Left Ventricular Assist Device Support and Myocardial Recovery in Recent Onset Cardiomyopathy

Advanced Heart Failure: Therapeutic Options and Challenges in the Evolving Field of Left Ventricular Assist Devices

Heart Failure is a chronic and progressively deteriorating syndrome that has reached epidemic proportions worldwide. Improved outcomes have been achieved with novel drugs and devices. However, the number of patients refractory to conventional medical therapy is growing. These advanced heart failure patients suffer from severe symptoms and frequent hospitalizations and have a dismal prognosis, with a significant socioeconomic burden in health care systems. Patients in this group may be eligible for advanced heart failure therapies, including heart transplantation and chronic mechanical circulatory support with left ventricular assist devices (LVADs). Heart transplantation remains the treatment of choice for eligible candidates, but the number of transplants worldwide has reached a plateau and is limited by the shortage of donor organs and prolonged wait times. Therefore, LVADs have emerged as an effective and durable form of therapy, and they are currently being used as a bridge to heart transplant, destination lifetime therapy, and cardiac recovery in selected patients. Although this field is evolving rapidly, LVADs are not free of complications, making appropriate patient selection and management by experienced centers imperative for successful therapy. Here, we review current LVAD technology, indications for durable MCS therapy, and strategies for timely referral to advanced heart failure centers before irreversible end-organ abnormalities.

Myocardial Recovery

In this paper, the feasibility of myocardial recovery is analyzed through a literature review. First, the phenomena of remodeling and reverse remodeling are analyzed, approached through the physics of elastic bodies, and the terms myocardial depression and myocardial recovery are defined. Continuing, potential biochemical, molecular, and imaging markers of myocardial recovery are reviewed. Then, the work focuses on therapeutic techniques that can facilitate the reverse remodeling of the myocardium. Left ventricular assist device (LVAD) systems are one of the main ways to promote cardiac recovery. The changes that take place in cardiac hypertrophy, extracellular matrix, cell populations and their structural elements, β-receptors, energetics, and several biological processes, are reviewed. The attempt to wean the patients who experienced cardiac recovery from cardiac assist device systems is also discussed. The characteristics of the patients who will benefit from LVAD are presented and the heterogeneity of the studies performed in terms of patient populations included, diagnostic tests performed, and their results are addressed. The experience with cardiac resynchronization therapy (CRT) as another way to promote reverse remodeling is also reviewed. Myocardial recovery is a phenomenon that presents with a continuous spectrum of phenotypes. There is a need for algorithms to screen suitable patients who may benefit and identify specific ways to enhance this phenomenon in order to help combat the heart failure epidemic.

A Peek at LVADs Pumping to Recovery

Left ventricular assist devices (LVADs) have revolutionized the management of patients with advanced heart failure refractory to medical therapy. Current indications of LVADs include Bridge to Transplantation (BTT), Destination Therapy (DT) for long-term use, Bridge to the Decision (BTD) used as a temporary measure, and lastly Bridge to Recovery (BTR). Here, we briefly review the clinical evidence and the molecular mechanisms behind myocardial recovery following LVAD placement. We also share institutional protocols used at 2 major medical centers in the USA.

LVAD as a Bridge to Remission from Advanced Heart Failure: Current Data and Opportunities for Improvement

Left ventricular assist devices (LVADs) are an established treatment modality for advanced heart failure (HF). It has been shown that through volume and pressure unloading they can lead to significant functional and structural cardiac improvement, allowing LVAD support withdrawal in a subset of patients. In the first part of this review, we discuss the historical background, current evidence on the incidence and assessment of LVAD-mediated cardiac recovery, and out-comes including quality of life after LVAD support withdrawal. In the second part, we discuss current and future opportunities to promote LVAD-mediated reverse remodeling and improve our pathophysiological understanding of HF and recovery for the benefit of the greater HF population.

