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 centre

PURPOSE

There are marked gender differences in all aetiologies 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 centre between April 2015 and March 2020.

RESULTS

Females were 32% of referrals (N = 137 females, 285 males), with marked differences between diagnoses - 11% ischaemics 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 haemodynamics to implant a device. Overall survival was better for females (in non congenital 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 haemodynamic criteria for ventricular assist device implantation in both genders. Further studies are need to determine if there is a wider community bias in advanced heart failure treatments for females. This article is protected by copyright. All rights reserved.

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 CRP during the infection were more likely to have an ischaemic stroke (IS) (34.5% vs 16.7%, p=0.03), 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.

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.

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.

Durable left ventricular assist device support as a bridge to heart transplant candidacy†

OBJECTIVES

Left ventricular assist devices are funded in the UK exclusively as a bridge to transplant (BTT). However, patients who potentially could receive a transplant may develop reversible contraindications to transplant. Bridge to candidacy (BTC) has sometimes been controversial, given the uncertain clinical efficacy of BTC and the risk that reimbursement could be denied. We analysed the UK ventricular assist device database to understand how common BTC was and to assess patient survival rates and incidences of transplants.

METHODS

We identified BTC implants in patients with pulmonary hypertension, chronic kidney disease and obesity using the UK guidelines for heart transplants.

RESULTS

A total of 306 of 540 patients had complete data and 157 were identified as BTC (51%). Overall, there was no difference in survival rates between patients designated as BTC and those designated at BTT (71.9 vs 72.9% at 1 year, respectively; P = 0.82). However, the survival rate was lower at all time points in those with an estimated glomerular filtration rate (eGFR) <40 and in patients with a body mass index (BMI) >32 up to 1-year postimplant. There were no significant differences in the incidence of transplant between patients who were BTC and BTT or for any subgroup up to 5 years. However, we noted a diverging trend towards a lower cumulative incidence of transplant for patients with a BMI >32.

CONCLUSIONS

BTC is common in the UK and appears clinically effective, given that the survival rates and the incidence of transplants were comparable with those for BTT. Patients with a high BMI have a worse survival rate through to 1 year and a trend for a lower incidence of a transplant. Patients with a low eGFR also have a worse survival rate, but a similar proportion received transplants.

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.

P1672Late right heart failure predictors after left ventricular assist device implantation

Background

Right heart failure (RHF) after left ventricular assist device (LVAD) implantation is a significant cause of morbidity and mortality. While 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 LVAD patients.

Methods

A retrospective analysis of all adult patients who underwent HeartWare-VAD implantation for ischemic heart disease or non-ischemic dilated cardiomyopathy in a single centre was performed. Late RHF was defined as RHF requiring hospitalization and medical treatment after 30 days of LVAD implantation.

Results

A total of 16 (10.3%) patients from 156 implantations developed late RHF. Patients developing late RHF were older at time of surgery, 56.7±6.9 vs 49.5±12.5 years; p<0.01. 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 post-implant, such as mitral regurgitation, demonstrated a strong association with late RHF. A multivariate Cox proportional-hazards regression analysis (table 1) revealed that significant pre-operative tricuspid regurgitation (moderate or severe) was the strongest predictor of late RHF development after LVAD surgery (HR 5.50, 95% CI [1.34–22.58]; p=0.02). Significant mitral regurgitation post-implantation and older age also predicted late RHF development.

Multivariate Cox proportional-hazards analysis for late right heart failure Variable Hazard ratio 95% confidence interval P-value Tricuspid regurgitation- moderate or severe 5.50 1.34–22.58 0.02 Mitral regurgitation (discharge)- moderate or severe 3.54 1.14–11.02 0.03 Age 1.07 1.01–1.14 0.03 Right ventricular basal diameter 1.14 0.43–3.03 0.79 Right ventricular fractional area change 0.98 0.87–1.10 0.79 Multivariate analysis showing predictors of late right heart failure according to a multivariate model.

Late RHF according to TR severity

Conclusions

Pre-operative significant tricuspid regurgitation and mitral regurgitation after implantation predict the occurrence of late RHF. Prospective studies are needed to determine whether tricuspid valve interventions may reduce late RHF.

