point, assessed for noninferiority (-10% margin) of placebo, was survival free of a major nonsurgical (>14 days after implant) hemocompatibility-related adverse events (including stroke, pump thrombosis, major bleeding, or arterial peripheral thromboembolism) at 12 months. The principal secondary end point was nonsurgical bleeding events. RESULTS: Of the 589 analyzed patients, 77% were men; one-third were Black and 61% were White. More patients were alive and free of hemocompatibility events at 12 months in the placebo group (74%) vs those taking aspirin (68%). Noninferiority of placebo was demonstrated (absolute between-group difference, 6.0% improvement in event-free survival with placebo [lower 1-sided 97.5% CI, -1.6%]; P < .001). Aspirin avoidance was associated with reduced nonsurgical bleeding events (relative risk, 0.66 [95% confidence limit, 0.51-0.85]; P = .002) with no increase in stroke or other thromboembolic events, a finding consistent among diverse subgroups of patient characteristics. CONCLUSIONS AND RELEVANCE: In patients with advanced heart failure treated with a fully magnetically levitated LVAD, avoidance of aspirin as part of an antithrombotic regimen, which includes VKA, is not inferior to a regimen containing aspirin, does not increase thromboembolism risk, and is associated with a reduction in bleeding events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04069156.

Predictors of 5-Year Mortality in Patients Managed With a Magnetically Levitated Left Ventricular Assist Device.

BACKGROUND: In advanced heart failure patients implanted with a fully magnetically levitated HeartMate 3 (HM3, Abbott) left ventricular assist device (LVAD), it is unknown how preimplant factors and postimplant index hospitalization events influence 5-year mortality in those able to be discharged. OBJECTIVES: The goal was to identify risk predictors of mortality through 5 years among HM3 LVAD recipients conditional on discharge from index hospitalization in the MOMENTUM 3 pivotal trial. METHODS: This analysis evaluated 485 of 515 (94%) patients discharged after implantation of the HM3 LVAD. Preimplant (baseline), implant surgery, and index hospitalization characteristics were analyzed individually, and as multivariable predictors for mortality risk through 5 years. RESULTS: Cumulative 5-year mortality in the cohort (median age: 62 years, 80% male, 65% White, 61% destination therapy due to transplant ineligibility) was 38%. Two preimplant characteristics (elevated blood urea nitrogen and prior coronary artery bypass graft or valve procedure) and 3 postimplant characteristics (hemocompatibility-related adverse events, ventricular arrhythmias, and estimated glomerular filtration rate <60 mL/min/1.73 m2 at discharge) were predictors of 5-year mortality. In 171 of 485 patients (35.3%) without any risk predictors, 5-year mortality was reduced to 22.6% (95% CI: 15.4%-32.7%). Even among those with 1 or more predictors, mortality was <50% at 5 years (45.7% [95% CI: 39.0%-52.8%]). CONCLUSIONS: Long-term survival in successfully discharged HM3 LVAD recipients is largely influenced by clinical events experienced during the index surgical hospitalization in tandem with baseline factors, with mortality of <50% at 5 years. In patients without identified predictors of risk, long-term 5-year mortality is low and rivals that achieved with heart transplantation, even though most were implanted with destination therapy intent. (MOMENTUM 3 IDE Clinical Study Protocol, NCT02224755; MOMENTUM 3 Pivotal Cohort Extended Follow-up PAS, NCT03982979).

Association of Angiopoetin-2 and TNF-α With Bleeding During Left Ventricular Assist Device Support: Analysis From the PREVENT Biorepository.

The purpose of this study was to describe the changes in plasma levels of angiogenic and inflammatory biomarkers, specifically Ang-2 and TNF-α, in patients receiving HeartMate II (HMII) left ventricular assist device (LVAD) and correlate them with nonsurgical bleeding. It has been shown that angiopoietin-2 (Ang-2) and tissue necrosis factor-α (TNF-α) may be linked to bleeding in LVAD patients. This study utilized biobanked samples prospectively collected from the PREVENT study, a prospective, multicenter, single-arm, nonrandomized study of patients implanted with HMII. Paired serum samples were obtained in 140 patients before implantation and at 90 days postimplantation. Baseline demographics were as follows: age 57 ± 13 years, 41% had ischemic etiology, 82% male, and 75% destination therapy indication. In the 17 patients with baseline elevation of both TNF-α and Ang-2, 10 (60%) experienced a significant bleeding event within 180 days postimplant compared with 37 of 98 (38%) patients with Ang-2 and TNF-α below the mean ( p = 0.02). The hazard ratio for a bleeding event was 2.3 (95% CI: 1.2-4.6) in patients with elevated levels of both TNF-α and Ang-2. In the PREVENT multicenter study, patients with elevations in serum Angiopoietin-2 and TNF-α at baseline before LVAD implantation demonstrated increased bleeding events after LVAD implantation.

