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

In Vitro Comparison of Device-Induced Hemolysis, Platelet Defects, and von Willebrand Factor Degradation Between the HeartMate 2 and HeartMate 3 Pumps

BACKGROUND

Left ventricular assist devices (LVADs) have been utilized to maintain the circulatory demands of patients with end-stage heart failure. Despite their positive impact, hemocompatibility-related adverse events remain a major challenge. The aim of this study is to compare in vitro hemocompatibility performance between the HeartMate 2 (HM2) and HeartMate 3 (HM3) pumps by assessing device-induced blood damage in an in vitro circulatory loop.

METHODS

Fresh healthy human blood was circulated for 4 h in a circulatory loop assisted by an HM2 or HM3 pump at a flow rate of 4.5 L/min and a pressure head of 75 mmHg. Hourly blood samples were collected for analysis of hemolysis, platelet activation, platelet receptor shedding, and high molecular weight multimer (HMWM) degradation of von Willebrand factor (VWF).

RESULTS

The data from the hourly blood samples showed that the HM3 pump caused significantly lower levels of hemolysis, platelet activation, platelet receptor shedding, and HMWM degradation of VWF compared to the HM2 pump.

CONCLUSION

The HM3 exhibited superior overall hemocompatibility to the HM2, underscoring the advantages of the fully magnetically levitated centrifugal pump design in the HM3 compared to the mechanical bearing-supported axial pump design of the HM2.

Concomitant Surgical Procedures and Aspirin Avoidance With Left Ventricular Assist Device Therapy

BACKGROUND

ARIES-HM3 (Antiplatelet Removal and Hemocompatibility Events With the HeartMate 3 Pump) demonstrated that aspirin avoidance with a fully magnetically levitated HeartMate 3 (HM3) left ventricular assist device (LVAD) reduces bleeding complications and does not increase thromboembolism. Whether a concomitant surgical procedure modifies the observed safety and benefits remains uncertain.

OBJECTIVES

This prespecified analysis of ARIES-HM3 studied clinical outcomes when concomitant surgical procedures are performed during LVAD implantation with excluding aspirin but maintaining a vitamin K antagonist.

METHODS

Among 628 patients randomized to receive either placebo or aspirin with a vitamin K antagonist, 589 (296 placebo and 293 aspirin) contributed to the primary endpoint analysis. Sub-categorization with receiving a concomitant surgical procedure (valvular procedure/coronary artery bypass grafting or nonvalvular procedure) was done and the composite primary endpoint of survival free from major nonsurgical (>14 days postimplant) hemocompatibility-related adverse events at 12 months was assessed.

RESULTS

There were 155 (52%) and 145 (49%) concomitant procedures in placebo and aspirin arms, respectively. The percentage of subjects achieving primary endpoint success was higher with the placebo group in patients with a concomitant procedure, and no interaction was observed on primary outcomes between those with and without concomitant surgical procedures (Pint = 0.231, 0.298, and 0.735 for any procedure, valvular/coronary artery bypass grafting, and nonvalvular procedures, respectively). There was a similar reduction in nonsurgical major hemorrhagic events with placebo compared with aspirin, observed in patients with or without any concomitant procedure: 0.64 (95% CI: 0.44-0.94) and 0.66 (95% CI: 0.46-0.93).

CONCLUSIONS

Our findings support the safety and efficacy of aspirin avoidance from the antithrombotic regimen in HM3 LVAD patients undergoing concomitant surgical procedures. (Antiplatelet Removal and Hemocompatibility Events With the HeartMate 3 Pump [ARIES-HM3]; NCT04069156).

Cost-Effectiveness of Left Ventricular Assist Device for Transplant-Ineligible Patients

Importance

Singapore is considering subsidizing left ventricular assist devices (LVADs) for end-stage heart failure (ESHF) and uses cost-effectiveness evidence to inform the determination. Yet, no economic evaluation has thus far been conducted.

Objective

To estimate the lifetime cost-effectiveness of LVAD compared with optimal medical management for transplant-ineligible patients.

Design, Setting, and Participants

This economic evaluation used a Markov model to simulate survival, stroke incidence, other adverse events, and heart failure hospitalizations for a cohort of adult patients in Singapore with transplant-ineligible ESHF, most of whom were inotrope dependent. Latest LVAD mortality data from a randomized clinical trial were age-adjusted, and an indirect comparison of prior trial results was performed to estimate survival for inotrope-dependent and inotrope-independent patients. Costs were estimated (in 2023 Singapore dollars [SGD]) using cohort billing data from 2017 to 2022 and National Heart Centre Singapore LVAD charges. Statistical analysis was performed from December 2023 to July 2024.

Exposure

HeartMate 3 LVAD (Abbott).

Main Outcomes and Measures

Health care costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) evaluated against a threshold of SGD 114 000 (US $85 075) per QALY gained.

Results

At model initiation, the cohort had a mean (SD) age of 64 (12) years, and 78% (range, 68%-86%) of patients were inotrope dependent. In the base case analysis, LVAD yielded an additional 3.45 QALYs at an incremental cost of SGD 404 678 (US $301 999), producing an ICER of SGD 117 370 (US $87 590) per QALY gained for the transplant-ineligible population. The ICER differed for inotrope-use subgroups at SGD 106 458 (US $79 446) per QALY gained for inotrope-dependent patients and SGD 174 798 (US $130 446) per QALY gained for inotrope-independent patients (with 59% and 19% probabilities, respectively, of attaining high value). The inotrope-dependent ICER was sensitive to model input changes and structural assumptions, whereas the inotrope-independent ICER consistently exceeded the high-value threshold in scenario analyses. In threshold analyses, a 44% reduction in the total implantation price or a 54% reduction in the all-cause mortality hazard were required for LVAD to be high value for inotrope-independent patients. Confidence that the inotrope-dependent ICER is high value increased to 75% and 85% with respective 20% and 33% reductions in total implantation price.

Conclusions and Relevance

In this economic evaluation comparing LVAD with optimal medical management, LVAD was potentially high value for most transplant-ineligible patients who are inotrope dependent. Confidence in this result was improved with plausible price reductions, yet only extreme changes rendered LVAD high value for inotrope-independent patients.

Early stroke following durable left ventricular assist device (LVAD) implantation: An analysis of the Society of Thoracic Surgeons Intermacs National Database

BACKGROUND

Stroke remains a devastating complication of durable left ventricular assist device (LVAD) therapy. This study evaluated the incidence and risk factors for early stroke within 7 days following LVAD implantation investigating both traditional pre-implant and new intraoperative variables collected by The Society of Thoracic Surgeons (STS) Intermacs National Database.

METHODS

STS Intermacs was queried for patients undergoing implantation of a fully magnetically levitated centrifugal LVAD between November 25, 2020 and June 30, 2023. STS Intermacs stroke definitions were used to identify patients who suffered a stroke within the first 7 postoperative days (POD). A multivariable logistic regression model was created to generate adjusted odd ratios (OR) for variables associated with early stroke.

RESULTS

Among 6,950 patients in the study cohort, 5.9% (413/6950) developed a stroke after a median follow-up of 11 months, with 50% (205/413) of strokes occurring within 7 days after LVAD implantation. Of the strokes occurring during POD 0-7, 70% (144/205) occurred on POD 0-2. By multivariable analysis, the following factors were associated with early stroke: older age (70 vs 50; OR 1.4, p = 0.0129), white race (OR 1.5, p = 0.0078), pre-implant temporary mechanical circulatory support (MCS) bridge (temporary LVAD only: OR 1.6, extracorporeal membrane oxygenation [ECMO] only: OR 1.7, combination of both devices: OR 3.3; p = 0.0001) and presence of an unremoved left atrial clot (OR 8.0, p < 0.0001).

CONCLUSIONS

A significant proportion of strokes occur within the first 7 days following LVAD implantation, particularly within the first 2 days. In addition to pre-implant variables, we identified modifiable intraoperative factors associated with stroke that provide an opportunity for further risk mitigation and improvement in quality of care.

Cost-effectiveness of Left Ventricular Assist Devices (LVADs) as destination therapy in the UK: An economic modelling study

OBJECTIVES

Left Ventricular Assist Devices (LVADs) for destination therapy (DT) are used in many countries but in some, like the UK, LVADs are not commissioned due to uncertainty around their cost-effectiveness. Existing economic evaluations of LVADs for these patients have limitations. This study aimed to estimate the cost-effectiveness of LVADs as destination therapy, compared to optimal medical therapy, in the UK.

METHODS

A cost-utility analysis from a UK healthcare perspective was conducted, using a Markov model. The model incorporated the impact of major events and complications. Sub-group analyses considered different severities of heart failure on cost-effectiveness. Uncertainty was measured in deterministic and probabilistic sensitivity analyses.