P5418Anticoagulation management of heartware left ventricular assist device thrombosis: comparison of heparin and bivalirudin

Introduction and purpose

Pump thrombosis (PT) is a serious left ventricular assist device (LVAD) complication, though there are no guidelines regarding its treatment. We have adopted a strategy of intravenous anticoagulation as the initial treatment strategy in these patients.

Methods

All consecutive patients who received a HeartWare LVAD from July-2009 to January-2018 were retrospectively analyzed. Patients developing a PT were selected, and treatment, outcomes and complications were recorded.

Results

197 patients underwent HVAD, and 49 developed PT. All the patients were initially treated medically, though during the first PT 26.5% of the patients needed surgery [VAD exchange (n=6), transplant (n=6), or decommissioning (n=1)]. The overall survival at 1 year was 63.3%. Patients were treated predominantly with either intravenous heparin or bivalirudin. There were no significant differences neither in complications nor in survival between the 2 treatments (Figure 1); however, patients treated with bivalirudin during the first PT episode had less subsequent re-thrombosis episodes (18.2% vs 57.7%, p<0.05), and percentage time in therapeutic range was greater for bivalirudin compared with heparin (59.7±4.2 vs 36.3±7.1, p<0.01). Nevertheless, time to normalisation of LDH levels with bivalirudin was longer than with heparin (17.2±2.6 vs 10.2±4.5 days, p<0.01) (Table 1).

Table 1. Comparison of baseline characteristics and outcomes between Heparin and Bivalirudin Heparin (n=26) Bivalirudin (n=11) p-value Male, gender n (%) 20 (76.9) 9 (81.8) 1.00 Age when implant (years) 48±11.8 49.8±11.4 0.67 AF n (%) 9 (34.6) 6 (54.5) 0.50 Diagnosis:   Dilated cardiomyopathy n (%) 13 (50) 7 (63.6)   Ischemic heart disease n (%) 12 (46.2) 3 (27.3)   Congenital heart disease n (%) 1 (3.8) 1 (9) 0.50 Thrombolysis (+ alteplase) n (%) 19 (73.1) 4 (36.4) 0.08 Treatment duration (days) 11.5±7.2 15.3±6.5 0.15 % Time in range 36.3±7.1 59.7±4.2 0.009 Hospitalisation (days) 19.1±16.4 31.9±18.2 0.06 Complications:   Ischemic Stroke n (%) 2 (7.7) 4 (36.4) 0.09   Intracraneal bleeding n (%) 2 (7.7) 0 (0) 0.88   Gastrointestinal bleeding n (%) 1 (3.8) 0 (0) 1.00   Serious bleeding n (%) 5 (19.2) 0 (0) 0.29   Any bleeding n (%) 7 (26.9) 2 (18.2) 0.88 LDH   Baseline 271.7±79.3 221.6±41.3 0.10   Admision 727.8±448.2 517.5±171.3 0.21   Maximum 827.1±424.7 1217.6±1004 0.03   Discharge 334.9±135.9 308.6±111.8 0.70   Time to normalisation (days) 10.2±4.5 17.2±2.6 0.004 Outcomes:   Transplant (total) n (%) 7 (26.9) 2 (18.2) 0.88   VAD Exchange (total) n (%) 8 (30.8) 4 (36.4) 1.00   Mortality at 2 years n (%) 15 (57.7) 5 (45.4) 0.831 Rethrombosis:   Rethrombosis n (%) 15 (57.7) 2 (18.2) 0.03   Number of episodes of rethrombosis 0.15     +1 n=6 n=1     +2 n=4 n=1     +3 n=4 n=0     +4 n=1 n=0

Figure 1

Conclusion

VAD thrombosis is a serious life threatening complication, though an initial strategy with enhanced intravenous anticoagulation is an acceptable strategy with either intravenous heparin or bivalirudin.

Acknowledgement/Funding

N. Bouzas-Cruz would like to thank the Spanish Society of Cardiology (Sociedad Española de Cardiología), for her research grant and fellowship.

