Bridge to removal: a paradigm shift for left ventricular assist device therapy

Drug therapy and catheter ablation for management of arrhythmias in continuous flow left ventricular assist device's patients: a Clinical Consensus Statement of the European Heart Rhythm Association and the Heart Failure Association of the ESC

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure. Although these devices effectively improve survival, atrial and ventricular arrhythmias are common with a prevalence of 20-50% at one year after LVAD implantation. Arrhythmias predispose these patients to additional risk and are associated with considerable morbidity from recurrent implantable cardioverter-defibrillator shocks, progressive failure of the unsupported right ventricle, and herald an increased risk of mortality. Management of patients with arrhythmias and LVAD differs in many aspects from the general population heart failure patients. These include ruling out the reversible causes of arrhythmias that in LVAD patients may include mechanical irritation from the inflow cannula and suction events. For patients with symptomatic arrhythmias refractory to medical treatment, catheter ablation might be relevant. There are specific technical and procedural challenges perceived to be unique to LVAD-related ventricular tachycardia (VT) ablation such as vascular and LV access, signal filtering, catheter manoeuvrability within decompressed chambers, and electroanatomic mapping system interference. In some patients, the arrhythmogenic substrate might not be readily accessible by catheter ablation after LVAD implantation. In this regard, the peri-implantation period offers a unique opportunity to surgically address arrhythmogenic substrate and suppress future VT recurrences. This document aims to address specific aspects of the management of arrhythmias in LVAD patients focusing on anti-arrhythmic drug therapy and ablations.

Deactivation of LVAD support for myocardial recovery-surgical perspectives

Left ventricular assist devices (LVADs) are excellent therapies for advanced heart failure patients either bridged to transplant or for lifetime use. LVADs also allow for reverse remodeling of the failing heart that is often associated with functional improvement. Indeed, growing enthusiasm exists to better understand this population of patients, whereby the LVAD is used as an adjunct to mediate myocardial recovery. When patients achieve benchmarks suggesting that they no longer need LVAD support, questions related to the discontinuation of LVAD therapy become front and center. The purpose of this review is to provide a surgical perspective on the practical and technical issues surrounding LVAD deactivation.

Incidence, Outcomes, and Opportunity for Left Ventricular Assist Device Weaning for Myocardial Recovery

BACKGROUND

Myocardial recovery occurs in patients with advanced heart failure on left ventricular assist device (LVAD) support, but there is the premise that it is rare with uncertain results.

OBJECTIVES

The goal of this study was to investigate the incidence and consequence of LVAD explant after myocardial recovery.

METHODS

Using the United Network for Organ Sharing registry, LVAD implants in the United States between 2005 and 2020 were tracked until death, transplantation, or explant for myocardial recovery. The cohort undergoing explant was followed up for heart failure relapse (defined as relisting followed by delisting due to death, being too ill, or transplantation; or second durable LVAD implant).

RESULTS

Of 15,728 LVAD implants, 126 patients underwent explant for recovery, which only occurred in 55 (38%) of 145 implanting centers. The crude cumulative incidence was 0.7% at 2 years, whereas the incidence reached 4.7% among designated centers in the selected young nonischemic cohort. Of 126 explanted patients, 76 (60%) were subsequently delisted for sustained recovery. Heart failure relapsing had a relatively higher hazard in the early phase, with a 30-day incidence of 6% (7 of 126) but tapered following with the freedom rate of 72.5% at 4 years.

CONCLUSIONS

In the United States, LVAD explant for myocardial recovery was underutilized, leading to a very low incidence at the national level despite a realistic rate being achieved in designated centers for selected patients. With follow-up extending up to 4 years after explant, more than one-half were successfully removed and stayed off the waitlist, and approximately 70% were free from heart failure relapse events.

Perceptions of Bedside Nurses Caring for Patients with Left Ventricular Assist Devices (LVAD): A Qualitative Study

Introduction

Bedside nurses in the intensive care units are exposed to multiple challenges in their regular practice and recently have taken in ventricular assist device care in Lebanon since its introduction as a fairly new practice.

Objectives

To explore the experiences of nursing staff who work in Lebanese hospitals with Left Ventricular Assist Devices (LVAD).

Methods

This study employed a qualitative phenomenological research design, where semi-structured interviews were carried out among fifteen LVAD nurses in an acute care hospital.

Results

The qualitative data analysis produced six main themes. The first theme prevalent was "LVAD incompetence and shortage" and it reflected the deficit in properly structured training and the number of specialized LVAD nurses. The second theme that resulted from the analysis was titled, "Patient and family knowledge", which indicated the misconceptions that families and patients usually hold about LVAD which usually sugarcoats the situation. This was followed by "Burden of complications", "LVAD patient selection", "Perception of the LVAD team as invulnerable", and "High workload and patient frailty" which reflected the perspectives of LVAD nurses.

Conclusion

This study shows that the Lebanese LVAD nurses who participated in this study perceived inadequate competence, yet lacked proper training and induction. The nurses reported multiple challenges relating to care tasks, workload, and patient and family interactions which need to be addressed by coordinators.