Long-Term Follow-Up of Mechanical Circulatory Support in Peripartum Cardiomyopathy (PPCM) Refractory to Medical Management: A Multicenter Study

Background: Peripartum cardiomyopathy (PPCM) is a rare, life-threatening form of heart disease, frequently associated with gene alterations and, in some cases, presenting with advanced heart failure. Little is known about ventricular assist device (VAD) implantation in severe PPCM cases. We describe long-term follow-up of PPCM patients who were resistant to medical therapy and received mechanical circulatory support or heart transplant. Methods and results: A total of 13 patients were included with mean follow-up of eight years. Mean age of PPCM onset was 33.7 ± 7.7 years. All patients were initially treated with angiotensin-converting enzyme inhibitors and beta-blockers, and four received bromocriptine. Overall, five patients received VADs (three biventricular, two isolated left ventricular) at median 27 days (range: 3 to 150) following childbirth. Two patients developed drive line infection. Due to the short support time, none of those patients had a stroke or VAD thrombosis. In total, five patients underwent heart transplantation, of which four previously had implanted VADs. Median time to transplantation from PPCM onset was 140 days (range: 43 to 776), and time to transplantation from VAD implantation were 7, 40, 132, and 735 days, respectively. All patients survived until most recent follow up, with the exception of one patient who died following unrelated abdominal surgery two years after PPCM recovery. Conclusions: In patients with severe, life-threatening PPCM refractory to medical management, mechanical circulatory support with or without heart transplantation is a safe therapeutic option.

Physiology of Continuous-Flow Left Ventricular Assist Device Therapy

The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.

Left Ventricular Hemodynamics and Relationship with Myocardial Recovery and Optimization in Patients Supported on CF-LVAD Therapy

BACKGROUND

Despite interest in left ventricular (LV) recovery, there is an absence of data on the relationship between intrinsic LV hemodynamics and both reverse remodeling on continuous flow left ventricular assist device (CF-LVAD) therapy. We hypothesized that markers of intrinsic LV function would be associated with remodeling, optimization, and outcomes.

METHODS

Patients with continuous flow LVADs between 2015 and 2019 who underwent combined left and right heart catheterization (LHC/RHC) ramp protocol at a single institution were enrolled. Patients were stratified by response to CF-LVAD therapy: full responders (FR), partial responders (PR), or non-responders (NR) per Utah-Inova criteria. Hemodynamic data, including LV hemodynamics of peak LV dP/dt and tau (τ) were obtained at each phase. One-year heart failure hospitalization-free survival was the primary endpoint.

RESULTS

Among 61 patients included in the current study 38 (62%) were classified as NR, 14 (23%) PR, and 9 (15%) FR. Baseline LV dP/dt and τ varied by response status (P≤.02) and generally correlated with reverse remodeling on linear regression. Biventricular filling pressures varied with τ and there was an interaction effect of speed on the relationship between τ and PCWP (P=.04). Lastly, τ was a prognostic marker and associated with one-year HF-hospital free survival (OR 1.04, 95%CI 1.00-1.07, P=.02 per ms increase).

CONCLUSIONS

Significant correlations between τ and LV dP/dt and reverse remodeling were noted with tau serving as a prognostic marker. Higher LVAD speed was associated with a greater reliance on LVAD for unloading. Future work should focus on defining the optimal level of LVAD support in relation to LV recovery.

Outcomes of severe peripartum cardiomyopathy and mechanical circulatory support: a case series

Background

We present three cases of severe peripartum cardiomyopathy (PPCM) that required mechanical circulatory supports.

Case presentation

Case 1: A 33-year-old woman developed acute heart failure (AHF) after normal spontaneous delivery. Intra-aortic balloon pump (IABP) was inserted on postpartum day (PD) 10 with a peripartum cardiomyopathy (PPCM), which was withdrawn on PD 30 after medical treatment including anti-prolactin drugs.

Case 2: A 44-year-old woman developed AHF 1 month after vaginal delivery. IABP or extra-corporeal membrane oxygenation (ECMO) was not effective and a biventricular assist device was inserted. It was withdrawn on PD 85 after improvement of left ventricular ejection fraction (LVEF).

Case3: A 37-year-old woman was transferred with a diagnosis of PPCM. Cardiac function unimproved by IABP or ECMO, and a left ventricular assist device was implanted. It was withdrawn on PD 386 after recovery of LVEF.