Enhanced Thrombin Formation in Patients With Ventricular Assist Devices Experiencing Bleeding: Insights From the Multicenter PREVENT Study.

The aim of this investigation was to characterize the hemostatic status of heart failure patients with implanted left ventricular assist devices (LVADs) to propose a mechanism associated with bleeding. Patients (n = 300) from 23 US hospitals were enrolled in the PREVENtion of HeartMate II Pump Thrombosis through Clinical Management (PREVENT) study. A biobank was established with serum and plasma samples prospectively collected from a cohort of 175 patients preimplant baseline (BL) and 3 months (3M) postimplant. Outcomes were collected for 6 months. Thrombin (prothrombin fragment 1.2 [F1.2], functional thrombin generation [TG]) and fibrinolytic activity (D-dimer, plasminogen activator inhibitor-1 [PAI-1]), but not contact activation (complement C5a), were elevated in heart failure patients at BL. F1.2, TG, and PAI-1 levels decreased 3M after LVAD implantation ( p < 0.01) but did not revert to normal in all patients; conversely, D-dimer increased BL to 3M ( p < 0.01). Compared with patients without events, thrombin activity (F1.2) was increased in patients with late bleeding (3-4 months postimplant) ( p = 0.06) and in those with late gastrointestinal (GI) bleeding ( p = 0.01). Patients with 3M F1.2 levels above the cohort mean had a higher incidence of bleeding ( p < 0.001) and GI bleeding ( p < 0.001) compared with those with below mean F1.2. Patients experiencing multiple bleeding events were more likely to have 3M F1.2 greater than the cohort mean. Despite anticoagulation with aspirin and warfarin, LVAD implanted patients exhibit hemostatic activation. Excess thrombin formation, particularly shown by increased F1.2, was demonstrated in association with bleeding in LVAD implanted patients.

Incidence and clinical correlates of de-novo aortic regurgitation with a fully magnetically levitated left ventricular assist device: a MOMENTUM 3 trial portfolio analysis.

AIMS: We assessed the incidence, predictors and clinical correlates of de-novo aortic regurgitation (AR), which physiologically reduces left ventricular assist device (LVAD) effectiveness due to recirculation syndrome, in the MOMENTUM 3 trial portfolio of the fully magnetically levitated HeartMate 3 (HM3) pump using the randomized pivotal trial (PT) and post-trial continued access protocol (CAP). METHODS AND RESULTS: De-novo aortic regurgitation incidence at 2 years was analysed in the randomized PT and validated in the first 1000 implanted patients of the CAP. Patients with concomitant/prior aortic valve surgery or without baseline or post-implant echocardiograms were excluded from this analysis. AR severity was assessed qualitatively by site-adjudicated echocardiograms (significant AR was defined as moderate or severe grade on echocardiogram). Of 1028 patients enrolled in the PT, 918 were eligible for inclusion in this analysis (HM3, n = 465; HMII, n = 453). At 2 years of LVAD support, freedom from significant AR was greater in the HM3 (92%) than HMII (82%) (hazard ratio 0.45, 95% confidence interval 0.27-0.75, p < 0.01). Of 907 HM3 patients analysed from the first 1000 implanted CAP patients, the rate of freedom from significant AR was 90%, consistent with the PT (p = 0.3). In the combined HM3 group (n = 1372), multivariable Cox modelling identified increasing age and female sex as significant predictors. Survival free of urgent transplant or AR corrective procedure was similar between HM3 patients with and without significant de-novo AR. CONCLUSIONS: The development of moderate or severe grade de-novo AR is reduced with the fully magnetically levitated HM3 LVAD compared to the axial-flow HMII pump. The occurrence of significant de-novo AR with the HM3 pump is not associated with a worse outcome at 2 years of follow-up.

Aspirin and left ventricular assist devices: rationale and design for the international randomized, placebo-controlled, non-inferiority ARIES HM3 trial.

AIMS: Over decades, left ventricular assist device (LVAD) technology has transitioned from less durable bulky pumps to smaller continuous-flow pumps which have substantially improved long-term outcomes and quality of life. Contemporary LVAD therapy is beleaguered by haemocompatibility-related adverse events including thrombosis, stroke and bleeding. A fully magnetically levitated pump, the HeartMate 3 (HM3, Abbott, USA) LVAD, has been shown to be superior to the older HeartMate II (HMII, Abbott, USA) pump by improving haemocompatibility. Experience with the HM3 LVAD suggests near elimination of de-novo pump thrombosis, a marked reduction in stroke rates, and only a modest decrease in bleeding complications. Since the advent of continuous-flow LVAD therapy, patients have been prescribed a combination of aspirin and anticoagulation therapy on the presumption that platelet activation and perturbations to the haemostatic axis determine their necessity. Observational studies in patients implanted with the HM3 LVAD who suffer bleeding have suggested a signal of reduced subsequent bleeding events with withdrawal of aspirin. The notion of whether antiplatelet therapy can be avoided in an effort to reduce bleeding complications has now been advanced. METHODS: To evaluate this hypothesis and its clinical benefits, the Antiplatelet Removal and Hemocompatibility Events with the HeartMate 3 Pump (ARIES HM3) has been introduced as the first-ever international prospective, randomized, double-blind and placebo-controlled, non-inferiority trial in a patient population implanted with a LVAD. CONCLUSION: This paper reviews the biological and clinical role of aspirin (100 mg) with LVADs and discusses the rationale and design of the ARIES HM3 trial.

