A novel intrapericardial pulsatile device for individualized, biventricular circulatory support without direct blood contact.

OBJECTIVE: Due to severely limited donor heart availability, durable mechanical circulatory support remains the only treatment option for many patients with end-stage heart failure. However, treatment complexity persists due to its univentricular support modality and continuous contact with blood. We investigated the function and safety of reBEAT (AdjuCor GmbH), a novel, minimal invasive mechanical circulatory support device that completely avoids blood contact and provides pulsatile, biventricular support. METHODS: For each animal tested, an accurately sized cardiac implant was manufactured from computed tomography scan analyses. The implant consists of a cardiac sleeve with three inflatable cushions, 6 epicardial electrodes and driveline connecting to an electro-pneumatic, extracorporeal portable driver. Continuous epicardial electrocardiogram signal analysis allows for systolic and diastolic synchronization of biventricular mechanical support. In 7 pigs (weight, 50-80 kg), data were analyzed acutely (under beta-blockade, n = 5) and in a 30-day long-term survival model (n = 2). Acquisition of intracardiac pressures and aortic and pulmonary flow data were used to determine left ventricle and right ventricle stroke work and stroke volume, respectively. RESULTS: Each implant was successfully positioned around the ventricles. Automatic algorithm electrocardiogram signal annotations resulted in precise, real-time mechanical support synchronization with each cardiac cycle. Consequently, progressive improvements in cardiac hemodynamic parameters in acute animals were achieved. Long-term survival demonstrated safe device integration, and clear and stable electrocardiogram signal detection over time. CONCLUSIONS: The present study demonstrates biventricular cardiac support with reBEAT. Various demonstrated features are essential for realistic translation into the clinical setting, including safe implantation, anatomical fit, safe device-tissue integration, and real-time electrocardiogram synchronized mechanical support, result in effective device function and long-term safety.

Heart transplantation in children and adults with Down syndrome: A single centre experience.

BACKGROUND: In recent years, rapid advances in cardiac surgery and changes in attitude towards patients with cognitive disability have led to these patients receiving cardiac transplantation. METHOD: This is a retrospective report describing the experience of four patients with Down Syndrome who received heart transplantation in a single institution. RESULTS: Anthracycline-induced cardiomyopathy was the most common cause of heart failure in this group (3/4). Two patients were bridged to transplantation, one by using a combination of extra-corporeal membrane oxygenation and biventricular assist device and the other by using a durable implantable left ventricular assist device. All the four patients are alive with the longest surviving patient 17 years after transplantation. Against strong hypothetical predictions, we observed no propensity for the development of post-transplant infections or lymphoproliferative disorders. CONCLUSION: Down Syndrome should not be the sole contraindication to heart transplantation. The decision for transplantation should be on a case-by-case basis provided adequate social support is in place.

Gender differences in the assessment, decision-making and outcomes for ventricular assist devices and heart transplantation: An analysis from a UK transplant center.

PURPOSE: There are marked gender differences in all etiologies of advanced heart failure. We sought to determine whether there is evidence of gender-specific decision making for transplant assessments, and how gender effects outcomes. METHODS: Retrospective analysis of adult heart transplant assessments at a single UK center between April 2015 and March 2020. RESULTS: Females were 32% of referrals (N = 137 females, 285 males), with marked differences between diagnoses - 11% ischemic and 43% of adult congenital. Females were younger, shorter, weighed less, and had lower pulmonary pressures. Females were much less likely to receive a ventricular assist device (13%). Blood type "O" females were relatively more likely compared to males to receive a transplant (45%). Comparing males and females who received a ventricular assist device, both had similar levels of high pulmonary pressures, indicating consistent decision-making based on hemodynamics to implant a device. Overall survival was better for females (in noncongenital patients), and this was due to female patients who were not accepted for transplant or a ventricular assist device being more often "too well for transplant," rather than in males when they were more often "unsuitable." CONCLUSIONS: Marked gender differences exist at all stages of the heart transplant assessment pathway. Appropriate decision-making based on clinical grounds is shown with less transplants in male blood type "O"s and hemodynamic criteria for ventricular assist device implantation in both genders. Further studies are needed to determine if there is a wider community bias in advanced heart failure treatments for females.