Benchtop Models of Patient-Specific Intraventricular Flow During Heart Failure and LVAD Support

The characterization of intraventricular flow is critical to evaluate the efficiency of fluid transport and potential thromboembolic risk but challenging to measure directly in advanced heart failure (HF) patients with left ventricular assist device (LVAD) support. The study aims to validate an in-house mock loop (ML) by simulating specific conditions of HF patients with normal and prosthetic mitral valves (MV) and LVAD patients with small and dilated left ventricle volumes, then comparing the flow-related indices result of vortex parameters, residence time (RT), and shear-activation potential (SAP). Patient-specific inputs for the ML studies included heart rate, end-diastolic and end-systolic volumes, ejection fraction, aortic pressure, E/A ratio, and LVAD speed. The ML effectively replicated vortex development and circulation patterns, as well as RT, particularly for HF patient cases. The LVAD velocity fields reflected altered flow paths, in which all or most incoming blood formed a dominant stream directing flow straight from the mitral valve to the apex. RT estimation of patient and ML compared well for all conditions, but SAP was substantially higher in the LVAD cases of the ML. The benchtop system generated comparable and reproducible hemodynamics and fluid dynamics for patient-specific conditions, validating its reliability and clinical relevance. This study demonstrated that ML is a suitable platform to investigate the fluid dynamics of HF and LVAD patients and can be utilized to investigate heart-implant interactions.

LVAD therapy as a catalyst to heart failure remission and myocardial recovery

The management of chronic heart failure over the past decade has witnessed tremendous strides in medical optimization and device therapy including the use of left ventricular assist devices (LVAD). What we once thought of as irreversible damage to the myocardium is now demonstrating signs of reverse remodeling and recovery. Myocardial recovery on the structural, molecular, and hemodynamic level is necessary for sufficient recovery to withstand explant and achieve sustained recovery post-LVAD. Guideline-directed medical therapy and unloading have been shown to aid in recovery with the potential to successfully explant the LVAD. This review will summarize medical optimization, assessment for recovery, explant methodologies and outcomes post-recovery with explant of durable LVAD.

Myocardial recovery in children supported with a durable ventricular assist device-a systematic review

OBJECTIVES

A small percentage of paediatric patients supported with a ventricular assist device (VAD) can have their device explanted following myocardial recovery. The goal of this systematic review is to summarize the current literature on the clinical course in these children after weaning.

METHODS

A systematic literature search was performed on 27 May 2022 using Embase, Medline ALL, Web of Science Core Collection, Cochrane Central Register of Controlled Trials and Google Scholar to include all literature on paediatric patients supported by a durable VAD during the last decade. Overlapping study cohorts and registry-based studies were filtered out.

RESULTS

Thirty-seven articles were included. Eighteen of them reported on the incidence of recovery in cohort studies, with an overall incidence rate of 8.7% (81/928). Twenty-two of the included articles reported on clinical outcomes after VAD explantation (83 patients). The aetiologies varied widely and were not limited to diseases with a natural transient course like myocarditis. Most of the patients in the included studies (70; 84.3%) were supported by a Berlin Heart EXCOR, and in 66.3% (55/83), only the left ventricle had to be supported. The longest follow-up period was 19.1 years, and multiple studies reported on long-term myocardial recovery. Fewer than half of the reported deaths had a cardiac cause.

CONCLUSIONS

Myocardial recovery during VAD support is dependent on various contributing components. The interactions among patient-, device-, time- and hospital-related factors are complex and not yet fully understood. Long-term recovery after VAD support is achievable, even after a long duration of VAD support, and even in patients with aetiologies different from myocarditis or post-cardiotomy heart failure. More research is needed on this favourable outcome after VAD support.

Myocardial recovery following left ventricular assist device implantation

Durable left ventricular assist devices (LVADs) have consistently shown improved mortality and morbidity in patients with end-stage heart failure. Select patients with LVADs may experience significant enough myocardial recovery after device implantation to allow for explantation or decommissioning. While earlier trials suggested a high incidence of recovery, real-world clinical data have demonstrated this to be a much rarer phenomenon. Whether or not patients experience recovery, practices such as speed optimization and usage of guideline-directed medical therapy can improve patient outcomes.

Defining cardiac functional recovery in end-stage heart failure at single-cell resolution

Recovery of cardiac function is the holy grail of heart failure therapy yet is infrequently observed and remains poorly understood. In this study, we performed single-nucleus RNA sequencing from patients with heart failure who recovered left ventricular systolic function after left ventricular assist device implantation, patients who did not recover and non-diseased donors. We identified cell-specific transcriptional signatures of recovery, most prominently in macrophages and fibroblasts. Within these cell types, inflammatory signatures were negative predictors of recovery, and downregulation of RUNX1 was associated with recovery. In silico perturbation of RUNX1 in macrophages and fibroblasts recapitulated the transcriptional state of recovery. Cardiac recovery mediated by BET inhibition in mice led to decreased macrophage and fibroblast Runx1 expression and diminished chromatin accessibility within a Runx1 intronic peak and acquisition of human recovery signatures. These findings suggest that cardiac recovery is a unique biological state and identify RUNX1 as a possible therapeutic target to facilitate cardiac recovery.

HeartMate 3 Explantation Using Felt Plug for Ventriculotomy Occlusion

Left ventricular assist devices (LVAD) can be utilized for heart failure patients as a bridge to transplant, bridge to destination, or bridge to recovery. Given the lack of a universally accepted consensus for assessing myocardial recovery, techniques and strategies in LVAD explantation also vary. In addition, the incidence of LVAD explantation remains relatively low, and surgical techniques of explantation continue to be areas of interest. Our approach using a felt-plug Dacron technique is an effective way to preserve left ventricular geometry and cardiac function.