Effect of aspirin dose on hemocompatibility-related outcomes with a magnetically levitated left ventricular assist device: An analysis from the MOMENTUM 3 study.

BACKGROUND: Aspirin (ASA) anti-platelet therapy is mandated with left ventricular assist devices (LVADs) to prevent hemocompatibility-related adverse events (HRAEs). However, the optimal dose of ASA with HeartMate 3 (HM3) LVAD is unknown. METHODS: In an exploratory analysis of HM3-supported patients in the MOMENTUM 3 study (NCT02224755), 2 groups were analyzed: usual-dose (325 mg) and low-dose (81 mg) ASA with anti-coagulation targeted to an international normalized ratio of 2.0 to 3.0. Exclusion criteria included patients not receiving either ASA 81 mg or 325 mg, those with HRAEs ≤7 days after device implantation, and those receiving >1 anti-platelet agent. The primary end-point was survival free from HRAEs (non-surgical bleeding, pump thrombosis, stroke, and peripheral arterial thromboembolic events) at 2 years. RESULTS: Overall, 321 HM3 patients (usual-dose: n = 141, low-dose: n = 180) were included in this analysis. Usual-dose group patients were younger (57 ± 13 vs 60 ± 12 years, p = 0.035) and less often assigned destination therapy (55% vs 67%, p = 0.029) than low-dose ASA. At 2 years, a similar proportion of patients in the usual- and low-dose groups (43.4% vs 45.3%, p = 0.94) met the primary end-point. There were no differences in survival free from hemorrhagic (usual-dose: 54.4% vs low-dose: 51.7%, p = 0.42) or thrombotic (usual-dose: 76.8% vs low-dose: 75.7%, p = 0.92) events. CONCLUSIONS: Usual- and low-dose ASA revealed similar rates of bleeding and thrombotic events in HM3 LVAD-supported patients within the MOMENTUM 3 trial. Whether ASA therapy provides any meaningful therapeutic effect in patients treated by the HM3 LVAD remains to be determined.

Effects of a fully magnetically levitated centrifugal-flow or axial-flow left ventricular assist device on von Willebrand factor: A prospective multicenter clinical trial.

BACKGROUND: Increased shear stress conferred upon the circulation by continuous-flow pumps is associated with hemocompatibility-related adverse events, principally bleeding within the gastrointestinal system, and linked to the degradation of high-molecular-weight multimers (HMWMs) of von Willebrand factor (vWF). We evaluated the structure and functional characteristics of vWF HMWMs in patients with the fully magnetically levitated centrifugal-flow HeartMate 3 (HM3) and the continuous axial-flow HeartMate II (HMII) pump. Findings were correlated with bleeding events. METHODS: In a prospective, multicenter, comparative cohort study, 60 patients from the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 Continued Access Protocol (NCT02892955) with an HM3 pump were compared with 30 randomly selected HMII patients from the PREVENtion of HeartMate II Pump Thrombosis study (NCT02158403) biobank. The primary end point was the difference in the normalized vWF HMWM ratio (ratio of the HMWMs to the intermediate- and low-molecular-weight multimers, normalized to pooled plasma from healthy volunteers) between the HM3 and the HMII pump at 90 days after implantation. Assay tests for vWF activity, vWF antigen, vWF activity to antigen ratio, coagulation factor VIII activity, and ADAMTS13 activity were measured by using standard protocols. Differences in these markers were compared in the context of clinical characteristics and correlated with adjudicated bleeding events within the HM3 group. RESULTS: Of 51 and 29 evaluable patients in the HM3 and HMII arms, respectively, those implanted with the HM3 pump exhibited greater preservation of the vWF HMWM ratio than those with the HMII pump at 90 days after implantation (54.1% vs 42.4%, p < 0.0001). Laboratory values for all vWF assays (antigen, activity, and coagulation factor VIII activity) remained within the normal functional range with no significant differences observed between the pumps at 90 days after implantation. At baseline, there was a decrease in the structural integrity of vWF HMWMs that correlated with increasing heart failure severity as measured by the Interagency Registry for Mechanically Assisted Circulatory Support profile. Multivariable modeling identified the HM3 pump as the only independent variable that determined post-implantation preservation of the structural integrity of vWF HMWMs. CONCLUSIONS: This prospective, multicenter comparative analysis study demonstrates that the fully magnetically levitated centrifugal-flow HM3 left ventricular assist device is associated with greater preservation of the structure of vWF HMWMs than the HMII mechanical bearing axial-flow pump.