RESULTS

LVAD produced additional 2.78 (95% CI 2.46-3.14) QALYs at an incremental cost of £152,329 (95% CI £125,665 - £181,812) compared to medical management, giving an incremental cost-effectiveness ratio (ICER) of £54,748 per QALY. The ICER remained above the accepted thresholds of cost-effectiveness in the UK if a small proportion of patients receiving LVAD becomes eligible for a heart transplant and for all subgroups based on heart failure severity. The deterministic sensitivity analysis showed that the ongoing outpatient costs had a significant impact on the results.

CONCLUSIONS

Our analysis found that LVADs are not cost-effective as destination therapy in the UK if a willingness to pay threshold of £50,000 per QALY gained or disease severity modifiers, were applied. Robust data on ongoing costs for LVAD and medical management are needed.

Durable left ventricular assist devices: a contemporary review of their benefits and drawbacks

INTRODUCTION

Heart transplantation, the gold standard for end-stage cardiomyopathy, is hindered by donor shortages and clinical deterioration. Left ventricular assist devices (LVADs) have emerged as crucial alternatives, stabilizing hemodynamics, reversing end-organ damage, and enabling patient discharge. Significant engineering advancements and iterative improvements have since produced devices capable of rivaling heart transplantation in early survival potential. This review serves to provide an overview of LVAD technology, an understanding of current device limitations, and preview new technologies being developed to address them.

AREAS COVERED

This manuscript reviews the evolution of LVAD technology, discussing its benefits, drawbacks, and contemporary outcomes. It will detail the progression, current state, and future directions of LVAD technology, emphasizing its pivotal role in managing advanced heart failure.

EXPERT OPINION

The modern day LVAD has significantly extended the lifespan of patients with end-stage heart failure. However, adverse events remain abound and will be the focus of the next generation of devices. A burgeoning pipline of new technologies abound and preview the possibilities of a sustainable solution to a devastating disease.

Dynamic Risk Estimation of Adverse Events in Ambulatory LVAD Patients: A MOMENTUM 3 Analysis

BACKGROUND

Hemocompatibility-related adverse events affect patients after left ventricular assist device (LVAD) implantation but are hard to predict.

OBJECTIVES

Dynamic risk modeling with a multistate model can predict risk of gastrointestinal bleeding (GIB), stroke, or death in ambulatory patients.

METHODS

This was a secondary analysis of the MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3) trial. HeartMate 3 LVAD recipients who survived to hospital discharge and were followed for up to 2 years. A total of 145 variables were included in the multistate model with multivariate logistic regression. Model performance was assessed with the area under the curve in a holdout validation cohort. A risk stratification tool was created by dividing patients into categories of predicted risk using the final model variables and associated OR.

RESULTS

Among 2,056 LVAD patients, the median age was 59.4 years (20.4% women, 28.6% Black). At 2 years, the incidence of GIB, stroke, and death was 25.6%, 6.0%, and 12.3%, respectively. The multistate model included 39 total variables to predict risk of GIB (16 variables), stroke (10 variables), and death (19 variables). When ambulatory patients were classified according to their risk category, the 30-day observed event rate in the highest risk group for GIB, stroke, or death was 26.9%, 1.8%, and 4.8%, respectively. The multistate model predicted GIB, stroke, and death at any 30-day period with an area under the curve of 0.70, 0.69, and 0.86, respectively.

CONCLUSIONS

The multistate model informs 30-day risk in ambulatory LVAD recipients and allows recalculation of risk as new patient-specific data become available. The model allows for accurate risk stratification that predicts impending adverse events and may guide clinical decision making. (MOMENTUM 3 IDE Clinical Study Protocol; NCT02224755).

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Stroke outcomes following durable left ventricular assist device implant in patients bridged with micro-axial flow pump: Insights from a large registry

BACKGROUND

Stroke after durable left ventricular assist device (d-LVAD) implantation portends high mortality. The incidence of ischemic and hemorrhagic stroke and the impact on stroke outcomes of temporary mechanical circulatory support (tMCS) management among patients requiring bridge to d-LVAD with micro-axial flow-pump (mAFP, Abiomed) is unsettled.

METHODS

Consecutive patients, who underwent d-LVAD implantation after being bridged with mAFP at 19 institutions, were retrospectively included. The incidence of early ischemic and hemorrhagic stroke after d-LVAD implantation (<60 days) and association of pre-d-LVAD characteristics and peri-procedural management with a specific focus on tMCS strategies were studied.

RESULTS

Among 341 patients, who underwent d-LVAD implantation after mAFP implantation (male gender 83.6%, age 58 [48-65] years, mAFP 5.0/5.5 72.4%), the early ischemic stroke incidence was 10.8% and early hemorrhagic stroke 2.9%. The tMCS characteristics (type of mAFP device and access, support duration, upgrade from intra-aortic balloon pump, ECMELLA, ECMELLA at d-LVAD implantation, hemolysis, and bleeding) were not associated with ischemic stroke after d-LVAD implant. Conversely, the device model (mAFP 2.5/CP vs. mAFP 5.0/5.5: HR 5.6, 95%CI 1.4-22.7, p = 0.015), hemolysis on mAFP support (HR 10.5, 95% CI 1.3-85.3, p = 0.028) and ECMELLA at d-LVAD implantation (HR 5.0, 95% CI 1.4-18.7, p = 0.016) were associated with increased risk of hemorrhagic stroke after d-LVAD implantation. Both early ischemic (HR 2.7, 95% CI 1.9-4.5, p < 0.001) and hemorrhagic (HR 3.43, 95% CI 1.49-7.88, p = 0.004) stroke were associated with increased 1-year mortality.

CONCLUSIONS

Among patients undergoing d-LVAD implantation following mAFP support, tMCS characteristics do not impact ischemic stroke occurrence, while several factors are associated with hemorrhagic stroke suggesting a proactive treatment target to reduce this complication.

In Vitro and In Silico Characterization of the Aggregation of Thrombi on Textured Ventricular Cannula

The unacceptably high stroke rate associated with HeartMate 3 ventricular assist device (VAD) without signs of adherent pump thrombosis is hypothesized to be the result of the emboli produced by the inflow cannula, that are ingested and ejected from the pump. This in vitro and numerical study aimed to emulate the surface features and supraphysiological shear of a ventricular cannula to provide insight into their effect on thrombogenesis. Human whole blood was perfused at calibrated flow rates in a microfluidic channel to achieve shear rates 1000-7500 s-1, comparable to that experienced on the cannula. The channel contained periodic teeth representative of the rough sintered surface of the HeartMate 3 cannula. The deposition of fluorescently labeled platelets was visualized in real time and analyzed with a custom entity tracking algorithm. Numerical simulations of a multi-constituent thrombosis model were performed to simulate laminar blood flow in the channel. The sustained growth of adherent platelets was observed in all shear conditions ( p <  0.05). However, the greatest deposition was observed at the lower shear rates. The location of deposition with respect to the microfluidic teeth was also found to vary with shear rate. This was confirmed by CFD simulation. The entity tracking algorithm revealed the spatial variation of instances of embolic events. This result suggests that the sintered surface of the ventricular cannula may engender unstable thrombi with a greater likelihood of embolization at supraphysiological shear rates.

An ISHLT consensus statement on strategies to prevent and manage hemocompatibility related adverse events in patients with a durable, continuous-flow ventricular assist device

Life expectancy of patients with a durable, continuous-flow left ventricular assist device (CF-LVAD) continues to increase. Despite significant improvements in the delivery of care for patients with these devices, hemocompatability-related adverse events (HRAEs) are still a concern and contribute to significant morbility and mortality when they occur. As such, dissemination of current best evidence and practices is of critical importance. This ISHLT Consensus Statement is a summative assessment of the current literature on prevention and management of HRAEs through optimal management of oral anticoagulant and antiplatelet medications, parenteral anticoagulant medications, management of patients at high risk for HRAEs and those experiencing thrombotic or bleeding events, and device management outside of antithrombotic medications. This document is intended to assist clinicians caring for patients with a CF-LVAD provide the best care possible with respect to prevention and management of these events.