Clinical myocardial recovery in advanced heart failure with long term left ventricular assist device support

Left ventricular assist-device (LVAD) implantation is a life-saving therapy for patients with advanced heart failure (HF). With chronic unloading and circulatory support, LVAD-supported hearts often show significant reverse remodeling at the structural, cellular and molecular level. However, translation of these changes into meaningful cardiac recovery allowing LVAD explant is lagging. Part of the reason for this discrepancy is lack of anticipation and hence promotion and evaluation for recovery post LVAD implant. There is additional uncertainty about the long-term course of HF following LVAD explant. In selected patients, however, guided by the etiology of HF, duration of disease and other clinical factors, significant functional improvement and LVAD explantation with long-term freedom from recurrent HF events has been demonstrated to be feasible in a reproducible manner. The identified predictors of myocardial recovery suggest that the elective therapeutic use of potentially less invasive VADs for reversal of HF earlier in the disease process is a future goal that warrants further investigation. Hence, it is prudent to develop and implement tools to predict HF reversibility prior to LVAD implant, optimize unloading-promoted recovery with guideline directed medical therapy and monitor for myocardial improvement. This review article summarizes the clinical aspects of myocardial recovery and together with its companion review article focused on the biological aspects of recovery, they aim to provide a useful framework for clinicians and investigators.

The CorInnova Implantable Cardiac Assist System for Direct Cardiac Compression

The CorInnova cardiac compression device (CorInnova, Inc., Houston, TX, USA) is designed to provide direct biventricular support, increase cardiac output, and improve ventricular unloading in patients with heart failure. Placed within the pericardium and surrounding both ventricles, the device has two concentric sets of thin-film polyurethane chambers: (1) inner (epicardial) saline-filled chambers that conform intimately to the epicardial surface, eradicating any gaps in the interface between the device and the heart; and (2) outer air-filled chambers cycled to provide epicardial compression during systole and negative epicardial pressure during diastole, consistent with physiological cardiac contraction and relaxation. A superelastic, collapsible Nitinol frame gives the device structure, enables minimally invasive self-deployment, and enhances diastolic filling. Preclinical testing has been extremely promising, with improvements in cardiac output and other cardiac parameters in animal heart failure models. This potentially transformative technology is moving rapidly toward first-in-human use. The CorInnova device may provide an effective device-based solution for patients with heart failure who currently have few or limited mechanical cardiac support options, including patients with biventricular cardiac failure, those with right heart failure, those who are older, and those who are of smaller size. It can be removed easily and requires minimal maintenance. An important, unique feature of this technology is that it provides mechanical cardiac assistance without blood contact or need for anticoagulation. The CorInnova device may be particularly important for those patients who have contraindications to anticoagulation due to allergy, neurological bleeds, or preexisting hemorrhage. No other mechanical circulatory support device addresses these underserved heart-failure populations.

Myocardial recovery evaluation from ventricular assist device in patients with dilated cardiomyopathy

AIMS

The removal of left ventricular assist device (LVAD) after myocardial recovery can provide survival benefits with freedom from LVAD-associated complications. However, in the absence of standardization, the weaning evaluation and surgical strategy differ widely among centres. Therefore, we analysed the experiences of LVAD explantation with our protocol in dilated cardiomyopathy (DCM) patients and investigated the validity of our weaning evaluation and surgical strategy from the perspective of optimal long-term survival.

METHODS AND RESULTS

All LVAD explantation patients in our institution between May 2012 and May 2020 were enrolled. All patients were evaluated by our three-phase weaning assessment: (i) clinical stability with improved cardiac function under LVAD support; (ii) haemodynamic stability shown by ramp-loading and saline-loading test; (iii) intraoperative pump-off test. Explant surgery involved removal of the whole system including driveline, pump, sewing ring and outflow-graft, and closure of an apical hole. Intra-operative, peri-operative, and post-operative outcomes, including all-cause mortality and LVAD associated major complications, were retrospectively analysed. A total of 12 DCM patients (DuraHeart, n = 2; EVAHEART, n = 2; HeartMate II, n = 6; HeartMate 3, n = 2) had myocardial recovery after a median 10 months [interquartile range (IQR); 6.3-15 months] support and qualified for our LVAD explantation study protocol [median age: 37 y, IQR; 34-41 years; 83% men]. The median left ventricular ejection fraction was 20% (IQR; 12-23%) at LVAD-implantation and 54% (IQR: 45-55%) before LVAD explantation (P < 0.001). There were no perioperative complications and median ICU stay was 4 days (IQR; 2-4 days). All patients were discharged after a median of 24 days (IQR: 17-28 days) postoperatively. No patient suffered from any cardiac event (heart failure hospitalization, re-implantation of LVAD, or heart transplantation) at a median of 40 months (IQR: 17-58 months) follow up. All patients are alive with NYHA functional class 1 with preserved left ventricular function.

CONCLUSIONS

The evaluation of LVAD explant candidates by our weaning protocol was safe and effective. In the patients completing our protocol successfully, LVAD explantation is feasible and an excellent long-term cardiac event free-survival seems to be achieved.