Comprehensive Analysis of Stroke in the Long-Term Cohort of the MOMENTUM 3 Study.

BACKGROUND: The MOMENTUM 3 study (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) has demonstrated that the HeartMate 3 (HM3) pump is associated with reduced strokes compared with the HeartMate II (HMII) device. We now perform a comprehensive analysis of stroke events to evaluate their longitudinal occurrence, clinical correlates, patterns, and impact on outcome across the 2-year duration of support. METHODS: MOMENTUM 3 is a randomized controlled trial of the HM3 centrifugal-flow pump versus the HMII axial-flow pump in patients with advanced heart failure, regardless of the intended goal of support (bridge to transplantation or destination therapy). Baseline and postimplantation clinical correlates of stroke events were assessed with multivariable analyses. Longitudinal patterns, including device association, type of stroke (hemorrhagic versus ischemic), changing severity of impairment assessed with the modified Rankin Scale (disabling [modified Rankin Scale score >3] versus nondisabling [modified Rankin Scale score ≤3]) over time, and association with outcome, were determined. RESULTS: In 361 patients with the intended implant (189 HM3 and 172 HMII), 65 strokes (40 ischemic strokes and 25 hemorrhagic strokes) occurred in 52 patients at a median of 131 (range, 1-733) days. No difference in stroke rate was noted between 0 and 180 days of follow-up between devices. However, stroke incidence in the long-term period (181-730 days after left ventricular assist device) was 3.3 times lower for the HM3 group (HM3: 0.04 versus HMII: 0.13 events per patient-year; odds ratio, 0.23; 95% CI, 0.08-0.63; P=0.01). Treatment with the HM3 pump was the only independent predictor of lower stroke events. We found no direct association of blood pressure or antithrombotic regimens with observed stroke rates. A stroke event significantly lowered 2-year postimplantation survival regardless of subtype or initial severity of neurological impairment compared with patients without a stroke (43±12% for hemorrhagic stroke, 57±9% for ischemic stroke, 51±11% for disabling, and 51±11% for nondisabling compared with 85±2% 2-year survival for patients without stroke). CONCLUSIONS: The HM3 pump is associated with a marked reduction in stroke rates compared with the HMII device, with benefits observed in the long-term period (>6 months). The occurrence of stroke of any type (hemorrhagic and ischemic) or of any functional severity (disabling and nondisabling) is predictive of a poor 2-year clinical outcome. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov/ . Unique identifier: NCT02224755.

Evaluation of low-intensity anti-coagulation with a fully magnetically levitated centrifugal-flow circulatory pump-the MAGENTUM 1 study.

BACKGROUND: The HeartMate 3 left ventricular assist system is engineered to avoid pump thrombosis, yet bleeding complications persist. We investigated the safety of low-intensity anti-coagulation in patients with the HeartMate 3. METHODS: The Minimal AnticoaGulation EvaluatioNTo aUgment heMocompatibility (MAGENTUM 1) pilot study is a prospective, single-arm study of low-intensity warfarin anti-coagulation in patients implanted with the HeartMate 3 pump. After standard warfarin anti-coagulation (international normalized ratio [INR] 2.0 to 3.0) and aspirin for 6 weeks post-implant, patients were transitioned to a lower INR target range of 1.5 to 1.9. The primary end-point was a composite of survival free of pump thrombosis, disabling stroke (modified Rankin score [MRS] >3), or major bleeding (excluding peri-operative bleeding) with at least 6-month post-implant follow-up. Time in therapeutic range (TTR) was measured to assess anti-coagulation target efficacy using the Rosendaal method. A safety algorithm to monitor for signs of pump thrombosis was developed and implemented. RESULTS: We enrolled 15 patients (mean age 57.3 ± 13.3 years), 13 men with advanced heart failure (67% with INTERMACS Profiles 2 or 3), irrespective of therapeutic goal of bridge-to-transplant or destination therapy. The primary end-point was met in 14 of 15 (93 ± 6%) patients; 1 patient developed recurrent gastrointestinal bleeding. The TTR during the reduced anti-coagulation phase (6 weeks to 6 months) was 75.3 ± 8.6%. No thrombotic events occurred. CONCLUSIONS: This pilot study suggests low-intensity anti-coagulation targeting an INR between 1.5 and 1.9 is achievable and safe with the HeartMate 3 cardiac pump in the short-term phase, 6-months post-implant. A large-scale trial is now warranted.