A Computational Investigation of the Effects of Temporal Synchronization of Left Ventricular Assist Device Speed Modulation with the Cardiac Cycle on Intraventricular Hemodynamics

Patients with advanced heart failure are implanted with a left ventricular assist device (LVAD) as a bridge-to-transplantation or destination therapy. Despite advances in pump design, the risk of stroke remains high. LVAD implantation significantly alters intraventricular hemodynamics, where regions of stagnation or elevated shear stresses promote thrombus formation. Third generation pumps incorporate a pulsatility mode that modulates rotational speed of the pump to enhance in-pump washout. We investigated how the timing of the pulsatility mode with the cardiac cycle affects intraventricular hemodynamic factors linked to thrombus formation. Computational fluid dynamics simulations with Lagrangian particle tracking to model platelet behavior in a patient-specific left ventricle captured altered intraventricular hemodynamics due to LVAD implantation. HeartMate 3 incorporates a pulsatility mode that modulates the speed of the pump every two seconds. Four different timings of this pulsatility mode with respect to the cardiac cycle were investigated. A strong jet formed between the mitral valve and inflow cannula. Blood stagnated in the left ventricular outflow tract beneath a closed aortic valve, in the near-wall regions off-axis of the jet, and in a large counterrotating vortex near the anterior wall. Computational results showed good agreement with particle image velocimetry results. Synchronization of the pulsatility mode with peak systole decreased stasis, reflected in the intraventricular washout of virtual contrast and Lagrangian particles over time. Temporal synchronization of HeartMate 3 pulsatility with the cardiac cycle reduces intraventricular stasis and could be beneficial for decreasing thrombogenicity.

HeartMate 3 implantation with an emphasis on the biventricular configuration

OBJECTIVES

Right ventricular failure following implantation of a durable left ventricular assist device (LVAD) is a major driver of mortality. Reported survival following biventricular (BiVAD) or total artificial heart (TAH) implantation remains substantially inferior to LVAD alone. We report our outcomes with LVAD and BiVAD HeartMate 3 (HM3).

METHODS

Consecutive patients undergoing implantation of an HM3 LVAD between November 2014 and December 2021, at The Alfred, Australia were included in the study. Comparison was made between the BiVAD and LVAD alone groups.

RESULTS

A total of 86 patients, 65 patients with LVAD alone and 21 in a BiVAD configuration underwent implantation. The median age of the LVAD and BiVAD groups was 56 years (Interquartile range 46-62) and 49 years (Interquartile range 37-55), respectively. By 4 years after implantation, 54% of LVAD patients and 43% of BiVAD patients had undergone cardiac transplantation. The incidence of stroke in the entire experience was 3.5% and pump thrombosis 5% (all in the RVAD). There were 14 deaths in the LVAD group and 1 in the BiVAD group. The actuarial survival for LVAD patients at 1 year was 85% and BiVAD patients at 1 year was 95%.

CONCLUSIONS

The application of HM 3 BiVAD support in selected patients appears to offer a satisfactory solution to patients requiring biventricular support.

Computational investigation of outflow graft variation impact on hemocompatibility profile in LVADs

BACKGROUND

Hemocompatibility-related adverse events (HRAE) occur commonly in patients with left ventricular assist devices (LVADs) and add to morbidity and mortality. It is unclear whether the outflow graft orientation can impact flow conditions leading to HRAE. This study presents a simulation-based approach using exact patient anatomy from medical images to investigate the influence of outflow cannula orientation in modulating flow conditions leading to HRAEs.

METHODS

A 3D model of a proximal aorta and outflow graft was reconstructed from a computed tomography (CT) scan of an LVAD patient and virtually modified to model multiple cannula orientations (n = 10) by varying polar (cranio-caudal) (n = 5) and off-set (anterior-posterior) (n = 2) angles. Time-dependent computational flow simulations were then performed for each anatomical orientation. Qualitative and quantitative hemodynamics metrics of thrombogenicity including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell platelet activation potential (ECAP), particle residence time (PRT), and platelet activation potential (PLAP) were analyzed.

RESULTS

Within the simulations performed, endothelial cell activation potential (ECAP) and particle residence time (PRT) were found to be lowest with a polar angle of 85°, regardless of offset angle. However, polar angles that produced parameters at levels least associated with thrombosis varied when the offset angle was changed from 0° to 12°. For offset angles of 0° and 12° respectively, flow shear was lowest at 65° and 75°, time averaged wall shear stress (TAWSS) was highest at 85° and 35°, and platelet activation potential (PLAP) was lowest at 65° and 45°.

CONCLUSION

This study suggests that computational fluid dynamic modeling based on patient-specific anatomy can be a powerful analytical tool when identifying optimal positioning of an LVAD. Contrary to previous work, our findings suggest that there may be an "ideal" outflow cannula for each individual patient based on a CFD-based hemocompatibility profile.

Generation of Pulsatile Flow using Clinical Continuous Flow Pumps

Background

With the increasing use of mechanical circulatory support for long-term augmentation of cardiopulmonary function, the need for safer devices is apparent. Pump thrombosis and failure, inadequate ventricular unloading, progressive right-sided dysfunction, and end-organ hypoperfusion are seen with long-term mechanical circulatory support devices. Generation of pulsatile flow has been proposed to mitigate some of these risks by providing physiologic flow and pressure profiles to the vascular system and end-organs. Modification of continuous flow devices to provide pulsatility may prove a cheap and effective way to achieve physiologic flow; however, effective use of such a technique has yet to be demonstrated. This work aims to describe these efforts, as well as mechanical arguments regarding the challenges to be overcome in achieving this goal.

Methods

Prior literature and textbooks were used to develop the theoretical basis for the paper.

Results

Attempts at generating pulsatile flow with continuous flow devices have been marred by difficulty in mitigating viscous effects on oscillating mechanical systems. Currently available devices and research setups have been unable to generate truly physiologic pulsatile flow systems. New devices are needed that utilize various forms of positive displacement in order to generate true pulsatile flow that mimic native waveforms generated by the heart.

Conclusions

The mechanical challenges in generating pulsatile flow with continuous flow devices have precluded their widespread adoption in clinical practice. New pulsatile pumps are needed to achieve adequate physiologic pulsatility with improved side-effect profile.

Organ blood flow assessment with the ModulHeart cardiorenal support device

BACKGROUND

ModulHeart (Puzzle Medical Devices Inc) is a novel percutaneous flow entrainment pump anchored in the descending aorta. The current study evaluates the hemodynamic effect of ModulHeart support and its impact on cerebral, myocardial, and renal blood flow.

METHODS

ModulHeart was implanted in the descending aorta of four healthy calves. A ramp protocol (2000 RPM increments) was performed with the pump operating at five different speeds from 14 000 to 22 000 RPM. For each speed, pressures proximal and distal to the pump, and right heart catheterization measurements were recorded. Stable-isotope labeled microspheres were injected in the left ventricle to evaluate organ perfusion.

RESULTS

Thermodilution cardiac output increased by 23% at 22 000 RPM. Greater pump speeds resulted in greater pump gradients, up to 10 mm Hg in mean arterial pressure at 22 000 RPM, without significant reduction of proximal perfusion pressures. Arterial pulse pressure remained stable at all speeds. ModulHeart was not associated with a reduction in cerebral or myocardial blood flow at any speed. Renal cortical and medullary blood flow increased by up to 50% and 40%, respectively.

CONCLUSION

The ModulHeart device implanted in the descending aorta of healthy calves resulted in significant arterial pressure gradients and preserved pulse pressure. Greater pump speeds translated into greater increases in renal blood flow, with no decrease in cerebral or myocardial perfusion.

Evolution of Mechanical Circulatory Support for advanced heart failure

This comprehensive review highlights the significant advancements in Left Ventricular Assist Device (LVAD) therapy, emphasizing its evolution from the early pulsatile flow systems to the cutting-edge continuous-flow devices, particularly the HeartMate 3 (HM3) LVAD. These advancements have notably improved survival rates, reduced complications, and enhanced the quality of life (QoL) for patients with advanced heart failure. The dual role of LVADs, as a bridge-to-transplantation and destination therapy is discussed, highlighting the changing trends and policies in their application. The marked reduction in hemocompatibility-related adverse events (HRAE) with the HM3 LVAD, compared to previous models signifies ongoing progress in the field. Challenges such as managing major infections are discussed, including innovative solutions like energy transfer systems aimed at eliminating external drivelines. It explores various LVAD-associated complications, including HRAE, infections, hemodynamic-related adverse events, and cardiac arrhythmias, and underscores emerging strategies for predicting post-implantation outcomes, fostering a more individualized patient care approach. Tools such as the HM3 risk score are introduced for predicting survival based on pre-implant factors, along with advanced imaging techniques for improved complication prediction. Additionally, the review highlights potential new technologies and therapies in LVAD management, such as hemodynamic ramp tests for optimal speed adjustment and advanced remote monitoring systems. The goal is to automate LVAD speed adjustments based on real-time hemodynamic measurements, indicating a shift towards more effective, patient-centered therapy. The review concludes optimistically that ongoing research and potential future innovations hold the promise of revolutionizing heart failure management, paving the way for more effective and personalized treatment modalities.

Clinical Outcomes With a Fully Magnetically Levitated Left Ventricular Assist Device Among Women and Men

BACKGROUND

Left ventricular assist devices (LVADs) are underused among women with advanced heart failure, but reasons remain unclear. Outcomes in women compared with men with contemporary fully magnetically levitated LVADs remain uncertain.

OBJECTIVES

The authors examined differences in characteristics, 2-year outcomes, and risk for key adverse events among women and men.