Successful pregnancy with left ventricular assist device failure in the setting of peripartum cardiomyopathy

Pregnancy is contraindicated for women with left ventricular dysfunction due to high maternal and fetal mortality. We present a case of a pregnant 31-year-old woman with a history of heart failure due to peripartum cardiomyopathy from a previous pregnancy. She had a left ventricular assist device (LVAD) and was on warfarin due to recurrent thrombosis of her device. During her course, she had multiple cardiac complications, including thrombosis of the LVAD, which required deactivation. At 32 weeks, a cesarean section was performed due to acute decompensation, and a transthoracic echocardiogram revealed a left ventricular ejection fraction of 30% to 34%, a dilated left ventricle, and moderate global hypokinesis. This case highlights the need for coordinated care from cardiologists and maternal-fetal medicine specialists to minimize symptoms to obtain ideal outcomes for mother and infant despite LVAD deactivation.

Society for Cardiovascular Magnetic Resonance 2020 Case of the Week series

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). Case of the week is a case series hosted on the SCMR website ( https://www.scmr.org ) that demonstrates the utility and importance of CMR in the clinical diagnosis and management of cardiovascular disease. Each case consists of the clinical presentation and a discussion of the condition and the role of CMR in diagnosis and guiding clinical management. The cases are all instructive and helpful in the approach to patient management. We present a digital archive of the 2020 Case of the Week series of 11 cases as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

Impact of symptom-guided, progressive cardiac rehabilitation after left ventricular assist device implantation

A 29-year-old woman with a left ventricular assist device (LVAD) completed a progressive, symptom-limited cardiac rehabilitation program consisting of boxing, weight-lifting, and aerobic exercise, where she improved her exercise capacity by 2.7 metabolic equivalents (P < 0.001) and demonstrated significant myocardial recovery, allowing for successful LVAD explant 9 months after implantation.

Weaning from ventricular assist device support after recovery from left ventricular failure with or without secondary right ventricular failure

Although complete myocardial recovery after ventricular assist device (VAD) implantation is rather seldom, systematic search for recovery is worthwhile because for recovered patients weaning from VADs is feasible and can provide survival benefits with long-term freedom from heart failure (HF) recurrence, even if a chronic cardiomyopathy was the primary cause for the drug-refractory HF necessitating left ventricular (LVAD) or biventricular support (as bridge-to-transplantation or definitive therapy) and even if recovery remains incomplete. LVAD patients explanted for myoacardial recovery compared to those transplanted from LVAD support showed similar survival rates and a significant proportion of explanted patients can achieve cardiac and physical functional capacities that are within the normal range of healthy controls. In apparently sufficiently recovered patients, a major challenge remains still the pre-explant prediction of the weaning success which is meanwhile reliably possible for experienced clinicians. In weaning candidates, the combined use of certain echocardiography and right heart catheterization parameters recorded before VAD explantation can predict post-weaning cardiac stability with good accuracy. However, in the absence of standardization or binding recommendations, the protocols for assessment of native cardiac improvement and also the weaning criteria differ widely among centers. Currently there are still only few larger studies on myocardial recovery assessment after VAD implantation. Therefore, the weaning practice relies mostly on small case series, local practice patterns, and case reports, and the existing knowledge, as well as the partially differing recommendations which are based mainly on expert opinions, need to be periodically systematised. Addressing these shortcomings, our review aims to summarize the evidence and expert opinion on the evaluation of cardiac recovery during mechanical ventricular support by paying special attention to the reliability of the methods and parameters used for assessment of myocardial recovery and the challenges met in both evaluation of recovery and weaning decision making.

A detailed explantation assessment protocol for patients with left ventricular assist devices with myocardial recovery

OBJECTIVES

Left ventricular assist device (LVAD) implantation for end-stage heart failure patients has been on the rise, providing a reliable long-term option. For some LVAD patients, longer term LV unloading leads to recovery; hence, the need for evaluating potential myocardial recovery and weaning eligibility has emerged.

METHODS

All patients who underwent contemporary LVAD explantation at our institution between 2009 and 2020 were included in the study. Patients in New York Heart Association I, left ventricular ejection fraction >40%, a cardiac index >2.4 l/min and a peak oxygen intake >50% predicted underwent a 4-phase weaning assessment. A minimally invasive approach using a titanium plug was the surgery of choice in the most recent explants. Kaplan-Meier curves were used to estimate the survival at 1 and 5 years.

RESULTS

Twenty-six patients (17 HeartMate II, 9 HeartWare) underwent LVAD explantation after a median 317 days of support [IQ (212-518)], range 131-1437. Mean age at explant was 35.8 ± 12.7 years and 85% were males. Idiopathic dilated cardiomyopathy was the underlying diagnosis in 70% of cases. Thirteen (48%) patients were on short-term mechanical circulatory support and 60% required intensive care unit admission prior to the LVAD implantation. At 1 year, Kaplan-Meier estimated survival was 88%, whereas at 6 years, it was 77%. The average left ventricular ejection fraction at 1 year post-explant was 44.25% ± 8.44.

CONCLUSIONS

The use of a standardized weaning protocol (echocardiographic and invasive) and a minimally invasive LVAD explant technique minimizes periprocedural complications and leads to good long-term device-free survival rates.