Conclusion

All the cases with PPCM recovered after mechanical circulatory supports and resumed social lives.

Re-worsening left ventricular ejection fraction after response to cardiac resynchronization therapy

BACKGROUND

Although cardiac resynchronization therapy (CRT) provided functional and clinical improvement in patients with heart failure (HF) and electrical intraventricular conduction disturbances, some patients had re-worsening left ventricular (LV) function after a favorable CRT response. We analyzed the clinical variables and cardiac outcomes associated with this re-worsening LV function after CRT.

METHODS

In this study, 71 patients with CRT response who received CRT between 2006 and 2017 were included. CRT response was defined as a "≥ 10% improvement in LV ejection fraction (LVEF) on follow-up." Patients were classified into two groups: (i) persistent: (n = 48, 68%), defined as those with a CRT response and (ii) re-worsening: (n = 23, 32%), consisting of those who fell out of the definition of a CRT response after an initial CRT response.

RESULTS

Half of the patients in the re-worsening group failed to maintain a CRT response from two years upwards. A longer duration from HF diagnosis to CRT implantation, nonspecific intraventricular conduction delay (NIVCD) on electrocardiogram at CRT implantation, and a lower increased LVEF at initial CRT response were independent predictors for the re-worsening group. Patients in the re-worsening group had a higher incidence rate for HF hospitalization and cardiac deaths, compared with those in the persistent group.

CONCLUSION

One-third of CRT responders experienced re-worsening LVEF, which was associated with poor outcomes. CRT responders with NIVCD, longer HF duration, and a lower increased LVEF at initial CRT response should be monitored with caution.

Characteristics and Outcomes of Patients with Inflammatory Cardiomyopathies Receiving Mechanical Circulatory Support: An STS-INTERMACS Registry Analysis

BACKGROUND

Durable mechanical circulatory support (MCS) therapy improves survival in patients with advanced heart failure. Knowledge regarding the outcomes experienced by patients with inflammatory cardiomyopathy (CM) who receive durable MCS therapy is limited.

METHODS AND RESULTS

We compared patients with inflammatory CM with patients with idiopathic dilated CM enrolled in the STS-INTERMACS registry. Among 19,012 patients, 329 (1.7%) had inflammatory CM and 5978 had idiopathic dilated CM (31.4%). The patients with inflammatory CM were younger, more likely to be White, and women. These patients experienced more preoperative arrhythmias and higher use of temporary MCS. Patients with inflammatory CM had a higher rate of early adverse events (<3 months after device implant), including bleeding, arrhythmias, non-device-related infections, neurologic dysfunction, and respiratory failure. The rate of late adverse events (≥3 months) was similar in the 2 groups. Patients with inflammatory CM had a similar 1-year (80% vs 84%) and 2-year (72% vs 76%, P = .15) survival. Myocardial recovery resulting in device explant was more common among patients with inflammatory CM (5.5% vs 2.3%, P < .001).

CONCLUSIONS

Patients with inflammatory CM who received durable MCS appear to have a similar survival compared with patients with idiopathic dilated CM despite a higher early adverse event burden. Our findings support the use of durable MCS in an inflammatory CM population.

Diagnosis and Management of Myocarditis in Children: A Scientific Statement From the American Heart Association

Myocarditis remains a clinical challenge in pediatrics. Originally, it was recognized at autopsy before the application of endomyocardial biopsy, which led to a histopathology-based diagnosis such as in the Dallas criteria. Given the invasive and low-sensitivity nature of endomyocardial biopsy, its diagnostic focus shifted to a reliance on clinical suspicion. With the advances of cardiac magnetic resonance, an examination of the whole heart in vivo has gained acceptance in the pursuit of a diagnosis of myocarditis. The presentation may vary from minimal symptoms to heart failure, life-threatening arrhythmias, or cardiogenic shock. Outcomes span full resolution to chronic heart failure and the need for heart transplantation with inadequate clues to predict the disease trajectory. The American Heart Association commissioned this writing group to explore the current knowledge and management within the field of pediatric myocarditis. This statement highlights advances in our understanding of the immunopathogenesis, new and shifting dominant pathogeneses, modern laboratory testing, and use of mechanical circulatory support, with a special emphasis on innovations in cardiac magnetic resonance imaging. Despite these strides forward, we struggle without a universally accepted definition of myocarditis, which impedes progress in disease-targeted therapy.