Ventricular assist devices in transposition and failing systemic right ventricle: role of tricuspid valve replacement.

OBJECTIVES: Ventricular assist device (VAD) for systemic right ventricular (RV) failure patients post-atrial switch, for transposition of the great arteries (TGA), and those with congenitally corrected TGA has proven useful to reduce transpulmonary gradient and bridge-to-transplantation. The purpose of this study is to describe our experience of VAD in systemic RV failure and our move towards concomitant tricuspid valve replacement (TVR). METHODS: This is a single-centre retrospective study of consecutive adult patients receiving HeartWare VAD for systemic RV failure between 2010 and 2019. From 2017, concomitant TVR was performed routinely. Demographic, clinical variables and echocardiographic and haemodynamic measurements pre- and post-VAD implantation were recorded. Complications on support, heart transplantation and survival rates were described. RESULTS: Eighteen patients underwent VAD implantation. Moderate or severe systemic tricuspid regurgitation was present in 83.3% of patients, and subpulmonic left ventricular impairment in 88.9%. One-year survival was 72.2%. VAD implantation was technically feasible and successful in all but one. Post-VAD, transpulmonary gradient fell from 16 (15-22) to 10 (7-13) mmHg (P = 0.01). Patients with TVR (n = 6) also demonstrated a reduction in mean pulmonary and wedge pressures. Furthermore, subpulmonic left ventricular end-diastolic dimension (44.3 vs 39.6 mm; P = 0.03) and function improved in this group. After 1 year of support, 72.2% of patients were suitable for transplantation. CONCLUSIONS: VAD is an effective strategy as bridge-to-candidacy and bridge-to-transplantation in patients with end-stage systemic RV failure. Concomitant TVR at the time of implant is associated with better early haemodynamic and echocardiographic results post-VAD.

Does infection predispose to thrombosis during long-term ventricular assist device support?

BACKGROUND: Infections and thrombotic events remain life-threatening complications in patients with ventricular assist devices (VAD). METHODS: We describe the relationship between both events in our cohort of patients (n = 220) supported with the HeartWare VAD (HVAD). This is a retrospective analysis of patients undergoing HVAD implantation between July 2009 and March 2019 at the Freeman Hospital, Newcastle upon Tyne, United Kingdom. RESULTS: Infection was the most common adverse event in HVAD patients, with 125 patients (56.8%) experiencing ≥ one infection (n = 168, 0.33 event per person year (EPPY)), followed by pump thrombosis (PT) in 61 patients (27.7%, 0.16 EPPY). VAD-specific infections were the largest group of infections. Of the 125 patients who had an infection, 66 (53%) had a thrombotic event. Both thrombotic events and infections were related to the duration of support, though there was only limited evidence that infections predispose to thrombosis. Those with higher than median levels of C-reactive protein during the infection were more likely to have an ischaemic stroke (IS) (34.5% vs 16.7%, p = .03), though not PT or a combined thrombotic event (CTE: first PT or IS). However, in multivariate analysis, there was no significant effect of infection predisposing to CTE. CONCLUSIONS: Infection and thrombotic events are significant adverse events related to the duration of support in patients receiving HVADs. Infections do not clearly predispose to thrombotic events.

Outcomes of Durable Mechanical Circulatory Support in Myocarditis: Analysis of the International Society for Heart and Lung Transplantation Registry for Mechanically Assisted Circulatory Support Registry.