Interleukin-1 Receptor Antagonism as Adjunct Therapy for Heart Failure Patients with Left Ventricular Assist Devices

While left ventricular assist devices (LVAD) successfully unload the failing ventricle, most hearts do not regain sufficient function to allow for device explantation. Herein, we report a pilot series of LVAD patients treated with interleukin-1 receptor antagonism as a biologic adjuvant that safely and effectively treated inflammation so as to create a milieu whereby the heart could functionally improve. This pilot study sets the stage for a more rigorous, controlled trial of interleukin-1 receptor antagonism in treating heart failure and promoting myocardial recovery in patients supported by LVADs.

Echocardiographic Assessment of Left Ventricular Assist Device Outflow Velocity During Percutaneous Decommissioning

Left ventricular assist devices (LVADs) have been used as an effective therapeutic option in patients with advanced heart failure, either as a bridge to transplantation or, in some patients, as a bridge to recovery. LVAD withdrawal with ventricular recovery represents the optimal outcome for patients previously implanted with an LVAD. In this E-Challenge, the authors present a case of percutaneous decommissioning of an LVAD, in which TEE provided critical, real-time perioperative evaluation. The authors also review the current perspectives on LVAD decommissioning in terms of patient selection and surgical techniques.

The Partial Support of the Left Ventricular Assist Device Shifts the Systemic Cardiac Output Curve Upward in Proportion to the Effective Left Ventricular Ejection Fraction in Pressure-Volume Loop

Left ventricular assist device (LVAD) has been saving many lives in patients with severe left ventricular (LV) failure. Recently, a minimally invasive transvascular LVAD such as Impella enables us to support unstable hemodynamics in severely ill patients. Although LVAD support increases total LV cardiac output (CO_TLV) at the expense of decreases in the native LV cardiac output (CO_NLV), the underlying mechanism determining CO_TLV remains unestablished. This study aims to clarify the mechanism and develop a framework to predict CO_TLV under known LVAD flow (CO_LVAD). We previously developed a generalized framework of circulatory equilibrium that consists of the integrated CO curve and the VR surface as common functions of right atrial pressure (P_RA) and left atrial pressure (P_LA). The intersection between the integrated CO curve and the VR surface defines circulatory equilibrium. Incorporating LVAD into this framework indicated that LVAD increases afterload, which in turn decreases CO_NLV. The total LV cardiac output (CO_TLV) under LVAD support becomes CO_TLV = CO_NLV+EF_e · CO_LVAD, where EF_e is effective ejection fraction, i.e., E_es/(E_es+E_a). E_es and E_a represent LV end-systolic elastance (E_es) and effective arterial elastance (E_a), respectively. In other words, LVAD shifts the total LV cardiac output curve upward by EF_e · CO_LVAD. In contrast, LVAD does not change the VR surface or the right ventricular CO curve. In six anesthetized dogs, we created LV failure by the coronary ligation of the left anterior descending artery and inserted LVAD by withdrawing blood from LV and pumping out to the femoral artery. We determined the parameters of the CO curve with a volume-change technique. We then changed the CO_LVAD stepwise from 0 to 70–100 ml/kg/min and predicted hemodynamics by using the proposed circulatory equilibrium. Predicted CO_TLV, P_RA, and P_LA for each step correlated well with those measured (SEE; 2.8 ml/kg/min 0.17 mmHg, and 0.65 mmHg, respectively, r²; 0.993, 0.993, and 0.965, respectively). The proposed framework quantitatively predicted the upward-shift of the total CO curve resulting from the synergistic effect of LV systolic function and LVAD support. The proposed framework can contribute to the safe management of patients with LVAD.

A Scalable Approach to Determine Intracardiac Pressure From Mechanical Circulatory Support Device Signals

OBJECTIVE

Effective mechanical circulatory support (MCS) relies on cardiac function measures to guide titration. Left ventricular end diastolic pressure (LVEDP) is a useful measure that is indirectly estimated using pulmonary artery catheters (PACs). PACs require additional intervention and provide intermittent and unreliable estimations. MCS device signals can estimate LVEDP but are prone to inter-device variability and require rigorous specialized characterization. We present a scalable and implementable approach to calculate LVEDP continuously using device signals.

METHODS

LVEDP was calculated from MCS device measured aortic pressure and motor current, which approximates the pressure head between the aorta and left ventricle. This motor current-pressure head relationship is device-specific but approximated using existing flow calibration and assumed physiologic relationships. Performance was evaluated with comparison from direct measurement of LVEDP in a series of acute animal models.

RESULTS

LVEDP measures (n = 178,279) from 18 animals had good correlation (r = 0.84) and calibration (Bland-Altman limits of agreement -7.77 to 7.63 mmHg; mean bias -0.07 ± 0.02 mmHg). The total mean error prediction interval was -3.42 to 3.32 mmHg and RMS error was 3.85 mmHg.

CONCLUSION

LVEDP can be continuously calculated using device signals without specialized characterization. Calculated LVEDP values improved upon PAC estimations and were found using a scalable and manufacturer-accessible method.

SIGNIFICANCE

This method improves upon existing LVEDP measures without the need for rigorous characterization, external calibration, or additional intervention; this allows widescale deployment of continuous LVEDP measurement for patients on MCS and demonstrates key considerations necessary to translate research-grade technologies.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

To explore the prevalence and outcomes of advance care planning for patients with left ventricular assist devices: A review

AIMS AND OBJECTIVES

To explore the prevalence and outcomes of advance care planning for patients with left ventricular assist devices: a review.