The pyruvate-lactate axis modulates cardiac hypertrophy and heart failure

The metabolic rewiring of cardiomyocytes is a widely accepted hallmark of heart failure (HF). These metabolic changes include a decrease in mitochondrial pyruvate oxidation and an increased export of lactate. We identify the mitochondrial pyruvate carrier (MPC) and the cellular lactate exporter monocarboxylate transporter 4 (MCT4) as pivotal nodes in this metabolic axis. We observed that cardiac assist device-induced myocardial recovery in chronic HF patients was coincident with increased myocardial expression of the MPC. Moreover, the genetic ablation of the MPC in cultured cardiomyocytes and in adult murine hearts was sufficient to induce hypertrophy and HF. Conversely, MPC overexpression attenuated drug-induced hypertrophy in a cell-autonomous manner. We also introduced a novel, highly potent MCT4 inhibitor that mitigated hypertrophy in cultured cardiomyocytes and in mice. Together, we find that alteration of the pyruvate-lactate axis is a fundamental and early feature of cardiac hypertrophy and failure.

Improvement of ejection fraction and mortality in ischaemic heart failure

OBJECTIVE

The frequency and predictors of improvement in left ventricular ejection fraction (LVEF) in ischaemic cardiomyopathy and its association with mortality is poorly understood. We sought to assess the predictors of LVEF improvement ≥10% and its effect on mortality.

METHODS

We compared characteristics of patients enrolled in The Surgical Treatment for Ischaemic Heart Failure (STICH) trial with and without improvement of LVEF ≥10% at 24 months. A logistic regression model was constructed to determine the independent predictors of LVEF improvement. A Cox proportional hazards model was created to assess the independent association of improvement in LVEF ≥10% with mortality.

RESULTS

Of the 1212 patients enrolled in STICH, 618 underwent echocardiographic assessment of LVEF at baseline and 24 months. Of the patients randomised to medical therapy plus coronary artery bypass graft surgery (CABG), 58 (19%) had an improvement in LVEF >10% compared with 51 (16%) patients assigned to medical therapy alone (p=0.30). Independent predictors of LVEF improvement >10% included prior myocardial infarction (OR 0.44, 95% CI: 0.28 to 0.71, p=0.001) and lower baseline LVEF (OR 0.94, 95% CI: 0.91 to 0.97, p<0.001). Improvement in LVEF >10% (HR 0.61, 95% CI: 0.44 to 0.84, p=0.004) and randomisation to CABG (HR 0.72, 95% CI: 0.57 to 0.90, p=0.004) were independently associated with a reduced hazard of mortality.

CONCLUSIONS

Improvement of LVEF ≥10% at 24 months was uncommon in patients with ischaemic cardiomyopathy, did not differ between patients assigned to CABG and medical therapy or medical therapy alone and was independently associated with reduced mortality.

TRIAL REGISTRATION NUMBER

NCT00023595.

Left ventricular assist device recovery: does duration of mechanical support matter?

Heart failure is a widespread condition in the United States that is predicted to significantly increase in prevalence in the next decade. Many heart failure patients are given a left ventricular assist device (LVAD) while they wait for a heart transplant, while those that are not able to undergo a heart transplant may be given an LVAD permanently. However, past studies have observed a small subset of heart failure patients that recovered cardiac function of their native heart after being placed on an LVAD. As a result, some patients have been able to have their LVAD explanted and no longer needed a heart transplant. In this review, we analyzed the data of 15 studies that observed recovery of cardiac function in LVAD patients in order to investigate the effects that duration of LVAD support has on patient outcomes. From our review, we identified that there may be negative consequences of prolonged duration of mechanical support such as myocardial atrophy and abnormal calcium cycling as well as circumstances that may allow for a longer duration of LVAD support such as in patients using a continuous-flow LVAD, non-ischemic cardiomyopathy patients, and the specific pharmacological therapy.