METHODS

In 2,200 HeartMate3 (HM3) (Abbott Cardiovascular) LVAD recipients in the MOMENTUM 3 study (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3), survival free of disabling stroke or reoperation to replace or remove a malfunctioning pump at 2 years was analyzed between women and men. Other outcomes included overall 2-year survival, adverse events, and functional measures.

RESULTS

Women comprised 20.4% (n = 448 of 2,200) of the study population and were younger, with nonischemic cardiomyopathy, and more often were Black persons compared with men. The primary endpoint (women 79.4% vs men 75.5% (adjusted [a]HR: 0.96 [95% CI: 0.75-1.24]; P = 0.66) or survival at 2 years (women 82.4% vs men 80.2%; aHR: 1.06 [95% CI: 0.81-1.40]; P = 0.66) was no different. Women had an increased rate of stroke (adjusted incidence rate ratio [aIRR]: 1.52 [95% CI: 1.09-2.11]; P = 0.012), major bleeding (aIRR: 1.28 [95% CI: 1.15-1.42]; P < 0.0001) and infection (aIRR 1.14 [95% CI: 1.03-1.55]; P = 0.01), but these differences were not seen among older (>65 years) patients. Both groups had similar gains in 6-minute walk distance and quality-of-life measurements.

CONCLUSIONS

There were no differences in the primary composite endpoint or overall survival in women compared with men at 2 years of support. Reasons underlying increase in hemocompatibility-related events and infection-related morbidity in younger women deserves further study. (MOMENTUM 3 IDE [HM3], NCT02224755; MOMENTUM 3 Continued Access Protocol [MOMENTUM 3 CAP], NCT02892955).

Thrombotic and Hemorrhagic Complications Following Left Ventricular Assist Device Placement: An Emphasis on Gastrointestinal Bleeding, Stroke, and Pump Thrombosis

The left ventricular assist device (LVAD) is a mechanical circulatory support device that supports the heart failure patient as a bridge to transplant (BTT) or as a destination therapy for those who have other medical comorbidities or complications that disqualify them from meeting transplant criteria. In patients with severe heart failure, LVAD use has extended survival and improved signs and symptoms of cardiac congestion and low cardiac output, such as dyspnea, fatigue, and exercise intolerance. However, these devices are associated with specific hematologic and thrombotic complications. In this manuscript, we review the common hematologic complications of LVADs.

Stroke and Mechanical Circulatory Support in Adults

PURPOSE OF THE REVIEW

Short-term and durable mechanical circulatory support (MCS) devices represent life-saving interventions for patients with cardiogenic shock and end-stage heart failure. This review will cover the epidemiology, risk factors, and treatment of stroke in this patient population.

RECENT FINDINGS

Short-term devices such as intra-aortic balloon pump, Impella, TandemHeart, and Venoatrial Extracorporal Membrane Oxygenation, as well as durable continuous-flow left ventricular assist devices (LVADs), improve cardiac output and blood flow to the vital organs. However, MCS use is associated with high rates of complications, including ischemic and hemorrhagic strokes which carry a high risk for death and disability. Improvements in MCS technology have reduced but not eliminated the risk of stroke. Mitigation strategies focus on careful management of anti-thrombotic therapies. While data on therapeutic options for stroke are limited, several case series reported favorable outcomes with thrombectomy for ischemic stroke patients with large vessel occlusions, as well as with reversal of anticoagulation for those with hemorrhagic stroke. Stroke in patients treated with MCS is associated with high morbidity and mortality. Preventive strategies are targeted based on the specific form of MCS. Improvements in the design of the newest generation device have reduced the risk of ischemic stroke, though hemorrhagic stroke remains a serious complication.

Is it time to stop living in a HeartMate II world?

Despite improving outcomes with modern pump technology, left ventricular assist device (LVAD) utilization for patients with end-stage heart failure (HF) has declined significantly in the preceding half-decade. Here, we examine this trend, noting an inherent contradiction in the declining utilization of an improving therapeutic option. We propose a series of provocative questions as a "call to action" for the field of advanced HF to consider both scientifically and clinically, focusing on our evaluation parameters for LVAD candidacy, our approach to dichotomous LVAD vs transplant decisions, and our current management paradigms. We conclude that modernization in these areas to match the advantages of modern pump technology is required to best serve patients with advanced HF.

Durable Mechanical Circulatory Support: JACC Scientific Statement

Despite advances in medical therapy for patients with stage C heart failure (HF), survival for patients with advanced HF is <20% at 5 years. Durable left ventricular assist device (dLVAD) support is an important treatment option for patients with advanced HF. Innovations in dLVAD technology have reduced the risk of several adverse events, including pump thrombosis, stroke, and bleeding. Average patient survival is now similar to that of heart transplantation at 2 years, with 5-year dLVAD survival now approaching 60%. Unfortunately, greater adoption of dLVAD therapy has not been realized due to delayed referral of patients to advanced HF centers, insufficient clinician knowledge of contemporary dLVAD outcomes (including gains in quality of life), and deprioritization of patients with dLVAD support waiting for heart transplantation. Despite these challenges, novel devices are on the horizon of clinical investigation, offering smaller size, permitting less invasive surgical implantation, and eliminating the percutaneous lead for power supply.

Pulsatility and flow patterns across macro- and microcirculatory arteries of continuous-flow left ventricular assist device patients

BACKGROUND

Reduced arterial pulsatility in continuous-flow left ventricular assist devices (CF-LVAD) patients has been implicated in clinical complications. Consequently, recent improvements in clinical outcomes have been attributed to the "artificial pulse" technology inherent to the HeartMate3 (HM3) LVAD. However, the effect of the "artificial pulse" on arterial flow, transmission of pulsatility into the microcirculation and its association with LVAD pump parameters is not known.

METHODS

The local flow oscillation (pulsatility index, PI) of common carotid arteries (CCAs), middle cerebral arteries (MCAs) and central retinal arteries (CRAs-representing the microcirculation) were quantified by 2D-aligned, angle-corrected Doppler ultrasound in 148 participants: healthy controls, n = 32; heart failure (HF), n = 43; HeartMate II (HMII), n = 32; HM3, n = 41.

RESULTS

In HM3 patients, 2D-Doppler PI in beats with "artificial pulse" and beats with "continuous-flow" was similar to that of HMII patients across the macro- and microcirculation. Additionally, peak systolic velocity did not differ between HM3 and HMII patients. Transmission of PI into the microcirculation was higher in both HM3 (during the beats with "artificial pulse") and in HMII patients compared with HF patients. LVAD pump speed was inversely associated with microvascular PI in HMII and HM3 (HMII, r2 = 0.51, p < 0.0001; HM3 "continuous-flow," r2 = 0.32, p = 0.0009; HM3 "artificial pulse," r2 = 0.23, p = 0.007), while LVAD pump PI was only associated with microcirculatory PI in HMII patients.

CONCLUSIONS

The "artificial pulse" of the HM3 is detectable in the macro- and microcirculation but without creating a significant alteration in PI compared with HMII patients. Increased transmission of pulsatility and the association between pump speed and PI in the microcirculation indicate that the future clinical care of HM3 patients may involve individualized pump settings according to the microcirculatory PI in specific end-organs.

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).

In Vitro Investigation of the Effect of the Timing of Left Ventricular Assist Device Speed Modulation on Intraventricular Flow Patterns

Thromboembolic events remain a common complication for left ventricular assist device (LVAD) patients. To prevent in-pump thrombosis, third-generation LVADs use speed modulation, which is not synchronized with the native left ventricle (LV) contractility. This study aims to investigate the effect of speed modulation on intraventricular flow patterns, and specifically, the impact of timing relative to pressure variations in the LV. Stereo-particle image velocimetry measurements were performed in a patient-derived LV implanted with an LVAD, for different timings of the speed modulation and speed. Speed modulation has a strong effect on instantaneous afterload and flowrate (-16% and +20%). The different timings of the speed modulation resulted in different flowrate waveforms, exhibiting different maxima (5.3-5.9 L/min, at constant average flowrate). Moreover, the timing of the speed modulation was found to strongly influence intraventricular flow patterns, specifically, stagnation areas within the LV. These experiments highlight, once more, the complex relationship between LVAD speed, hemodynamic resistance, and intraventricular pressure. Overall, this study demonstrates the importance of considering native LV contractility in future LVAD controls, to improve hemocompatibility and reduce the risk of thromboembolic complications.

Stroke and pump thrombosis following left ventricular assist device implantation: The impact of the implantation technique

Objectives

Several studies have shown the potential advantage of less-invasive surgery (LIS) for left ventricular assist device (LVAD) implantation. This study aims to determine the impact of LIS on stroke and pump thrombosis events after LVAD implantation.