P1677Elevation of right-sided pressures and right ventricular echocardiographic parameters: predictors of Exercise Limitation in Patients with Implanted Continuous Flow Left Ventricular Assist Devices

Introduction

Left Ventricular Assist Devices (LVAD) improve survival and functional capacity in patients with advanced heart failure (HF). However, there are potential complications.

Purpose

We sought to determine parameters of exercise intolerance in a group of patients with the HeartWare LVAD (HVAD) compared to a group of HF patients.

Methods

This was a single-centre parallel prospective group-study. Briefly, echocardiograms, right heart catheterisation (RHC) and cardiopulmonary exercise tests were performed in forty-two patients admitted for a heart transplant assessment between August2017 and October2018.Of them 20 belonged to the HVAD group and 22 to the HF group.

Results

In our study, HVAD patients had a better exercise capacity than HF patients, although no significant differences were noted (14.0±5.0 ml/kg/min vs 11.3±3.9 ml/kg/min, p=0.06). To determine exercise tolerance, both HVAD and HF groups were subdivided into 2 groups based on the median peak exercise oxygen consumption (peakVO2) for that group. The table shows the comparison between preserved and non-preserved exercise tolerance in HF and HVADpatients. First of all, in the HVADgroup, all resting RHC pressures were significantly lower in the preserved exercise capacity group. However, in HFpatients there were no statistically significant differences between both subgroups in right-sided pressures, but Thermodilution exercise-induced change in cardiac output (ΔCO) and cardiac index (ΔCI) was significantly higher in the patients with preserved exercise tolerance. Secondly, in the HVADgroup the right ventricle was significantly larger in the reduced exercise tolerance subgroup. Moreover, patients with lower peak VO2 had more significant tricuspid regurgitation. Nevertheless, in HFpatients none of the echocardiographic parameters were related to the exercise capacity.

HF HVAD > Median Peak V02 < Median Peak V02 p > Median Peak V02 < Median Peak V02 p Thermodilution CO, l/min: • Rest 4.3±1.0 4.4±1.8 0.82 4.8±0.8 4.2±1.2 0.21 • Exercise 5.6±1.7 4.8±1.8 0.36 7.1±3.2 4.8±0.8 0.05 • ΔCO 1.26±1.0 0.26±0.7 0.02 2.2±2.5 0.4±0.7 0.05 Right Atrium pressure, mmHg 7.0±4.5 6.8±4.10 0.92 4.3±3.2 10.6±6.40 0.02 Mean Pulmonary Artery pressure, mmHg 26.4±12.6 26.5±10.9 0.97 16.8±5.4 30.5±12.5 0.01 Tricuspid Regurgitation, n (%): • None 1 (9) 1 (9) 1 (12) 0 (0) • Mild 7 (64) 8 (73) 7 (88) 4 (44) • Moderate 2 (18) 0 (0) 0 (0) 4 (44) • Severe 1 (9) 2 (18) 0.36 0 (0) 1 (12) 0.03 Right Ventricle Basal Diastolic Diameter, cm 4.0±1.0 4.1±1.0 0.83 3.7±0.5 4.4±0.5 0.02

Conclusion

Right-sided parameters in the echocardiogram and RHC pressures discriminate between preserved and non-preserved exercise capacity in HVADpatients, but not in HFpatients. In these last patients only ΔCO and ΔCI were statistically correlated with peak exercise oxygen consumption

Acknowledgement/Funding

N. Bouzas-Cruz would like to thank the Spanish Society of Cardiology (Sociedad Española de Cardiología), for her research grant and fellowship

Epidemiology of infection in mechanical circulatory support: A global analysis from the ISHLT Mechanically Assisted Circulatory Support Registry

BACKGROUND

Despite advances in device technology and treatment strategies, infection remains a major cause of adverse events (AEs) in mechanical circulatory support (MCS) patients. To characterize the epidemiology of MCS infection, we examined the type, location, and timing of infection in the International Society for Heart and Lung Transplantation Registry (ISHLT) for Mechanically Assisted Circulatory Support (IMACS) over 3 years, 2013 to 2015.

METHODS

Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definitions were used to categorize AE infections occurring in MCS patients within IMACS. The IMACS infection variables were mapped to ISHLT definitions for infection where feasible. Three categories of MCS infection were defined as ventricular assist device (VAD) specific, VAD related, and non-VAD.