Myocarditis can be refractory to medical therapy and require durable mechanical circulatory support (MCS). The characteristics and outcomes of these patients are not known. We identified all patients with clinically-diagnosed or pathology-proven myocarditis who underwent mechanical circulatory support in the International Society for Heart and Lung Transplantation Registry for Mechanically Assisted Circulatory Support registry (2013-2016). The characteristics and outcomes of these patients were compared to those of patients with nonischemic cardiomyopathy (NICM). Out of 14,062 patients in the registry, 180 (1.2%) had myocarditis and 6,602 (46.9%) had NICM. Among patients with myocarditis, duration of heart failure was <1 month in 22%, 1-12 months in 22.6%, and >1 year in 55.4%. Compared with NICM, patients with myocarditis were younger (45 vs. 52 years, P < 0.001) and were more often implanted with Interagency Registry for Mechanically Assisted Circulatory Support profile 1 (30% vs. 15%, P < 0.001). Biventricular mechanical support (biventricular ventricular assist device [BIVAD] or total artificial heart) was implanted more frequently in myocarditis (18% vs. 6.7%, P < 0.001). Overall postimplant survival was not different between myocarditis and NICM (left ventricular assist device: P = 0.27, BIVAD: P = 0.50). The proportion of myocarditis patients that have recovered by 12 months postimplant was significantly higher in myocarditis compared to that of NICM (5% vs. 1.7%, P = 0.0003). Adverse events (bleeding, infection, and neurologic dysfunction) were all lower in the myocarditis than NICM. In conclusion, although myocarditis patients who receive durable MCS are sicker preoperatively with higher needs for biventricular MCS, their overall MCS survival is noninferior to NICM. Patients who received MCS for myocarditis are more likely than NICM to have MCS explanted due to recovery, however, the absolute rates of recovery were low.

LVAD decommissioning for myocardial recovery: Long-term ventricular remodeling and adverse events.

BACKGROUND: Left ventricular assist devices (LVADs) mechanically unload the heart and coupled with neurohormonal therapy can promote reverse cardiac remodeling and myocardial recovery. Minimally invasive LVAD decommissioning with the device left in place has been reported to be safe over short-term follow-up. Whether device retention reduces long-term safety, or sustainability of recovery is unknown. METHODS: This is a dual-center retrospective analysis of patients who had achieved responder status (left ventricular ejection fraction, LVEF ≥40% and left ventricular internal diastolic diameter, LVIDd ≤6.0 cm) and underwent elective LVAD decommissioning for myocardial recovery from May 2010 to January 2020. All patients had outflow graft closure and driveline resection with the LVAD left in place. Emergent LVAD decommissioning for an infection or device thrombosis was excluded. Patients were followed with serial echocardiography for up to 3-years. The primary clinical outcome was survival free of heart failure hospitalization, LVAD reimplantation, or transplant. RESULTS: During the study period 515 patients received an LVAD and 29 (5.6%) achieved myocardial recovery, 12 patients underwent total device explantation or urgent device decommissioning, 17 patients underwent elective LVAD decommissioning, and were included in the analysis. Median age of patients at LVAD implantation was 42 years (interquartile range, IQR: 25-54 years), all had a nonischemic cardiomyopathy, and 5 (29%) were female. At LVAD implantation, median LVEF was 10% (IQR: 5%-15%), and LVIDd 6.6 cm (IQR: 5.8-7.1 cm). There were 11 hydrodynamically levitated centrifugal-flow (65%), and 6 axial-flow LVADs (35%). The median duration of LVAD support before decommissioning was 28.7 months (range 13.5-36.2 months). As compared to the turndown study parameters, 1-month post-decommissioning, median LVEF decreased from 55% to 48% (p = 0.03), and LVIDd increased from 4.8 cm to 5.2 cm (p = 0.10). There was gradual remodeling until 6 months, after which there was no statistical difference on follow-up through 3-years (LVEF 42%, LVIDd 5.6 cm). Recurrent infections affected 41% of patients leading to 3 deaths and 1 complete device explant. Recurrent HF occurred in 1 patient who required a transplant. Probability of survival free of HF, LVAD, or transplant was 94% at 1-year, and 78% at 3-years. CONCLUSIONS: LVAD decommissioning for myocardial recovery was associated with excellent long-term survival free from recurrent heart failure and preservation of ventricular size and function up to 3-years. Reducing the risk of recurrent infections, remains an important therapeutic goal for this management strategy.

Cost-effectiveness of left ventricular assist devices as destination therapy in the United Kingdom.