Methods

Between January 2015 and March 2021, 335 consecutive patients underwent LVAD implantation using either conventional sternotomy (CS) or the LIS technique. Patient characteristics was prospectively collected. All patients were followed up until October 2021. Logistic multivariate regression and propensity-matched analyses were performed to account for confounding factors.

Results

A total of 242 patients (F = 32; 13.0%) underwent LVAD implantation with CS and 93 patients (F = 8; 8.6%) with the LIS approach. Propensity matching generated two groups, including 98 patients in the CS group and 67 in the LIS group. Intensive care unit stay for the LIS group patients was significantly shorter than that for the CS group patients [2 (IQR: 2-5) days vs. 4 (IQR: 2-12) days, p < 0.01]. There were no significant differences in the incidence of stroke events (14% in CS vs. 16% in the LIS group; p = 0.6) or in pump thrombosis (6.1% in CS vs. 7.5% in the LIS group; p = 0.8) between the groups. The hospital mortality rate in the matched cohort was significantly lower in the LIS group (7.5% vs. 19%; p = 0.03). However, the 1-year mortality rate showed no significant difference between both groups (24.5% in CS and 17.9% in LIS; p = 0.35).

Conclusions

The LIS approach for LVAD implantation is a safe procedure with potential advantage in the early postoperative period. However, the LIS approach remains comparable to the sternotomy approach in terms of postoperative stroke, pump thrombosis, and outcome.

Artificial Muscles and Soft Robotic Devices for Treatment of End-Stage Heart Failure

Medical soft robotics constitutes a rapidly developing field in the treatment of cardiovascular diseases, with a promising future for millions of patients suffering from heart failure worldwide. Herein, the present state and future direction of artificial muscle-based soft robotic biomedical devices in supporting the inotropic function of the heart are reviewed, focusing on the emerging electrothermally artificial heart muscles (AHMs). Artificial muscle powered soft robotic devices can mimic the action of complex biological systems such as heart compression and twisting. These artificial muscles possess the ability to undergo complex deformations, aiding cardiac function while maintaining a limited weight and use of space. Two very promising candidates for artificial muscles are electrothermally actuated AHMs and biohybrid actuators using living cells or tissue embedded with artificial structures. Electrothermally actuated AHMs have demonstrated superior force generation while creating the prospect for fully soft robotic actuated ventricular assist devices. This review will critically analyze the limitations of currently available devices and discuss opportunities and directions for future research. Last, the properties of the cardiac muscle are reviewed and compared with those of different materials suitable for mechanical cardiac compression.

HFSA Expert Consensus Statement on the Medical Management of Patients on Durable Mechanical Circulatory Support

The medical management of patients supported with durable continuous flow left ventricular assist device (LVAD) support encompasses pharmacologic therapies administered in the preoperative, intraoperative, postoperative and chronic LVAD support stages. As patients live longer on LVAD support, the risks of LVAD-related complications and progression of cardiovascular and other diseases increase. Using existing data from cohort studies, registries, randomized trials and expert opinion, this Heart Failure Society of America Consensus Document on the Medical Management of Patients on Durable Mechanical Circulatory Support offers best practices on the management of patients on durable MCS, focusing on pharmacological therapies administered to patients on continuous flow LVADs. While quality data in the LVAD population are few, the utilization of guideline directed heart failure medical therapies (GDMT) and the importance of blood pressure management, right ventricular preload and afterload optimization, and antiplatelet and anticoagulation regimens are discussed. Recommended pharmacologic regimens used to mitigate or treat common complications encountered during LVAD support, including arrhythmias, vasoplegia, mucocutaneous bleeding, and infectious complications are addressed. Finally, this document touches on important potential pharmacological interactions from anti-depressants, herbal and nutritional supplements of relevance to providers of patients on LVAD support.

Mechanical thrombectomy after acute ischemic stroke in patients with left ventricular assist devices: A nationwide analysis

INTRODUCTION

Left ventricular assist devices (LVADs) are an established, durable, and life-saving treatment option for patients with advanced heart failure. However, large vessel occlusions (LVOs) remain one of its most devastating embolic complications. Mechanical thrombectomy (MT) is safe and effective in the management of LVOs in the general population, but LVO trials largely excluded patients on mechanical circulatory support, and large-scale analyses of outcomes following these interventions in the LVAD population are lacking.

METHODS

Using the National Inpatient Sample, we identified all adult patients hospitalized with acute ischemic stroke (AIS) from 2005 to 2018. Regression models adjusting for patient demographics, hospital factors, and clinical severity were used to compare outcomes following MT in patients with and without LVAD. Subgroup analyses were also performed in LVAD patients experiencing stroke in the post-operative setting and stroke in the setting of pre-existing devices.

RESULTS

Of the 1,633,234 AIS hospitalizations identified, 794 occurred in patients with LVADs. Around 61% were post-operative. Post-stroke in-hospital mortality was higher among patients with LVADs (23.3% vs 7.23%, P < 0.001). Among those receiving MT, mortality was also higher in the LVAD population (31.0% vs 14.1%, P = 0.009), though this was largely driven by the post-operative LVAD subgroup. In multivariable analysis, only post-operative LVAD patients experienced greater odds of in-hospital death after MT (adjusted odds ratio (aOR): 8.66, confidence interval (CI):1.46-51.3); patients with pre-existing LVADs demonstrated no difference in post-MT mortality (aOR: 1.06; 95% CI: 0.29-3.91) or in odds of discharge home after MT (aOR 0.63, CI: 0.17-2.32).

CONCLUSION

Our data suggest MT is not a futile treatment approach in patients with pre-existing LVADs and may result in similar rates of good outcomes. Additional research is needed to evaluate the long-term benefits of endovascular therapy after stroke in patients on LVAD support.

Stroke Complications in Patients Requiring Durable Mechanical Circulatory Support Systems After Extracorporeal Life Support

Stroke is one of the leading complications following durable mechanical circulatory support (MCS) implantation. The aim of this multicenter study was to investigate stroke complications in patients requiring durable MCS following extracorporeal life support (ECLS). Data of 11 high volume MCS centers were collected and evaluated to identify patients who underwent durable MCS implantation after ECLS support between January 2010 and August 2018. The primary outcome was stroke following durable MCS implantation. Univariate and multivariate logistic regression analyses were performed to determine predictors of stroke. Overall, 531 patients met the inclusion criteria. Only patients who were supported with continuous flow pumps were included in this study accounting for 495 patients (median age 54 years old [interquartile range 47-60]). A total of 136 patients (27%) developed postoperative stroke on device during the follow-up (48% ischemic and 52% hemorrhagic) after a median durable MCS support of 320 [32-1,000] days, accounting for 0.17 events per patient-year. Of 133 patients with known date of stroke, a total of 47 (10%) developed stroke during the first 30 days (64% ischemic and 36% hemorrhagic), and 86 patients developed stroke after 30 days (38% ischemic and 62% hemorrhagic) of durable MCS support (late stroke). Survival rate was significantly lower in patients with hemorrhagic stroke ( p = 0.00091). Stroke appears to be a common complication in patients transitioned to durable MCS support after ECLS. Hemorrhagic stroke is a more common type of late stroke and is associated with inferior outcomes.

Anticoagulation alone as an effective and safe antithrombotic therapy in LVAD: When less is more

To evaluate the safety and effectiveness of anticoagulation alone in HeartMate3 patients. According to antithrombotic regimen, patients were divided into 2 groups: Group-1(warfarin+aspirin) and Group-2(warfarin). A comparison of hemocompatibility-related adverse events (HRAEs), hemocompatibility score (HCS), and hemocoagulative laboratory markers, both qualitative and quantitative, between the 2 groups were performed. Fifty patients were enrolled, 28 (56%) in Group-1 and 22 in Group-2 (44%), without statistical differences at baseline. Median time of follow-up was 590 days (IQR: 410.25-1007.50). Eighteen HRAEs (36.0%) occurred: 17 in Group-1 (34%) and 1 in Group-2 (2%) (P < 0.001). The net HCS for Group-1 versus Group-2 was 24 points and 1 point (OR 12.116[2.034-233.226], P = 0.023), respectively. Hemocoagulative values turned into the normality and remained stable during follow-up, without differences between groups, except for ASPI-test (P = 0.003). HeartMate3 showed a high hemocompatibility independently from antithrombotic therapy. Aspirin avoidance resulted a safe and effective strategy since it reduced hemorrhagic events, without increasing thrombotic risk.

Impact of Left Atrial or Left Atrial Appendage Thrombus on Stroke Outcome: A Matched Control Analysis

BACKGROUND AND PURPOSE

Left atrial or left atrial appendage (LA/LAA) thrombi are frequently observed during cardioembolic evaluation in patients with ischemic stroke. This study aimed to investigate stroke outcomes in patients with LA/LAA thrombus.