RESULTS

There were 10,171 patients enrolled from January 2013 through December 2015. Infection was the most common AE, with 3,788 patients (37%) experiencing ≥ 1 infection, and 6,758 AE infections reported overall. Non-VAD infection was the largest category, 4,501: 34.0% pneumonias, 30.6% non-VAD-related bloodstream infections (BSIs), 24.15% urinary tract infections (UTIs), and 10.2% gastrointestinal infections. VAD-specific infection was the second largest category, 1,756: 82.9% driveline, 12.8% pocket, and 4.3% pump/or cannula infections. VAD-related infection was the smallest category, 501: 47.5% BSIs, 47.5% mediastinitis, and 5.0% mediastinitis/pocket infections. All 3 categories were more frequently reported ≤ 3 months after implant.

CONCLUSIONS

Non-VAD infection, including pneumonia, BSI, UTI, and gastrointestinal infection, was the leading category of infection in MCS patients and the most frequently reported ≤ 3 months after implant. These results provide evidence to support resourcing and strengthening infection prevention strategy early after implantation in MCS.

Thrombocytopenia After Aortic Valve Replacement: Comparison Between Sutureless Perceval S Valve and Perimount Magna Ease Bioprosthesis

Introduction

The incidence of postoperative thrombocytopenia after aortic valve replacement (AVR) with the Perceval S Sutureless bioprosthesis remains unclear. The aim of this study was to report thrombocytopenia associated with the use of sutureless AVR.

Methods

The data was collected retrospectively for patients who had isolated AVR with sutureless Perceval S valve (Group A: 72 patients) and was compared with patients who underwent isolated sutured AVR with Perimount Magna Ease Bioprosthesis (Group B: 101 patients) in our institution between June 2014 and January 2017.

Results

Cardiopulmonary bypass and cross-clamp time were significantly shorter in group A. Maximum drop in platelet count was 58% mean (day 2.3) in group A versus 44% mean (day 1.7) in group B (P=0.0001). Absolute platelet count on postoperative day 1-6 in group A was significantly less than in group B (P≤0.05). Platelet count recovered to preoperative value in 44% patients in group B versus only in 26% patients in group A at discharge (P=0.018). Moderate thrombocytopenia occurs more often in group A (41% vs. 26%) (P=0.008) while severe thrombocytopenia (<50 x 10⁹) was observed in 6% in group A but never in group B. Platelets (P=0.007) and packed red blood cells (P=0.009) transfusion was significantly higher in the group A.

Conclusion

The implantation of sutureless Perceval aortic valves was associated with a significant drop in platelet count postoperatively with slow recovery and higher platelets and packed red blood cells transfusion requirements. A prospective randomised trial is needed to confirm our findings.

Aortic Valve Replacement with a Conventional Stented Bioprosthesis versus Sutureless Bioprosthesis: a Study of 763 Patients

OBJECTIVE

The aim of this retrospective study was to compare early postoperative outcomes after aortic valve replacement (AVR) with sutureless bioprostheses and conventional stented bioprostheses implanted through median sternotomy.

METHODS

From January 2011 to December 2016, 763 patients underwent aortic valve replacement with bioprostheses; of these, 139 received a Perceval S sutureless valve (Group A) and 624 received a Perimount Magna Ease valve (Group B). These groups were further divided into A1 (isolated Perceval AVR), A2 (Perceval AVR with coronary artery bypass grafting [CABG]), B1 (isolated conventional stented bioprosthesis), and B2 (conventional stented bioprosthesis + CABG).

RESULTS

Patients in Group A were older (mean 74 years vs. 71 years; P<0.0001), predominantly women (53% vs. 32%; P<0.0001), had a higher logistic EuroSCORE (3.26 vs. 2.43; P<0.001), more preoperative atrial fibrillation (20% vs. 13%; P=0.03), and had a lower reopening rate for bleeding (2.1% vs. 6.7%; P=0.04). Compared to Group B1, Group A1 had shorter cross-clamp (mean 40 min vs. 57 min; P≤0.0001) and bypass times (mean 63 min vs. mean 80 min; P=0.02), and they bled less postoperatively (mean 295 ml vs. mean 393 ml; P=0.002). The mean gradient across Perceval valve was 12.5 mmHg while its effective orifice area was 1.5 cm2.