AIMS: Continuous-flow left ventricular assist devices (LVADs) as destination therapy (DT) are a recommended treatment by National Institute for Health and Care Excellence England for end-stage heart failure patients ineligible for cardiac transplantation. Despite the fact that DT is frequently used as an LVAD indication across other major European countries and the United States, with consistent improvements in quality-of-life and longevity, National Health Service (NHS) England does not currently fund DT, mainly due to concerns over cost-effectiveness. On the basis of the recently published ENDURANCE Supplemental Trial studying DT patients, we assessed for the first time the cost-effectiveness of DT LVADs compared with medical management (MM) in the NHS England. METHODS AND RESULTS: We developed a Markov multiple-state economic model using NHS cost data. LVAD survival and adverse event rates were derived from the ENDURANCE Supplemental Trial. MM survival was based on Seattle Heart Failure Model estimates in the absence of contemporary clinical trials for this population. Incremental cost-effectiveness ratios (ICERs) were calculated over a lifetime horizon. A discount rate of 3.5% per year was applied to costs and benefits. Deterministic ICER was £46 207 per quality-adjusted life year (QALY). Costs and utilities were £204 022 and 3.27 QALYs for the LVAD arm vs. £77 790 and 0.54 QALYs for the MM arm. Sensitivity analyses confirmed robustness of the primary analysis. CONCLUSIONS: The implantation of the HeartWare™ HVAD™ System in patients ineligible for cardiac transplantation as DT is a cost-effective therapy in the NHS England healthcare system under the end-of-life willingness-to-pay threshold of £50 000/QALY, which applies for VAD patients.

Markers of Right Ventricular Dysfunction Predict Maximal Exercise Capacity After Left Ventricular Assist Device Implantation.

Although left ventricular assist device (LVAD) improves functional capacity, on average LVAD patients are unable to achieve the aerobic capacity of normal healthy subjects or mild heart failure patients. The aim of this study was to examine if markers of right ventricular (RV) function influence maximal exercise capacity. This was a single-center prospective study that enrolled 20 consecutive HeartWare ventricular assist device patients who were admitted at the Freeman Hospital (Newcastle upon Tyne, United Kingdom) for a heart transplant assessment from August 2017 to October 2018. Mean peak oxygen consumption (Peak VO2) was 14.0 ± 5.0 ml/kg/min, and mean peak age and gender-adjusted percent predicted oxygen consumption (%VO2) was 40.0% ± 11.5%. Patients were subdivided into two groups based on the median peak VO2, so each group consisted of 10 patients (50%). Right-sided and pulmonary pressures were consistently higher in the group with poorer exercise tolerance. Patients with poor exercise tolerance (peak VO2 below the median) had higher right atrial pressures at rest (10.6 ± 6.4 vs. 4.3 mmHg ± 3.2; p = 0.02) and the increase with passive leg raising was significantly greater than those with preserved exercise tolerance (peak VO2 above the median). Patients with poor functional capacity also had greater RV dimensions (4.4 cm ± 0.5 vs. 3.7 cm ± 0.5; p = 0.02) and a higher incidence of significant tricuspid regurgitation (moderate or severe tricuspid regurgitation in five patients in the poor exercise capacity group vs. none in the preserved exercise capacity group; p = 0.03). In conclusion, echocardiographic and hemodynamic markers of RV dysfunction discriminate between preserved and nonpreserved exercise capacity in HeartWare ventricular assist device patients.

Using existing technology better: Improving outcomes with the HeartWare left ventricular assist device.

BACKGROUND: The HeartWare left ventricular assist device has been in use for over 12 years. We sought to determine how outcomes at our centre have improved over time. METHODS: Review of electronic hospital records at the Freeman Hospital, Newcastle upon Tyne, United Kingdom. RESULTS: A total of 255 first time adult implants were divided into 2 eras: Era 1: 2009-2015 (N = 154) and Era 2: 2016-2020 (N = 101). We prospectively aimed to avoid higher risk Intermacs Classifications in Era 2, which resulted in significant changes in Intermacs class to lower risk in Era 2 (P < 0.001). There was a significant improvement in survival in Era 2, with 1 year survival increasing from 70 to 80% (P < 0.05). This was particularly associated with lower 30 day mortality in Era 2 (1.7 ± 2.3 vs 15.5 ± 7%, P < 0.005). This was associated with better right ventricular function in Era 2, and there was a trend to more temporary right ventricular assist devices used in Era 2 (28 ± 13 vs 12 ± 14%, P = 0.06). Deaths from intracranial haemorrhage, sepsis and right heart failure were unchanged between eras, though there was a trend towards less deaths in Era 2 from combined thromboses deaths (stroke and device thrombosis; 3.3 ± 5.4 vs 11.1 ± 7.4%, P = 0.07). CONCLUSIONS: Better patient selection in association with more use of temporary right ventricular assist support has resulted in a significant improvement in survival. Intracranial haemorrhage, sepsis and right heart failure remain significant problems.