METHODS

This retrospective study included patients admitted to a single tertiary center in Korea between January 2012 and December 2020. Patients with nonvalvular atrial fibrillation who underwent transesophageal echocardiography or multi-detector coronary computed tomography were included in the study. Poor outcome was defined as modified Rankin Scale score >3 at 90 days. The inverse probability of treatment weighting analysis was performed.

RESULTS

Of the 631 patients included in this study, 68 (10.7%) had LA/LAA thrombi. Patients were likely to have a poor outcome when an LA/LAA thrombus was detected (42.6% vs. 17.4%, P<0.001). Inverse probability of treatment weighting analysis yielded a higher probability of poor outcomes in patients with LA/LAA thrombus than in those without LA/LAA thrombus (P<0.001). Patients with LA/LAA thrombus were more likely to have relevant arterial occlusion on angiography (36.3% vs. 22.4%, P=0.047) and a longer hospital stay (8 vs. 7 days, P<0.001) than those without LA/LAA thrombus. However, there was no difference in early neurological deterioration during hospitalization or major adverse cardiovascular events within 3 months between the two groups.

CONCLUSIONS

Patients with ischemic stroke who had an LA/LAA thrombus were at risk of a worse functional outcome after 3 months, which was associated with relevant arterial occlusion and prolonged hospital stay.

Left Ventricular Assist Devices: A Primer For the General Cardiologist

Durable implantable left ventricular assist devices (LVADs) have been shown to improve survival and quality of life for patients with stage D heart failure. Even though LVADs remain underused overall, the number of patients with heart failure supported with LVADs is steadily increasing. Therefore, general cardiologists will increasingly encounter these patients. In this review, we provide an overview of the field of durable LVADs. We discuss which patients should be referred for consideration of advanced heart failure therapies. We summarize the basic principles of LVAD care, including medical and surgical considerations. We also discuss the common complications associated with LVAD therapy, including bleeding, infections, thrombotic issues, and neurologic events. Our goal is to provide a primer for the general cardiologist in the recognition of patients who could benefit from LVADs and in the principles of managing patients with LVAD. Our hope is to "demystify" LVADs for the general cardiologist.

Left atrial appendage exclusion with less invasive left ventricular assist device implantation

OBJECTIVES

The objective of this single-center, pilot, prospective, and historical control study is to evaluate safety and feasibility outcomes associated with left atrial appendage exclusion (LAAE) concomitant with left ventricular assist device (LVAD) implantation via less invasive surgery (LIS) as a stroke prevention strategy.

METHODS

A predefined number of 30 eligible subjects scheduled for LIS LVAD with LAAE were enrolled in the prospective arm between January 2020 and February 2021. Eligible retrospective LIS LVAD patients without LAAE were propensity-matched in a 1:1 ratio with the prospective arm subjects. The primary study objectives were to evaluate the safety, feasibility, and efficacy of the LAAE concomitant with LIS LVAD.

RESULTS

Preoperative characteristics of patients in the Non-LAAE and LAAE groups were similar. LAAE was successfully excluded in all prospective patients (100%). Primary safety endpoints of chest tube output within the first 24 postoperative hours, Reoperation for bleeding within 48 h, and index hospitalization mortality demonstrated comparable safety of LAAE versus Non-LAAE with LIS LVAD. Cox proportional hazard regression demonstrated that LAAE with LIS LVAD was associated with 37% and 49% reduction in the risk of stroke and disabling stroke, respectively (p > .05).

CONCLUSION

Results from our pilot study demonstrated the safety and feasibility of LAAE concomitant with LIS LVAD as a stroke prevention strategy. This is the first prospective study describing LAAE performed concomitantly to less invasive LVAD implantation. The efficacy of LAAE in long-term stroke prevention needs to be confirmed in future prospective randomized clinical trials.

Post-Implant Phosphodiesterase-5 Inhibitors in Patients with Left Ventricular Assist Device: A Systematic Review and Meta-Analysis

Background: Despite the improvement in left ventricular assist device (LVAD) technology and the advent of third-generation LVADs, hemocompatibility-related events remain a significant issue. Therefore, new pharmacological treatments are necessary to optimize patient management and to further reduce hemocompatibility-related events. The purpose of the present systematic review and meta-analysis was to summarize the existing data regarding the safety and efficacy of post-implant phosphodiesterase-5 inhibitors (PDE-5i) on hemocompatibility-related events. Methods: Among the 258 articles in Pubmed, Scopus, and CENTRAL that were retrieved (1990−2022), 15 studies were included in the qualitative synthesis, and 9 studies were included in the quantitative synthesis. The fixed-effects model was used because it is statistically sound for combining a very small number of studies. The primary endpoint of the study was all-cause mortality, whereas the secondary endpoints were ischemic stroke, pump thrombosis, and gastrointestinal bleeding. Results: Mortality was significantly lower in the PDE-5i group vs. the control group (OR: 0.92 [95% CI: 0.85, 0.98]; p = 0.02). The secondary endpoints ischemic stroke (OR: 0.87 [95% CI: 0.78, 0.98]; p = 0.02) and pump thrombosis (OR: 0.90 [95% CI: 0.82, 0.99]; p = 0.04) were also lower in the PDE-5i group. The incidence of gastrointestinal bleeding was significantly higher in patients with LVAD receiving PDE-5i (OR: 1.26 [95% CI: 1.11, 1.44]; p < 0.01). In the overall analysis, the heterogeneity of outcomes was low, except for pump thrombosis. Conclusions: The use of PDE-5i post-implant was associated with lower mortality and thrombotic events but with a higher risk of gastrointestinal bleeding.

Cost-effectiveness of a centrifugal-flow pump for patients with advanced heart failure in Argentina

Background

Centrifugal-flow pumps are novel treatment options for patients with advanced heart failure (HF). This study estimated the incremental cost-effectiveness ratio (ICER) of centrifugal-flow pumps for patients with advanced HF in Argentina.

Methods

Two Markov models were developed to estimate the cost-effectiveness of a centrifugal-flow pump as destination therapy (DT) in patients with contraindication for heart transplantation, and as bridge-to-transplant (BTT), with a lifetime horizon using the third-party payer Social Security (SS) and Private Sector (PS) perspectives. Clinical, epidemiological, and quality-adjusted life years (QALY) parameters were retrieved from the literature. Direct medical costs were estimated through a micro-costing approach (exchange rate USD 1 = ARS 59.95).

Results

The centrifugal-flow pump as a DT increased the per patient QALYs by 3.5 and costs by ARS 8.1 million in both the SS and PS, with an ICER of ARS 2.3 million per QALY. Corresponding values for a centrifugal-flow pump as BTT were 0.74 QALYs and more than ARS 8 million, yielding ICERs of ARS 11 million per QALY (highly dependent on waiting times). For the 1, 3, and 5 GDP per QALY thresholds, the probability of a centrifugal-flow pump to be cost-effective for DT/BTT was around 2%/0%, 40%/0%, and 80%/1%, respectively.

Conclusion

The centrifugal-flow pump prolongs life and improves the quality of life at significantly higher costs. As in Argentina there is no current explicit cost-effectiveness threshold, the final decision on reimbursement will depend on the willingness to pay in each subsector. Nevertheless, the centrifugal-flow pump as a DT was more cost-effective than as a BTT.

Third-generation continuous-flow left ventricular assist devices: a comparative outcome analysis by device type

AIMS

Continuous-flow left ventricular assist devices (CF-LVADs) have become a standard of care in end-stage heart failure. Limited data exist comparing outcomes of HeartMate3 (HM3) and HeartWare HVAD (HW). We aimed to compare midterm outcomes of these devices.

METHODS AND RESULTS

Investigator-initiated retrospective-observational comparative analysis of all patients who underwent primary LVAD implantation of either HM3 or HW at our centre between January 2010 and December 2020. Data were derived from a prospective registry. Primary endpoints were all-cause mortality and heart transplantation. Secondary endpoints included device-related major adverse cardiac and cerebrovascular events, which included major bleeding, major neurological dysfunction (defined as persisting neurological impairment for ≥24 h), device-related major infection (excluding driveline infections), major device malfunctions leading to re-intervention or partial device exchange (pump failure, outflow-graft twist or failure, controller failure, battery failure, patient cable failure, but excluding pump thrombosis), and pump thrombosis. Further secondary endpoints included right heart failure, gastrointestinal bleeding, driveline infections, and surgical re-interventions. The secondary outcomes were analysed not only for the first event but also for recurrent events. The analysis included competing risks analysis and recurrent event regression analysis, with adjustment for confounders age, gender, body mass index (BMI), and Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level. Out of 106 primary CF-LVAD implantations, 36 (34%) received HM3 and 70 (66%) received HW. Median follow-up was 1.48 years [interquartile range 0.67, 2.41]. HM3 was more often implanted in men (91.7% vs. 72.9%, P = 0.024); patients were older (median 61 years [54, 66.5] vs. 52.5 years [43, 60], P < 0.001), had a higher BMI (median 26.7 kg/m² [23.4, 29.0] vs. 24.3 kg/m² [20.7, 27.4], P = 0.013), had more comorbidities, and were more likely targeted for destination therapy (36.1% vs. 14.3%, P = 0.010). Death occurred in 33.3% of HM3 patients, compared with 22.9% of HW patients, P = 0.247 (probability of survival at 4 years, 54.7% vs. 74.1%, P = 0.296). After adjustment for confounders, we observed a significant six-fold risk increase in device malfunctions for HW [hazard ratio (HR) 6.49, 95% confidence interval (CI) [1.89, 22.32], P = 0.003], but no significant differences in pump thrombosis (P = 0.173) or overall survival (P = 0.801).