CONCLUSION

In our retrospective study of 763 patients, sutureless valve group patients are older, mostly women, more symptomatic preoperatively, and have higher logistic EuroSCORE. They have shorter cross-clamp and bypass times, less postoperative bleeding, and reduced incidence of reopening. Further studies are needed to evaluate the clinical benefits in short, mid, and long-terms.

Donor and recipient risk factor analysis of inferior postheart transplantation outcome in the era of durable mechanical assist devices

The study objective is to quantify the impact of donor and recipient variables on heart transplant survival in recipients with a significant proportion of implanted continuous-flow left ventricular assist devices (LVADs). This is a prospective cohort study of International Society for Heart and Lung Transplantation (ISHLT) Registry that includes all primary heart-alone transplants in adult recipients (January 2005 and June 2013, N = 15 532, 27% LVADs). Donor and recipient characteristics were assessed for association with death or graft failure within 90 days and between 90 days and 5 years after transplantation. On Cox proportional hazard model donor cause of death other than head trauma (hazard ratio [HR] 1.985, P < 0.0001), recipient congenital (HR 2.7555, P < 0.0001) and ischemic (HR 1.165, P = 0.0383) vs dilated etiology and female donor heart transplanted into male recipient (HR 1.207, P = 0.0354) were predictors of death or graft failure within 90 days. Between 90 days and 5 years, donor cigarette use (HR 1.232, P = 0.0001), recipient cigarette use (HR 1.193, P = 0.0003), diabetes (HR 1.159, P = 0.0050), arterial hypertension (HR 1.129, P = 0.0115), and ischemic vs dilative cardiomyopathy had an increased probability of death or graft failure.

Patient survival and therapeutic outcome in the UK bridge to transplant left ventricular assist device population

Objective

To study the survival and patient outcome in a population of UK patients supported by an implantable left ventricular assist device (LVAD) as a bridge to heart transplantation.

Methods

Data on all adult patients (n=342) who received a HeartMate II or HVAD as a first long-term LVAD between January 2007 and 31 December 2013 were extracted from the UK Ventricular Assist Device (VAD) Database in November 2015. Outcomes analysed include survival on a LVAD, time to urgent listing, heart transplantation and complications including those needing a pump exchange.

Results

112 patients were supported with the Thoratec HeartMate II and 230 were supported with the HeartWare HVAD. Median duration of support was 534 days. During the study period, 81 patients required moving to the UK urgent waiting list for heart transplantation. Of the 342 patients, 85 (24.8%) received a heart transplant, this included 63 on the urgent list. Thirty-day survival was 88.9%, while overall patient survival at 3 years from LVAD implant was 49.6%. 156 patients (46%) died during LVAD support; the most common cause of death on a VAD was a cerebrovascular accident. There was no significant difference between the two devices used in any outcome.

Conclusions

In a population of patients with advanced heart failure, who have a very poor prognosis, support with an implantable LVAD allowed a quarter to receive a heart transplant in a 3-year period. Overall survival of the cohort was about 50%. With improvement in technology and in post-LVAD management, it is likely that outcomes will improve further.

Bloodstream infections in mechanical circulatory support device recipients in the International Society of Heart and Lung Transplantation Mechanically Assisted Circulation Support Registry: Epidemiology, risk factors, and mortality

BACKGROUND

We used multicenter international data from the International Society of Heart and Lung Transplantation Mechanically Assisted Circulation Support (IMACS) registry to determine bloodstream infection (BSI) event rate, independent risk factors, and association with mortality.

METHODS

Included were patients registered in IMACS from January 2013 through December 2015, assessed BSI event rate of mechanical circulatory support (MCS) and non-MCS-related BSIs, and conducted univariate and multivariate analyses between BSI with baseline characteristics and mortality.