HeartWare Explant After Recovery 6 Years After Implant in a 3-Year-Old Child: Has the Game Changed?

The use of continuous-flow mechanical circulatory support in preschool children remains anecdotal. This case report describes the sequel to the implantation with a HeartWare HVAD system (Medtronic, Minneapolis, MN) in a 3-year old child. A 3-year-old boy with myocarditis-related cardiomyopathy underwent implantation with a HeartWare device. After an uncomplicated postoperative course, the patient was discharged home. Serial echocardiography showed progressive left ventricular recovery. After 6 months, the device was decommissioned, and the outflow graft was tied off. Six years after insertion, the device was explanted uneventfully. The HeartWare ventricular assist device offers viable long-term mechanical circulatory support in selected children that results in sustainable care and good quality of life.

Validity of Hemodynamic Monitoring Using Inert Gas Rebreathing Method in Patients With Chronic Heart Failure and Those Implanted With a Left Ventricular Assist Device.

OBJECTIVE: The present study assessed agreement between resting cardiac output estimated by inert gas rebreathing (IGR) and thermodilution methods in patients with heart failure and those implanted with a left ventricular assist device (LVAD). METHODS AND RESULTS: Hemodynamic measurements were obtained in 42 patients, 22 with chronic heart failure and 20 with implanted continuous flow LVAD (34 males, aged 50 ± 11 years). Measurements were performed at rest using thermodilution and IGR methods. Cardiac output derived by thermodilution and IGR were not significantly different in LVAD (4.4 ± 0.9 L/min vs 4.7 ± 0.8 L/min, P = .27) or patients with heart failure (4.4 ± 1.4 L/min vs 4.5 ± 1.3 L/min, P = .75). There was a strong relationship between thermodilution and IGR cardiac index (r = 0.81, P = .001) and stroke volume index (r = 0.75, P = .001). Bland-Altman analysis showed acceptable limits of agreement for cardiac index derived by thermodilution and IGR, namely, the mean difference (lower and upper limits of agreement) for patients with heart failure -0.002 L/min/m2 (-0.65 to 0.66 L/min/m2), and -0.14 L/min/m2 (-0.78 to 0.49 L/min/m2) for patients with LVAD. CONCLUSIONS: IGR is a valid method for estimating cardiac output and should be used in clinical practice to complement the evaluation and management of chronic heart failure and patients with an LVAD.

Long-Term Survival of Patients With Advanced Heart Failure Receiving an Left Ventricular Assist Device Intended as a Bridge to Transplantation: The Registry to Evaluate the HeartWare Left Ventricular Assist System.

BACKGROUND: The paucity of available hearts for transplantation means that more patients remain on durable left ventricular support for longer periods of time. The Registry to Evaluate the HeartWare Left Ventricular Assist System was an investigator-initiated multicenter, prospective, single-arm database established to collect post-Conformité Européene mark clinical information on patients receiving the HeartWare ventricular assist device system as a bridge to transplantation. This registry represents the longest multicenter follow-up of primary left ventricular assist device outcomes. METHODS: Data were collected on 254 commercial implants performed between February 2009 and March 2012 from 9 centers in Europe (7) and Australia (2). Patients were followed to device explant, heart transplantation, or death. The outcomes of patients through July/August 2018 were analyzed. Summary statistics were used to describe patient demographics, adverse events, length of support, and outcomes for this extended-term cohort. RESULTS: A total of 122 patients were on support for >2 years, and 34 patients were on support for >5 years. Twenty nine patients are still alive on support (support ranging from 1213 to 3396 days), and 23 of those are on their original HeartWare ventricular assist device system. Kaplan-Meier survival through 7 years was 51%. Through 6 years, freedom from any stroke was 82%, while freedom from severely disabling stroke was 89%. CONCLUSIONS: Low rates of heart transplant now require longer periods of left ventricular assist device support in patients. This analysis demonstrates that long-term support using a HeartWare ventricular assist device system offers survival of 51% through 7 years.