CONCLUSIONS

Comparing midterm outcomes between HM3 and HW for LVAD support from a prospective registry, HW patients had a significantly higher risk of device malfunctions. No significant differences were evident between devices in overall survival and in respect to most outcomes.

Management of Hypertension in Patients With Ventricular Assist Devices: A Scientific Statement From the American Heart Association

Mechanical circulatory support with durable continuous-flow ventricular assist devices has become an important therapeutic management strategy for patients with advanced heart failure. As more patients have received these devices and the duration of support per patient has increased, the postimplantation complications have become more apparent, and the need for approaches to manage these complications has become more compelling. Continuous-flow ventricular assist devices, including axial-flow and centrifugal-flow pumps, are the most commonly used mechanical circulatory support devices. Continuous-flow ventricular assist devices and the native heart have a constant physiological interplay dependent on pump speed that affects pressure-flow relationships and patient hemodynamics. A major postimplantation complication is cerebrovascular vascular accidents. The causes of cerebrovascular vascular accidents in ventricular assist device recipients may be related to hypertension, thromboembolic events, bleeding from anticoagulation, or some combination of these. The most readily identifiable and preventable cause is hypertension. Hypertension management in these patients has been hampered by the fact that it is difficult to accurately measure blood pressure because these ventricular assist devices have continuous flow and are often not pulsatile. Mean arterial pressures have to be identified by Doppler or oscillometric cuff and treated. Although guidelines for hypertension management after ventricular assist device implantation are based largely on expert consensus and conventional wisdom, the mainstay of treatment for hypertension includes guideline-directed medical therapy for heart failure with reduced ejection fraction because this may reduce adverse effects associated with hypertension and increase the likelihood of favorable ventricular remodeling. The use of systemic anticoagulation in ventricular assist device recipients may at a given blood pressure increase the risk of stroke.

Six-month outcomes in postapproval HeartMate3 patients: A single-center US experience

BACKGROUND

The European CE Mark approval study and the MOMENTUM 3 trial demonstrated safety and a reduction in hemocompatibility-related adverse events with the use of HeartMate 3 (HM3) device. This single-center study investigated the real-world experience in HM3 patients since FDA approval.

METHODS

This retrospective, observational study included patients implanted with the HM3 LVAD as a primary implant between October 2017 and March 2020. Patients were divided into trial group and postapproval group. The primary endpoint was survival at 6 months. Secondary endpoints were adverse events including pump thrombosis (requiring pump exchange), stroke, renal failure, acute limb ischemia, re-exploratory for bleeding, gastrointestinal bleeding, right ventricular failure, and driveline infection.

RESULTS

A total of 189 patients were implanted with HM3 device during the study period. 174 patients met the inclusion criteria: 82 patients in the trial group and 92 patients in the postapproval group. The postapproval group had younger patients, higher preoperative mean international normalized ratio, and greater numbers of patients with bridge to transplant (BTT) indications, IINTERMACS profile 1, and use of mechanical assist devices (other than IABP) than the trial group. Other characteristics between the two groups were comparable. Overall survival at 6 months in the postapproval group was 93.3% versus 93.8% (p = .88). The postapproval group demonstrated a statistically significant lower incidence of re-explorative surgery for bleeding (10.9% vs. 46.3, p = .01) than the trial group.

CONCLUSION

In this single-center study, the real-world 6-month survival in the postapproval group was comparable to the trial results. Further studies are needed to monitor long-term outcomes.

The History of Durable Left Ventricular Assist Devices and Comparison of Outcomes: HeartWare, HeartMate II, HeartMate 3, and the Future of Mechanical Circulatory Support

The utilization of left ventricular assist devices (LVADs) in end-stage heart failure has doubled in the past ten years and is bound to continue to increase. Since the first of these devices was approved in 1994, the technology has changed tremendously, and so has the medical and surgical management of these patients. In this review, we discuss the history of LVADs, evaluating survival and complications over time. We also aim to discuss practical aspects of the medical and surgical management of LVAD patients and future directions for outcome improvement in this population.

Trends and Outcomes of Left Ventricular Assist Device Therapy: JACC Focus Seminar

As the prevalence of advanced heart failure continues to rise, treatment strategies for select patients include heart transplantation or durable left ventricular assist device (LVAD) support, both of which improve quality of life and extend survival. Recently, the HeartMate 3 has been incorporated into clinical practice, the United Network for Organ Sharing donor heart allocation system was revised, and the management of LVAD-related complications has evolved. Contemporary LVAD recipients have greater preoperative illness severity, but survival is higher and adverse event rates are lower compared with prior eras. This is driven by advances in device design, patient selection, surgical techniques, and long-term management. However, bleeding, infection, neurologic events, and right ventricular failure continue to limit broader implementation of LVAD support. Ongoing efforts to optimize management of patients implanted with current devices and parallel development of next-generation devices are likely to further improve outcomes for patients with advanced heart failure.

Postimplant Phosphodiesterase-5 Inhibitor Use in Centrifugal Flow Left Ventricular Assist Devices

OBJECTIVES

This study examined the association between phosphodiesterase-5 inhibitor (PDE-5i) use and outcomes in patients with contemporary centrifugal flow left ventricular assist devices (LVADs).

BACKGROUND

PDE-5i use may affect outcomes in patients with continuous flow LVADs.

METHODS

Patients enrolled in INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support), with HeartMate 3 (n = 4,628) or HeartWare Ventricular Assist Device (HVAD) (n = 2,601) implant were included in the analysis. The mean duration of follow-up was 11.94 ± 8.65 months. PDE-5is were used in 2,173 patients. The primary endpoint was the composite of all-cause mortality, ischemic stroke, and pump thrombosis. Propensity matching and stabilized inverse probability of treatment weights were used to adjust for baseline differences between patients receiving and not receiving PDE-5i. Adjusted Cox proportional hazards analysis was performed for each outcome.

RESULTS

The primary endpoint was lower in the PDE-5i group (adjusted HR: 0.77; 95% CI: 0.69-0.86; P < 0.0001; HeartMate 3: adjusted HR: 0.77; 95% CI: 0.64-0.92; P = 0.0044; HVAD: adjusted HR: 0.76; 95% CI: 0.66-0.88; P = 0.0002). All-cause mortality was lower with PDE-5is (adjusted HR: 0.75; 95% CI: 0.65-0.86; P < 0.0001; HeartMate 3: adjusted HR: 0.70; 95% CI: 0.57-0.86; P = 0.0007; HVAD: adjusted HR: 0.78; 95% CI: 0.65-0.94; P = 0.0098) and fewer ischemic strokes with PDE-5is were observed (adjusted HR: 0.71; 95% CI: 0.56-0.89; P = 0.003; HeartMate 3: adjusted HR: 0.67; 95% CI: 0.45-0.99; P = 0.045; HVAD: adjusted HR: 0.73; 95% CI: 0.56-0.97; P = 0.03). LVAD thrombosis was unchanged with PDE-5is, with overall low event rates observed.

CONCLUSIONS

Postimplant PDE-5i use was associated with lower mortality and ischemic strokes in patients with centrifugal flow LVADs.

Long-term survival on LVAD support: Device complications and end-organ dysfunction limit long-term success

BACKGROUND

Preoperative variables can predict short term left ventricular assist device (LVAD) survival, but predictors of extended survival remain insufficiently characterized.

METHOD

Patients undergoing LVAD implant (2012-2018) in the Intermacs registry were grouped according to time on support: short-term (<1 year, n = 7,483), mid-term (MT, 1-3 years, n = 5,976) and long-term (LT, ≥3 years, n = 3,015). Landmarked hazard analyses (adjusted hazard ratio, HR) were performed to identify correlates of survival after 1 and 3 years of support.