Management of Myocarditis-Related Cardiomyopathy in Adults

Myocarditis is generally a mild and self-limited consequence of systemic infection of cardiotropic viruses. However, patients can develop a temporary or permanent impairment of cardiac function including acute cardiomyopathy with hemodynamic compromise or severe arrhythmias. In this setting, specific causes of inflammation are associated with variable risks of death and transplantation. Recent translational studies suggest that treatments tailored to specific causes of myocarditis may impact clinical outcomes when added to guideline-directed medical care. This review summarizes recent advances in translational research that influence the utility of endomyocardial biopsy for the management of inflammatory cardiomyopathies. Emerging therapies for myocarditis based on these mechanistic hypotheses are entering clinical trials and may add to the benefits of established heart failure treatment.

Recognition and Initial Management of Fulminant Myocarditis: A Scientific Statement From the American Heart Association

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe diffuse cardiac inflammation often leading to death resulting from cardiogenic shock, ventricular arrhythmias, or multiorgan system failure. Historically, FM was almost exclusively diagnosed at autopsy. By definition, all patients with FM will need some form of inotropic or mechanical circulatory support to maintain end-organ perfusion until transplantation or recovery. Specific subtypes of FM may respond to immunomodulatory therapy in addition to guideline-directed medical care. Despite the increasing availability of circulatory support, orthotopic heart transplantation, and disease-specific treatments, patients with FM experience significant morbidity and mortality as a result of a delay in diagnosis and initiation of circulatory support and lack of appropriately trained specialists to manage the condition. This scientific statement outlines the resources necessary to manage the spectrum of FM, including extracorporeal life support, percutaneous and durable ventricular assist devices, transplantation capabilities, and specialists in advanced heart failure, cardiothoracic surgery, cardiac pathology, immunology, and infectious disease. Education of frontline providers who are most likely to encounter FM first is essential to increase timely access to appropriately resourced facilities, to prevent multiorgan system failure, and to tailor disease-specific therapy as early as possible in the disease process.

An in silico twin for epicardial augmentation of the failing heart

Advances in ventricular assist device (VAD) technology for the treatment of end-stage congestive heart failure (CHF) are needed to cope with the increasing numbers of patients that cannot be provided with donor hearts for transplantation. We develop and investigate a novel extravascular VAD technology that provides biventricular, epicardial pressure support for the failing heart. This novel VAD concept avoids blood contact that is accompanied with typical complications such as coagulation and infections. To date, in vivo porcine model results with a prototype of the implant exist, further studies to improve the implant's performance and promote its applicability in humans are needed. In this contribution, we present a personalised functional digital twin of the heart, the vascular system, and the novel VAD technology in terms of a calibrated, customized computational model. The calibration procedure is based on patient-specific measurements and is performed by solving an inverse problem. This in silico model is able to (a) confirm in vivo experimental data, (b) predict healthy and pathologic ventricular function, and (c) assess the beneficial impact of the novel VAD concept to a high level of fidelity. The model shows very good agreement with in vivo data and reliably predicts increases in stroke volume and left ventricular pressure with increasing ventricular support. Furthermore, the digital twin allows insight into quantities that are poorly or not at all amenable in any experimental setup. Conclusively, the model's ability to link integral hemodynamic variables to local tissue mechanical deformation makes it a highly valuable tool for the dimensioning of novel VAD technologies and future treatment strategies in heart failure. The presented in silico twin enhances in vivo studies by facilitating the accessibility and increasing the range of quantities of interest. Because of its flexibility in the assessment of design variants and optimization loops, it may substantially contribute to a reduction of the amount of animal experiments in this and similar settings.