Neutrophil to Lymphocyte Ratio Is Related to Thrombotic Complications and Survival in Continuous Flow Left Ventricular Assist Devices.

Left ventricular assist devices (LVADs) have become an established treatment for advanced heart failure, although with long-term support these patients are potentially exposed to serious complications. Our purpose was to assess the role of the neutrophil to lymphocyte ratio (NLR) in LVAD complications and to evaluate if higher values of NLR after 4-6 months on LVAD support (NLR 4_6m) are associated with worse prognosis. All consecutive patients who received a HeartWare LVAD (N = 188, age 50 ± 13 years), as bridge to transplant from December 2009 to January 2018 were included. Neutrophil to lymphocyte ratio was recorded pre-LVAD, post-LVAD, after 4-6 months on support and in case of a first adverse event to occur after the 4-6 months NLR was recorded. Median NLR values were pre-LVAD 4.26 (interquartile range [IQR], 3.1-6.9), at 1 day postoperative 11.6 (IQR, 8.3-16.6), and NLR 4_6m 4.4 (IQR, 3.0-6.4) (p < 0.001). Neutrophil to lymphocyte ratio increased significantly when patients had an infection, stroke, or pump thrombosis, as compared with the NLR 4_6m (all p < 0.05). Patients with NLR 4_6m ≥ median had higher rates of stroke and mortality. Survival time was shorter among patients with NLR 4_6m ≥ 4.4 (log-rank test p = 0.006). Neutrophil to lymphocyte ratio 4_6m was found to be predictive of increased mortality (area under the curve of 0.62, p = 0.007). After multivariate analysis, NLR 4_6m remained independently associated with increased mortality (hazard ratio [HR] 1.67; 95% confidence interval [CI], 1.03-2.7; p = 0.037). Neutrophil to lymphocyte ratio 4_6m values significantly increase in association with adverse events on LVAD support and are independently associated with mortality. This association suggests presence of inflammation adversely affects LVAD outcomes.

Effect of Preoperative Tricuspid and/or Mitral Regurgitation on Development of Late Right-Sided Heart Failure After Insertion of the HeartWare Left Ventricular Assist Device.

Right-sided heart failure (RHF) after left ventricular assist device implantation is a significant cause of morbidity and mortality. Although multiple predictors of early RHF have been described, information on late RHF is scarce. The aim of this study was to identify predictors of late RHF in left ventricular assist device patients. A retrospective analysis of all adult patients who underwent HeartWare-ventricular assist device implantation as a bridge to transplantation in a single-centre was performed. Late RHF was defined as RHF requiring rehospitalization after 30 days of implantation. A total of 16 (10.3%) patients from 156 implantations developed late RHF. Median time to late RHF onset was 182.5 (interquartile range 105 to 618) days. Patients developing late RHF were older at surgery. A significantly higher rate of moderate or severe tricuspid regurgitation before implantation was found in patients presenting with late RHF (81.2% vs 33.5%; p <0.001). Several echocardiographic parameters at discharge postimplant, such as significant mitral regurgitation, demonstrated a strong association with late RHF. A multivariate Cox regression analysis revealed that significant preoperative tricuspid regurgitation was the strongest predictor of late RHF (hazard ratio 5.50, 95% confidence interval [1.34 to 22.58]; p = 0.02). Significant mitral regurgitation postimplantation and older age also significantly predicted late RHF. In conclusion, preoperative significant tricuspid regurgitation and mitral regurgitation after implantation predict the occurrence of late RHF.

Left Ventricular Filling Pressures Contribute to Exercise Limitation in Patients with Continuous Flow Left Ventricular Assist Devices.