BACKGROUND

End-stage heart failure is associated with significant symptom burden at rest. Left ventricular assist devices are not curative; nevertheless, they alleviate symptoms and prolong survival. Evidence suggests that most patients with left ventricular assist devices and their families do not have open discussions regarding end-of-life wishes until catastrophic complications arise. Therefore, it is important to understand reasons for this, so healthcare professionals such as nurses can facilitate the process.

DESIGN

A mixed-studies integrative review with a narrative synthesis of the evidence. PRISMA guidelines were followed for reporting systematic qualitative reviews.

METHOD

A search of four electronic data in January 2018 and a hand search yielded 139 citations; seven studies met the review eligibility criteria. Methodological quality of the selected studies was evaluated, and data were extracted and compiled.

RESULTS

Three themes were identified: prevalence and feasibility of advanced care planning, advance care planning developed for patients with device support, patients' and caregivers' perceptions of advanced care planning discussions. Advanced care planning is underused routinely implemented in left ventricular device centres. Pre-implantation advanced care planning is feasible and results in the highest rate of documented advance decisions which are useful for both patients and their loved ones in cases of complications.

CONCLUSION

Strong evidence that left ventricular assist-specific advanced care planning is recommended for all left ventricular assist device patients to enable their treatment preferences in case of incurable complications. Palliative care services should collaborate with nurses in designing and facilitating advanced care planning for delisted transplant patients. Patients with left ventricular devices awaiting heart transplant and those waiting for myocardium healing are underrepresented in the current studies. Research on the optimal timing of advanced care planning in these groups of patients is indicated.

RELEVANCE FOR CLINICAL PRACTICE

There is a need for improved approaches to advanced care planning for and with people with left ventricular devices.

Evaluation of the CorInnova Heart Assist Device in an Acute Heart Failure Model

While the number of patients supported with temporary cardiac assist is growing, the existing devices are limited by a multitude of complications, mostly related to contact with the blood. The CorInnova epicardial compressive heart assist device was tested in six sheep using an acute heart failure model. High esmolol dose, targeting a 50% reduction in CO from healthy baseline, resulted in a failure state with mean CO 1.9 L/min. Heart assist with the device during failure state resulted in an average absolute increase in CO of 1.0 L/min, along with a decline in ventricular work to 67.5% of the total LV SW. Combined with repeated success of minimally invasive device implant, the resulting increases in cardiac hemodynamics achieved while still unloading the heart demonstrate the potential of the CorInnova device for temporary heart assist.

Partial Mechanical Unloading of the Heart Disrupts L-Type Calcium Channel and Beta-Adrenoceptor Signaling Microdomains

Introduction: We investigated the effect of partial mechanical unloading (PMU) of the heart on the physiology of calcium and beta-adrenoceptor-cAMP (βAR-cAMP) microdomains. Previous studies have investigated PMU using a model of heterotopic-heart and lung transplantation (HTHAL). These studies have demonstrated that PMU disrupts the structure of cardiomyocytes and calcium handling. We sought to understand these processes by studying L-Type Calcium Channel (LTCC) activity and sub-type-specific βAR-cAMP signaling within cardiomyocyte membrane microdomains.

Method: We utilized an 8-week model of HTHAL, whereby the hearts of syngeneic Lewis rats were transplanted into the abdomens of randomly assigned cage mates. A pronounced atrophy was observed in hearts after HTHAL. Cardiomyocytes were isolated via enzymatic perfusion. We utilized Förster Resonance Energy Transfer (FRET) based cAMP-biosensors and scanning ion conductance microscopy (SICM) based methodologies to study localization of LTCC and βAR-cAMP signaling.

Results: β₂AR-cAMP responses measured by FRET in the cardiomyocyte cytosol were reduced by PMU (loaded 28.51 ± 7.18% vs. unloaded 10.84 ± 3.27% N,n 4/10-13 mean ± SEM ^∗p < 0.05). There was no effect of PMU on β₂AR-cAMP signaling in RII_Protein Kinase A domains. β₁AR-cAMP was unaffected by PMU in either microdomain. Consistent with this SICM/FRET analysis demonstrated that β₂AR-cAMP was specifically reduced in t-tubules (TTs) after PMU (loaded TT 0.721 ± 0.106% vs. loaded crest 0.104 ± 0.062%, unloaded TT 0.112 ± 0.072% vs. unloaded crest 0.219 ± 0.084% N,n 5/6-9 mean ± SEM ^∗∗p < 0.01, ^∗∗∗p < 0.001 vs. loaded TT). By comparison β₁AR-cAMP responses in either TT or sarcolemmal crests were unaffected by the PMU. LTCC occurrence and open probability (P_o) were reduced by PMU (loaded TT P_o 0.073 ± 0.011% vs. loaded crest P_o 0.027 ± 0.006% N,n 5/18-26 mean ± SEM ^∗p < 0.05) (unloaded TT 0.0350 ± 0.003% vs. unloaded crest P_o 0.025 N,n 5/20-30 mean ± SEM NS ^#p < 0.05 unloaded vs. loaded TT). We discovered that PMU had reduced the association between Caveolin-3, Junctophilin-2, and Cav1.2.