Expanding the Scope of Multimodality Imaging in Durable Mechanical Circulatory Support

An increasing number of patients transition to advanced-stage heart failure refractory to medical therapy. Left ventricular assist systems (LVAS) provide a bridge to candidates awaiting heart transplantation and extended device durability allows permanent implantation referred to as destination therapy. Noninvasive imaging plays a pivotal role in the optimal management of patients implanted with durable mechanical circulatory support (MCS) devices. Several advances require an updated perspective of multi-modality imaging in contemporary LVAS management. First, there has been substantial evolution of devices such as the introduction of the fully magnetically levitated HeartMate 3 pump (Abbott, Abbott Park, Illinois). Second, imaging beyond the device, of the peripheral system, is increasingly recognized as clinically relevant. Third, U.S. Food and Drug Administration recalls have called attention to LVAS complications beyond pump thrombosis that are amenable to imaging-based diagnosis. Fourth, there is increased availability of multimodality imaging, such as computed tomography and positron emission tomography, at many centers across the world. In this review, the authors provide a practical and contemporary approach to multi-modality imaging of current-generation durable MCS devices. As the use of LVAS and other novel MCS devices increases globally, it is critical for clinicians caring for LVAS patients to understand the roles of various imaging modalities in patient evaluation and management.

Cardiovascular Magnetic Resonance in Nonischemic Myocardial Inflammation: Expert Recommendations

This JACC Scientific Expert Panel provides consensus recommendations for an update of the cardiovascular magnetic resonance (CMR) diagnostic criteria for myocardial inflammation in patients with suspected acute or active myocardial inflammation (Lake Louise Criteria) that include options to use parametric mapping techniques. While each parameter may indicate myocardial inflammation, the authors propose that CMR provides strong evidence for myocardial inflammation, with increasing specificity, if the CMR scan demonstrates the combination of myocardial edema with other CMR markers of inflammatory myocardial injury. This is based on at least one T2-based criterion (global or regional increase of myocardial T2 relaxation time or an increased signal intensity in T2-weighted CMR images), with at least one T1-based criterion (increased myocardial T1, extracellular volume, or late gadolinium enhancement). While having both a positive T2-based marker and a T1-based marker will increase specificity for diagnosing acute myocardial inflammation, having only one (i.e., T2-based OR T1-based) marker may still support a diagnosis of acute myocardial inflammation in an appropriate clinical scenario, albeit with less specificity. The update is expected to improve the diagnostic accuracy of CMR further in detecting myocardial inflammation.

Impact of Ischemic Heart Failure Etiology on Cardiac Recovery During Mechanical Unloading

BACKGROUND

Small-scale studies focused mainly on nonischemic cardiomyopathy (NICM) have shown that a subset of left ventricular assist device (LVAD) patients can achieve significant improvement of their native heart function, but the impact of ischemic cardiomyopathy (ICM) has not been specifically investigated. Many patients with acute myocardial infarction are discharged from their index hospitalization without heart failure (HF), only to return much later with overt HF syndrome, mainly caused by chronic remodeling of the noninfarcted region of the myocardium.

OBJECTIVES

This study sought to prospectively investigate the effect of ICM HF etiology on LVAD-associated improvement of cardiac structure and function using NICM as control.

METHODS

Consecutive patients (n = 154) with documented chronic and dilated cardiomyopathy (ICM, n = 61; NICM, n = 93) requiring durable support with continuous-flow LVAD were prospectively evaluated with serial echocardiograms and right heart catheterizations.

RESULTS

In patients supported with LVAD for at least 6 months, we found that 5% of subjects with ICM and 21% of subjects with NICM achieved left ventricular ejection fraction ≥40% (p = 0.034). LV end-diastolic and end-systolic volumes and diastolic function were significantly and similarly improved in patients with ICM and NICM.

CONCLUSIONS

LVAD-associated unloading for 6 months resulted in a substantial improvement in myocardial structure, and systolic and diastolic function in 1 in 20 ICM and 1 in 5 NICM patients. These specific incidence and timeline findings may provide guidance in clinical practice and research design for sequencing and prioritizing advanced HF and heart transplantation therapeutic options in patients with ICM and NICM.

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.