RESULTS

After surviving 1 year of support, additional LVAD survival was less likely in older (HR 1.15 per decade), Caucasian (HR 1.22) and unmarried (HR 1.16) patients (p < 0.05). After 3 years of support, only 3 preoperative characteristics (age, race, and history of bypass surgery, p < 0.05) correlated with extended survival. Postoperative events most negatively influenced achieving LT survival. In those alive at 1 year or 3 years, the occurrence of postoperative renal (creatinine HR MT = 1.09; LT HR = 1.10 per mg/dl) and hepatic dysfunction (AST HR MT = 1.29; LT HR = 1.34 per 100 IU), stroke (MT HR = 1.24; LT HR = 1.42), infection (MT HR = 1.13; LT HR = 1.10), and/or device malfunction (MT HR = 1.22; LT HR = 1.46) reduced extended survival (all p ≤ 0.03).

CONCLUSIONS

Success with LVAD therapy hinges on achieving long term survival in more recipients. After 1 year, extended survival is heavily constrained by the occurrence of adverse events and postoperative end-organ dysfunction. The growth of destination therapy intent mandates that future LVAD studies be designed with follow up sufficient for capturing outcomes beyond 24 months.

Stroke epidemiology and outcomes in the modern era of left ventricular assist devices

The care for the patients with end-stage heart failure has been revolutionized by the introduction of durable left ventricular assist devices, providing a substantial improvement in patient survival and quality of life and an alternative to heart transplantation. The newest devices have lower instances of mechanical dysfunction and associated pump thrombosis. Despite these improvements in complications, the use of continuous flow assist devices is still associated with high rates of thrombotic and hemorrhagic complications, most notably stroke in approximately 10% of continuous flow assist devices patients per year. With the newest HeartMate 3 devices, there have been lower observed rates of stroke, which has in part been achieved by both improvements in pump technology and knowledge of the risk factors for stroke and neurological complications. The therapeutic options available to clinicians to reduce the risk of stroke, including management of hypertension and antithrombotics, will be reviewed in this manuscript.

Inflow cannula position as risk factor for stroke in patients with HeartMate 3 left ventricular assist devices

Background

A relation between the left ventricular assist device inflow cannula (IC) malposition and pump thrombus has been reported. This study aimed to investigate if the pump position, derived from chest X‐rays in HeartMate 3 (HM3) patients, correlates with neurological dysfunction (ND), ischemic stroke (IS), hemorrhagic stroke (HS) and survival.

Methods

This analysis was performed on routinely acquired X‐rays of 42 patients implanted with a HM3 between 2014 and 2017. Device position was quantified in patients with and without ND from frontal and lateral X‐rays characterizing the IC and pump in relation to spine, diaphragm or horizontal line. The primary end‐point was freedom from stroke and survival one‐year after HM3 implantation stratified by pump position.

Results

The analysis of X‐rays, 33.5 (41.0) days postoperative, revealed a significant smaller IC angle of HM3 patients with ND versus no ND (0.1° ± 14.0° vs. 12.9° ± 10.1°, p = 0.005). Additionally, the IC angle in the frontal view, IS: 4.1 (20.9)° versus no IS: 13.8 (7.5)°, p = 0.004 was significantly smaller for HM3 patients with IS. Using receiver operating characteristics derived cut‐off, IC angle <10° provided 75% sensitivity and 100% specificity (C‐statistic = 0.85) for predicting IS. Stratified by IC angle, freedom from IS at 12 months was 100% (>10°) and 60% (<10°) respectively (p = 0.002). No significant differences were found in any end‐point between patients with and without HS. One‐year survival was significantly higher in patients with IC angle >10° versus <10° (100% vs. 71.8%, p = 0.012).

Conclusions

IC malposition derived from standard chest X‐rays serves as a risk factor for ND, IS and worse survival in HM3 patients.

Presence of Intracardiac Thrombus at the Time of Left Ventricular Assist Device Implantation Is Associated With an Increased Risk of Stroke and Death

BACKGROUND

Heart failure predisposes to intracardiac thrombus (ICT) formation. There are limited data on the prevalence and impact of preexisting ICT on postoperative outcomes in left ventricular assist device patients. We examined the risk for stroke and death in this patient population.

METHODS AND RESULTS

We retrospectively studied patients who were implanted with HeartMate (HM) II or HM3 between February 2009 and March 2019. Preoperative transthoracic echocardiograms, intraoperative transesophageal echocardiograms and operative reports were reviewed to identify ICT. There were 525 patients with a left ventricular assist device (median age 60.6 years, 81.8% male, 372 HMII and 151 HM3) included in this analysis. An ICT was identified in 44 patients (8.4%). During the follow-up, 43 patients experienced a stroke and 55 died. After multivariable adjustment, presence of ICT increased the risk for the composite of stroke or death at 6-month (hazard ratio [HR] 1.82, 95% confidence interval [CI] 1.00-3.33, P = .049). Patients with ICT were also at higher risk for stroke (HR 2.45, 95% CI 1.14-5.28, P = .021) and death (HR 2.36, 95% CI 1.17-4.79 P = .016) at 6 months of follow-up.

CONCLUSIONS

The presence of ICT is an independent predictor of stroke and death at 6 months after left ventricular assist device implantation. Additional studies are needed to help risk stratify and optimize the perioperative management of this patient population.

Neurosurgical intervention in children with ventricular assist devices: A single-center case series review

BACKGROUND

The incidence of neurological complications related to ventricular assist devices (VAD) remains high and includes life-threatening conditions such as intracranial hemorrhage or ischemic stroke. Although no definitive management guidelines exist, operative interventions may be required for major neurological injuries.

AIMS

This case series describes the perioperative management of children at a single center who underwent neurosurgical procedures for major intracranial bleeds or ischemic strokes while on VAD support.

METHODS

A database review identified all pediatric VAD patients who underwent a neurosurgical procedure for an intracranial hemorrhage or ischemic stroke from April 2014 to January 2020. Data regarding patient characteristics, preoperative medical management, intraoperative anesthetic management, and postoperative outcomes were collected using retrospective chart review.

RESULTS

Ninety VADs were implanted in 78 patients. Five neurosurgical interventions were performed: four for intracranial hemorrhages and one for an ischemic stroke. All four patients with hemorrhages were receiving anticoagulation at the time of their event and the three patients on warfarin received emergent reversal with prothrombin concentrate complex and vitamin K. Three patients also received pre-procedural platelet transfusions. Two of the five procedures were emergent bedside external ventricular drain placements, and three were surgical operations. All three patients who underwent operative procedures received invasive hemodynamic monitoring and were supported with a combination of inotropes and afterload reduction. One patient required a massive blood product transfusion. The two patients who underwent external ventricular drain placement had no further surgical interventions and died from the severity of their neurological injuries. All three patients who underwent operative procedures survived to transplantation and discharge home.

CONCLUSIONS

Perioperative concerns for the anesthesiologist include VAD hemodynamic management, bleeding, VAD thrombosis, and prevention of secondary brain injury. A systematic, multidisciplinary approach to management is paramount to attain favorable outcomes.

Bleeding in patients with continuous-flow left ventricular assist devices: acquired von Willebrand disease or antithrombotics?

OBJECTIVES

To evaluate the competing pro-haemorrhagic contribution of acquired von Willebrand (vW) disease and antithrombotic therapy in patients implanted with continuous-flow left ventricular assist devices (LVADs).

METHODS

We compared the extent of vW factor (vWf) degradation [vWf antigen (vWf:Ag)] and a decrease of functional activity of large vWf multimers [vWf collagen binding (vWf:CB)] in LVAD patients who did and did not suffer from bleeding. Data were measured pre-implant, at short-term (t1: <3 months) and long-term (t2: >12 months) follow-up. The occurrence of primary bleeding events, as well as bleeding recurrence, was correlated with patient-specific vWf profile and antithrombotic regimen. Indeed, patients were discharged on warfarin (international normalized ratio: 2-2.5) and aspirin, with the latter withhold after a first bleeding episode.

RESULTS

Fifty-three patients were enrolled. The median follow-up was 324 (226-468) days. We recorded 25 primary bleeding events (47% of patients). All primary events occurred in patients on warfarin and aspirin. Both vWf:Ag and vWf:CB decreased significantly post-implant (P = 0.0003 and P < 0.0001), and patients showing pathological vWf:CB/vWf:Ag ratio (<0.7) increased progressively over the time of support (pre-implant = 26%, t1 = 58%, t2 = 74%; P < 0.0001). Of note, activity of large vWf multimers of bleeders was significantly lower at t2 with respect to non-bleeders (vWf:CB: 61 (36-115) vs 100 (68-121), P = 0.04; vWf:CB/vWf:Ag ratio: 0.36 (0.26-0.61) vs 0.58 (0.33-0.96), P = 0.04). Despite these marked differences in the vWf profile, following aspirin discontinuation only 3 patients had bleeding recurrence.

CONCLUSIONS

Aspirin contributes significantly to haemorrhagic events in the background of acquired vW disease; its discontinuation significantly reduces bleeding recurrence.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03255928; ClinicalTrials.gov Identifier: NCT03255928.