Discussion: PMU suppresses’ β₂AR-cAMP and LTCC activity. When activated, the signaling of β₂AR-cAMP and LTCC become more far-reaching after PMU. We suggest that a situation of ‘suppression/decompartmentation’ is elicited by the loss of refined cardiomyocyte structure following PMU. As PMU is a component of modern device therapy for heart failure this study has clinical ramifications and raises important questions for regenerative medicine.

Cardiac Rotational Mechanics As a Predictor of Myocardial Recovery in Heart Failure Patients Undergoing Chronic Mechanical Circulatory Support: A Pilot Study

BACKGROUND

Impaired qualitative and quantitative left ventricular (LV) rotational mechanics predict cardiac remodeling progression and prognosis after myocardial infarction. We investigated whether cardiac rotational mechanics can predict cardiac recovery in chronic advanced cardiomyopathy patients.

METHODS AND RESULTS

Sixty-three patients with advanced and chronic dilated cardiomyopathy undergoing implantation of LV assist device (LVAD) were prospectively investigated using speckle tracking echocardiography. Acute heart failure patients were prospectively excluded. We evaluated LV rotational mechanics (apical and basal LV twist, LV torsion) and deformational mechanics (circumferential and longitudinal strain) before LVAD implantation. Cardiac recovery post-LVAD implantation was defined as (1) final resulting LV ejection fraction ≥40%, (2) relative LV ejection fraction increase ≥50%, (iii) relative LV end-systolic volume decrease ≥50% (all 3 required). Twelve patients fulfilled the criteria for cardiac recovery (Rec Group). The Rec Group had significantly less impaired pre-LVAD peak LV torsion compared with the Non-Rec Group. Notably, both groups had similarly reduced pre-LVAD LV ejection fraction. By receiver operating characteristic curve analysis, pre-LVAD peak LV torsion of 0.35 degrees/cm had a 92% sensitivity and a 73% specificity in predicting cardiac recovery. Peak LV torsion before LVAD implantation was found to be an independent predictor of cardiac recovery after LVAD implantation (odds ratio, 0.65 per 0.1 degrees/cm [0.49-0.87]; P=0.014).

CONCLUSIONS

LV rotational mechanics seem to be useful in selecting patients prone to cardiac recovery after mechanical unloading induced by LVADs. Future studies should investigate the utility of these markers in predicting durable cardiac recovery after the explantation of the cardiac assist device.

Clinical and histopathological effects of heart failure drug therapy in advanced heart failure patients on chronic mechanical circulatory support

AIMS

Adjuvant heart failure (HF) drug therapy in patients undergoing chronic mechanical circulatory support (MCS) is often used in conjunction with a continuous-flow left ventricular assist device (LVAD), but its potential impact is not well defined. The objective of the present study was to examine the effects of conventional HF drug therapy on myocardial structure and function, peripheral organ function and the incidence of adverse events in the setting of MCS.

METHODS AND RESULTS

Patients with chronic HF requiring LVAD support were prospectively enrolled. Paired myocardial tissue samples were obtained prior to LVAD implantation and at transplantation for histopathology. The Meds group comprised patients treated with neurohormonal blocking therapy (concurrent beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and aldosterone antagonist), and the No Meds group comprised patients on none of these. Both the Meds (n = 37) and No Meds (n = 44) groups experienced significant improvements in cardiac structure and function over the 6 months following LVAD implantation. The degree of improvement was greater in the Meds group, including after adjustment for baseline differences. There were no differences between the two groups in arrhythmias, end-organ injury, or neurological events. In patients with high baseline pre-LVAD myocardial fibrosis, treatment with HF drug therapy was associated with a reduction in fibrosis.

CONCLUSIONS

Clinical and histopathological evidence showed that adjuvant HF drug therapy was associated with additional favourable effects on the structure and function of the unloaded myocardium that extended beyond the beneficial effects attributed to LVAD-induced unloading alone. Adjuvant HF drug therapy did not influence the incidence of major post-LVAD adverse events during the follow-up period.

Single lung retrieval from a donor supported by a left ventricular assist device

The number of patients who need cardiac support with a left ventricular assist device (LVAD) has increased over the last decade. However, the number of reports of organ retrieval from donors with an LVAD is still small. Successful lung retrieval for single lung transplantation was performed from a donor on LVAD support. This required special care not to injure the heart, great vessels, and the device, particularly the outflow conduit, because of significant conglutination around the device. A right single lung transplantation was performed successfully, with no postoperative complications. This means that patients on an LVAD could be potential donors for lung transplantation.

Advancing the Science of Myocardial Recovery With Mechanical Circulatory Support: A Working Group of the National, Heart, Lung, and Blood Institute

The medical burden of heart failure (HF) has spurred interest in clinicians and scientists to develop therapies to restore the function of a failing heart. To advance this agenda, the National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group of experts from June 2 to 3, 2016, in Bethesda, Maryland, to develop NHLBI recommendations aimed at advancing the science of cardiac recovery in the setting of mechanical circulatory support (MCS). MCS devices effectively reduce volume and pressure overload that drives the cycle of progressive myocardial dysfunction, thereby triggering structural and functional reverse remodeling. Research in this field could be innovative in many ways, and the Working Group specifically discussed opportunities associated with genome-phenome systems biology approaches; genetic epidemiology; bioinformatics and precision medicine at the population level; advanced imaging modalities, including molecular and metabolic imaging; and the development of minimally invasive surgical and percutaneous bioengineering approaches. These new avenues of investigations could lead to new treatments that target phylogenetically conserved pathways involved in cardiac reparative mechanisms. A central point that emerged from the NHLBI Working Group meeting was that the lessons learned from the MCS investigational setting can be extrapolated to the broader HF population. With the precedents set by the significant effect of studies of other well-controlled and tractable subsets on larger populations, such as the genetic work in both cancer and cardiovascular disease, the work to improve our understanding of cardiac recovery and resilience in MCS patients could be transformational for the greater HF population.