Evolvement of left ventricular assist device: the implications on heart failure management

Heart failure (HF) is a potentially fatal disease that affects increasing number of people worldwide. Although heart transplant is the "gold standard" therapy for HF, due to the limited availability of organs, many patients died when waiting for the transplant. Left ventricular assist device (LVAD), as a mechanical circulatory support, has become a new light for patients with HF. With the technical advancements, LVADs work not only as a bridge to transplant, but also assist heart recovery and even as a destination therapy in long-term treatment. This observation paper reviewed the development of LVAD and its clinical roles. The challenges and possible solutions in nursing care for patients with LVAD at different stage of implantation were discussed. The healthcare professionals could obtain a better understanding about the LVAD treatment for HF patients.

Myocarditis

Viral myocarditis remains a prominent infectious-inflammatory disease for patients throughout the lifespan. The condition presents several challenges including varied modes of clinical presentation, a range of timepoints when patients come to attention, a diversity of approaches to diagnosis, a spectrum of clinical courses, and unsettled perspectives on therapeutics in different patient settings and in the face of different viral pathogens. In this review, we examine current knowledge about viral heart disease and especially provide information on evolving understanding of mechanisms of disease and efforts by investigators to identify and evaluate potential therapeutic avenues for intervention.

Management of Patients With Recovered Systolic Function

Advancements in the treatment of heart failure (HF) with systolic dysfunction have given rise to a new population of patients with improved ejection fraction (EF). The management of this distinct population is not well described due to a lack of consensus on the definition of myocardial recovery, a scarcity of data on the natural history of these patients, and the absence of focused clinical trials. Moreover, an improvement in EF may have different prognostic and management implications depending on the underlying etiology of cardiomyopathy. This can be challenging for the clinician who is approached by a patient inquiring about a reduction of medical therapy after apparent EF recovery. This review explores management strategies for HF patients with recovered EF in a disease-specific format.

Duration of Heart Failure Is an Important Predictor of Outcomes After Mechanical Circulatory Support

BACKGROUND

Heart failure (HF) progression results in worsening functional capacity and end-organ compromise. HF may occur acutely or be associated with a chronic presentation. We hypothesized that the duration of HF affects outcomes after mechanical circulatory support.

METHODS AND RESULTS

A total of 10 730 patients registered in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) who received primary implant of a mechanical circulatory support device were stratified according to the duration of HF symptoms: acute HF (AHF; ≤1 month), sub-AHF (1-12 months), and chronic HF (Cr-HF; ≥ 12 months). AHF patients were younger with a higher proportion of women and white and with a lower prevalence of peripheral vascular disease and history of prior cardiac surgeries. Sixty percent of AHF patients were INTERMACS profile 1 at the time of implantation versus 24% and 13.2% in the sub-AHF and Cr-HF groups, respectively (P=0.0001). Patients with AHF had the highest utilization of biventricular support (14.4%). The estimated survival at 4 years was 58%, 51%, and 45% for the AHF, sub-AHF, and Cr-HF patients (P=0.006). The proportion of patients with AHF who received heart transplantation at 1 year was 29% compared with 22.6% in the patients with Cr-HF. After adjustment for known risk factors of adverse outcome, patients with AHF have a better late phase prognosis compared with patients with Cr-HF (hazard ratio, 0.34; P=0.0003).

CONCLUSIONS

The duration of HF before durable mechanical circulatory support implant is an important variable influencing outcome. Patients with AHF had improved survival at 4 years and higher rates of transplantation at 1 year despite higher acuity of presentation.

The global burden of myocarditis: part 1: a systematic literature review for the Global Burden of Diseases, Injuries, and Risk Factors 2010 study