We sought to determine hemodynamic mechanisms of exercise intolerance in a group of patients with the HeartWare ventricular assist device (VAD) compared to a group of heart failure patients. Twenty VAD and 22 heart failure patients underwent symptom-limited active straight leg raising exercise during right heart catheterization with thermodilution (TD), and upright cycling cardiopulmonary stress testing with cardiac output measurement by inert gas rebreathing (IGR) method. The TD and IGR exercise cardiac indexes were higher in VAD compared with heart failure group (both P < 0.05), although there was only a borderline increase in peak exercise oxygen consumption (VO2) (P = 0.06). Baseline and exercise right heart catheterization pressures were not significantly different between the two groups. The only significant independent predictors of peak VO2 in the heart failure group were exercise heart rate and cardiac index (both P < 0.05). In contrast, for the VAD group only, resting pulmonary arterial wedge and pulmonary arterial mean pressures were independently related to peak VO2 (both P < 0.05). Thus, in heart failure, exercise cardiac index is an important limitation to exercise capacity, and VADs increase exercise cardiac index. However, in VAD patients, this only produces limited benefits as increased pulmonary and pulmonary wedge pressures limit increases in exercise capacity.

Initial conservative management strategy of HeartWare left ventricular assist device thrombosis with intravenous heparin or bivalirudin.

INTRODUCTION AND OBJECTIVES: Pump thrombosis is a serious left ventricular assist device complication, though there are no guidelines regarding its treatment. The main aim of this study was to describe a strategy of intravenous anticoagulation as the initial treatment in these patients and then to compare intravenous heparin with bivalirudin. METHODS: All consecutive patients who received a HeartWare left ventricular assist device from July 2009 to March 2019 were retrospectively analysed. Patients developing a pump thrombosis were selected, and treatment, outcomes and complications were recorded. RESULTS: During this period of time (116 months), 220 patients underwent HeartWare left ventricular assist device implantation and 57 developed pump thrombosis, with an incidence rate of first pump thrombosis of 0.17 events per patient-year of support (incidence rate of all episodes of pump thrombosis: 0.30 events per patient-year of support). All the patients were initially treated medically, predominantly with either intravenous heparin (n = 26) or bivalirudin (n = 16). Patients treated with bivalirudin during the first pump thrombosis episode had less subsequent re-thrombosis episodes (18.7% vs 57.7%, p < 0.05). In addition, percentage time in therapeutic range was greater for bivalirudin compared with heparin (68.5% ± 16.9% vs 37.4% ± 31.0%, p < 0.01). During the first pump thrombosis episode, 26.3% of the patients needed surgery (left ventricular assist device exchange (n = 8), transplant (n = 6) or decommissioning (n = 1)). The overall survival at 1 year was 61.4%, and there was no significant difference in survival. CONCLUSION: Left ventricular assist device thrombosis is a serious life-threatening complication; hence, we propose an initial conservative management of pump thrombosis with enhanced intravenous anticoagulation with either intravenous heparin or bivalirudin, with surgery reserved for refractory cases.

The role of exercise hemodynamics in assessing patients with chronic heart failure and left ventricular assist devices.

Introduction: Chronic heart failure is characterized by reduced exercise capacity. Invasive exercise hemodynamics are not routinely performed unless patients undergo transplant or left ventricular assist devices (LVAD) assessment, though now with readily available noninvasive devices, exercise hemodynamics are easily obtained. Our contention is that this is a valuable opportunity to acquire a more accurate measure of cardiac status in heart failure. Exercise hemodynamic measures such as cardiac power output can be carried out cheaply and effectively. Recent studies have highlighted the added value of exercise hemodynamics in prognostication of heart failure, and their role in assessing myocardial recovery in LVADs. Areas covered: In this review, we explore the literature available on Medline until 2019 focusing on resting and exercise hemodynamics alongside the methods of assessment (invasive and noninvasive) in heart failure with reduced ejection fraction and patients with implanted LVADs. Expert opinion: Hemodynamics measured both at rest and exercise are expected to play a significant role in the work up of transplant and LVAD patients. Furthermore, there is the potential to utilize noninvasive assessment in a complimentary fashion to support patient selection and improve the monitoring of response to treatment across the full cohort of heart failure patients.