Advancing the Science of Myocardial Recovery with Mechanical Circulatory Support: A Working Group of the National, Heart, Lung, and Blood Institute

The medical burden of heart failure (HF) has spurred interest in clinicians and scientists to develop therapies to restore the function of a failing heart. To advance this agenda, the National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group of experts from June 2-3, 2016, in Bethesda, MD, to develop NHLBI recommendations aimed at advancing the science of cardiac recovery in the setting of mechanical circulatory support (MCS). Mechanical circulatory support devices effectively reduce volume and pressure overload that drives the cycle of progressive myocardial dysfunction, thereby triggering structural and functional reverse remodeling. Research in this field could be innovative in many ways, and the Working Group specifically discussed opportunities associated with genome-phenome systems biology approaches; genetic epidemiology; bioinformatics and precision medicine at the population level; advanced imaging modalities, including molecular and metabolic imaging; and the development of minimally invasive surgical and percutaneous bioengineering approaches. These new avenues of investigations could lead to new treatments that target phylogenetically conserved pathways involved in cardiac reparative mechanisms. A central point that emerged from the NHLBI Working Group meeting was that the lessons learned from the MCS investigational setting can be extrapolated to the broader HF population. With the precedents set by the significant effect of studies of other well-controlled and tractable subsets on larger populations, such as the genetic work in both cancer and cardiovascular disease, the work to improve our understanding of cardiac recovery and resilience in MCS patients could be transformational for the greater HF population.

Advancing the Science of Myocardial Recovery With Mechanical Circulatory Support: A Working Group of the National, Heart, Lung and Blood Institute

The medical burden of heart failure (HF) has spurred interest in clinicians and scientists to develop therapies to restore the function of a failing heart. To advance this agenda, the National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group of experts on June 2-3, 2016, in Bethesda, Maryland, to develop recommendations for the NHLBI aimed at advancing the science of cardiac recovery in the setting of mechanical circulatory support (MCS). MSC devices effectively reduce volume and pressure overload that drives the cycle of progressive myocardial dysfunction, thereby triggering structural and functional reverse remodeling. Research in this field could be innovative in many ways, and the Working Group specifically discussed opportunities associated with genome-phenome systems biology approaches, genetic epidemiology, bioinformatics and precision medicine at the population level, advanced imaging modalities including molecular and metabolic imaging, and developing minimally invasive surgical and percutaneous bioengineering approaches. These new avenues of investigations could lead to new treatments that target phylogenetically conserved pathways involved in cardiac reparative mechanisms. A central point that emerged from the NHLBI Working Group meeting was that the lessons learned from the MCS investigational setting can be extrapolated to the broader HF population. With the precedents set by the significant impact of studies of other well controlled and tractable subsets on larger populations, such as the genetic work in both cancer and cardiovascular disease, the work to improve our understanding of cardiac recovery and resilience in MCS patients could be transformational for the greater HF population.

Hybrid Exclusion of HeartMate ІІ Left Ventricular Assist Device After Bridge to Recovery

We present a hybrid technique of left ventricular assist device exclusion after bridge to recovery in a pediatric patient, using percutaneous occlusion of the outflow graft and surgical excision of driveline. This technique has the advantage of avoiding chest reentry and cardiopulmonary bypass.

Current Status of Pediatric Ventricular Assist Device Support

The last decade has witnessed significant advancement in the field of ventricular assist device (VAD) support. Although device options for pediatric patients were previously severely limited because of body size constraints, this frustrating situation has gradually been changing, owing to ongoing device miniaturization. Recognition of the superiority of VAD support compared with conventional extracorporeal membrane oxygenation support has spurred enthusiasm for VAD support in children. In this article, we discuss the current status of pediatric VAD support; where do we stand now and where will we be heading? Because this field is rapidly changing, it is anticipated that this article will provide a general overview of what is currently occurring in the field of pediatric VAD support.

New Management Strategies in Heart Failure

Despite >100 clinical trials, only 2 new drugs had been approved by the US Food and Drug Administration for the treatment of chronic heart failure in more than a decade: the aldosterone antagonist eplerenone in 2003 and a fixed dose combination of hydralazine-isosorbide dinitrate in 2005. In contrast, 2015 has witnessed the Food and Drug Administration approval of 2 new drugs, both for the treatment of chronic heart failure with reduced ejection fraction: ivabradine and another combination drug, sacubitril/valsartan or LCZ696. Seemingly overnight, a range of therapeutic possibilities, evoking new physiological mechanisms, promise great hope for a disease that often carries a prognosis worse than many forms of cancer. Importantly, the newly available therapies represent a culmination of basic and translational research that actually spans many decades. This review will summarize newer drugs currently being used in the treatment of heart failure, as well as newer strategies increasingly explored for their utility during the stages of the heart failure syndrome.