Myocarditis contributes to the global burden of cardiovascular disease primarily through sudden death and dilated cardiomyopathy. A systematic approach to identify the cardiovascular mortality and major morbidity attributable to myocarditis has not been performed. A writing group convened by the GBD 2010 (Global Burden of Diseases, Injuries and Risk Factors) Study systematically reviewed the world's literature by a manual review of all titles since 1966 on myocarditis identified using Ovid Medline, development of a disease model, and provision of estimates when possible of the incidence, prevalence, risk of death, and major morbidity for the world regions. Accurate population-based estimates of myocarditis incidence and prevalence are not directly available in any world region. However, a model that quantitates the risk of acute death and chronic heart failure following myocarditis was derived from the published data. Using hospital dismissal data, the burden of myocarditis as a percentage of prevalent heart failure varied by age and region from approximately 0.5% to 4.0%. The novel combination of multiple data sources may provide an estimate of the years of life lost and years of life disabled from myocarditis. Pending the integration of these data sources, the burden of dilated cardiomyopathy and myocarditis were reported together in the 2010 GBD report. The 2013 GBD project may refine these estimates with the inclusion of more comprehensive payor databases and more precise case definitions.

Incidence, predictors, and impact on survival of left ventricular systolic dysfunction and recovery in advanced cancer patients

Although left ventricular (LV) dysfunction occurs not uncommonly in the course of cancer therapy, little is known about its natural history and prognostic impact on patients. To investigate the incidence, predictors, and impact on survival of LV systolic dysfunction and recovery during cancer therapy, we conducted a retrospective cohort observational study over 1 year at the University of Texas MD Anderson Cancer Center. We enrolled patients with a decrease in ejection fraction by echocardiography to <50% while undergoing cancer therapy from January 2009 to December 2009. We collected and analyzed their chart data. Of 7,648 patients with echocardiograms in 2009, 366 (4.8%) had ejection fraction <50% and 104 met study criteria. LV systolic dysfunction was associated with cardiotoxic therapy in 53 patients (51%). Recovery occurred in 57 patients (55%) and was independently predicted by younger age, smaller left atrial volume index, and lower B-type natriuretic peptide. At last follow-up, 69 patients (66%) were dead, and 35 (34%) were alive. There was a 20% advantage in 2-year survival among patients with LV systolic recovery compared with those without (95% confidence interval 4% to 41%, p = 0.02). In this retrospective study, LV systolic dysfunction recovery occurred in over half of the patients, appeared independent of cardiotoxic etiology, and associated with a 20% survival benefit at 2 years. Multivariable predictors of recovery are younger age, a small left atrial volume index, and lower B-type natriuretic peptide.

Heart failure with recovered ejection fraction: clinical description, biomarkers, and outcomes

BACKGROUND

We hypothesized that patients with heart failure (HF) who recover left ventricular function (HF-Recovered) have a distinct clinical phenotype, biology, and prognosis compared with patients with HF with reduced ejection fraction (HF-REF) and those with HF with preserved ejection fraction (HF-PEF).

METHODS AND RESULTS

The Penn Heart Failure Study (PHFS) is a prospective cohort of 1821 chronic HF patients recruited from tertiary HF clinics. Participants were divided into 3 categories based on echocardiograms: HF-REF if EF was <50%, HF-PEF if EF was consistently ≥50%, and HF-Recovered if EF on enrollment in PHFS was ≥50% but prior EF was <50%. A significant portion of HF-Recovered patients had an abnormal biomarker profile at baseline, including 44% with detectable troponin I, although in comparison, median levels of brain natriuretic factor, soluble fms-like tyrosine kinase receptor-1, troponin I, and creatinine were greater in HF-REF and HF-PEF patients. In unadjusted Cox models over a maximum follow-up of 8.9 years, the hazard ratio for death, transplantation, or ventricular assist device placement in HF-REF patients was 4.1 (95% confidence interval, 2.4-6.8; P<0.001) and in HF-PEF patients was 2.3 (95% confidence interval, 1.2-4.5; P=0.013) compared with HF-Recovered patients. The unadjusted hazard ratio for cardiac hospitalization in HF-REF patients was 2.0 (95% confidence interval, 1.5-2.7; P<0.001) and in HF-PEF patients was 1.3 (95% confidence interval, 0.90-2.0; P=0.15) compared with HF-Recovered patients. Results were similar in adjusted models.

CONCLUSIONS

HF-Recovered is associated with a better biomarker profile and event-free survival than HF-REF and HF-PEF. However, these patients still have abnormalities in biomarkers and experience a significant number of HF hospitalizations, suggesting persistent HF risk.