RESULTS

We documented 1,606 BSIs in 1,231 of 10,171 MCS recipients (12%), with an event rate of 2.43 BSIs/100 patient-months within 3 months after implant (early onset) and 1.03 BSIs/100 patient-months after 3 months (late onset). Of these episodes, 1,378 (85.8%) were non- MCS-related BSI. Increasing body mass index and bilirubin were independent correlates of MCS-related BSI. Independent correlates of non-MCS-related BSI included older age, higher body mass index, previous cardiac surgery, baseline chronic renal disease and dialysis, pre-implant frailty, presence of biventricular assist device, total artificial heart or right ventricular assist device, and Interagency Registry for Mechanically Assisted Circulatory Support category 1. Survival after 3 months after implant of patients who developed early-onset BSI was 56.9% at 24 months vs 77.4% in patients without early-onset BSI (p < 0.001). Early-onset BSI was an independent correlate of mortality at 3 months after implantation (hazard ratio, 2.56; 95% confidence interval, 2.09-3.15; p < 0.001).

CONCLUSIONS

Early-onset BSI was associated with significantly increased 24-month mortality. More than 85% of these BSIs were not device related. There is an opportunity for infection prevention practices to decrease the BSI event rate, which may affect 24-month survival. These data can also serve as benchmarking for individual institutions.

Early Clinical Results of Perceval Sutureless Aortic Valve in 139 Patients: Freeman Experience

Objective

The aim of this retrospective study is to evaluate the safety and performance of the Perceval sutureless valve in patients undergoing aortic valve replacement. We report the 30-day clinical outcomes of 139 patients.

Methods

From January 2014 to December 2016, 139 patients underwent sutureless aortic valve replacement. Their operation notes, National Adult Cardiac Surgery Database and perioperative transoesophageal echocardiography findings were studied retrospectively.

Results

Ninety-two patients underwent isolated aortic valve replacement (group A) with Perceval valve and 47 patients had combined procedures of aortic valve replacement and coronary artery bypass grafting (group B). The patients received a size S (n=23), M (n=39), L (n=42) or XL (n=35) prosthesis. Perceval valve was successfully implanted in 135 (97.1%) patients. Mean cross-clamping time and bypass time were 40 and 63 minutes for isolated cases, while 68 and 107 minutes for combined cases. Three (2.1%) patients died within 30 days. Four patients suffered stroke and 5 patients went into acute renal failure. Median intensive care unit and hospital stay was 2 and 8.5, respectively. Four valves were explanted due to significant paravalvular leak after surgery. Five patients had permanent pacemaker as a result of complete heart block and mean postoperative drainage was 295 mL for isolated case and 457 mL for combined cases. The mean gradient across Perceval valve was 12.5 mmHg while its effective orifice area was 1.5 cm².

Conclusion

Early postoperative results showed that Perceval valve is safe. Further follow up is needed to evaluate the long-term outcome with this bioprosthesis.

Pre-transplant ventricular assist device explant

Explantation of a left ventricular assist device (LVAD) may be challenging even in the most experienced hands. We aim to describe the technique for explantation of an LVAD together with the heart as applicable to all contemporary implantable mechanical assist devices. In order to ensure safe explantation, particular care must be taken at three distinct stages: at the time of LVAD implantation, at pre-transplant assessment and at the time of heart transplantation. The preparation for a safe explantation at LVAD implantation includes positioning the driveline and the outflow graft away from the back of the sternum to ensure protection from injury during re-entry into the chest. At transplant assessment, essential investigations include computed tomography (CT) of the chest and ultrasound imaging of femoral vessels. At the time of heart transplantation, the site of peripheral access should be prepared and vessels exposed in case of a need for emergency bypass. We advise careful dissection starting from the lower aspect of the under surface of the sternum, moving as proximally as possible before attempting to use the oscillating saw. Much of the dissection of the heart is done off-pump. Cardiopulmonary bypass may be established either through peripheral vessels or the outflow graft in an emergency. Central direct cannulation is then established. After the heart and major vessels are isolated, explantation of the heart may begin either en-bloc or after splitting the ventricles in a sagittal plane. The basal regions of both ventricles and both atria are removed, leaving generous cuffs for anastomosis of the left atrium, pulmonary artery, aorta, inferior and superior vena cava (SVC). The apex of the heart is then removed with the device taking care not to injure the phrenic nerve.