The Impella Microaxial Flow Catheter Is Safe and Effective for Treatment of Myocarditis Complicated by Cardiogenic Shock: An Analysis From the Global cVAD Registry

Contemporary optimal therapeutic strategy with escalation/de-escalation of temporary mechanical circulatory support in patients with cardiogenic shock and advanced heart failure in Japan

The utilization of temporary mechanical circulatory support (MCS) in the management of cardiogenic shock is experiencing a notable surge. Acute myocardial infarction remains the predominant etiology of cardiogenic shock, followed by heart failure. Recent findings from the DanGer Shock trial indicate that the percutaneous micro-axial flow pump support, in conjunction with standard care, significantly reduced 6-month mortality in patients with acute myocardial infarction-related cardiogenic shock compared to those receiving standard care alone. However, real-world registry data reveal that the 30-day mortality among patients with acute myocardial infarction-related cardiogenic shock, who received concomitant veno-arterial extracorporeal membrane oxygenation support along with micro-axial flow pump, remain suboptimal. The persistent challenge in the field is how to incorporate, escalate, and de-escalate these temporary MCS to further improve clinical outcomes in such clinical scenarios. This review aims to elucidate the current practices surrounding the escalation and de-escalation of temporary MCS in real-world clinical settings and proposes considerations for future advancements in this critical area.

Chinese Society of Cardiology guidelines on the diagnosis and treatment of adult fulminant myocarditis

Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment.

Percutaneous Mechanical Circulatory Support in Acute Heart Failure Complicated with Cardiogenic Shock

Despite advancements in algorithms concerning the management of cardiogenic shock, current guidelines still lack the adequate integration of mechanical circulatory support devices. In recent years, more and more devices have been developed to provide circulatory with or without respiratory support, when conservative treatment with inotropic agents and vasopressors has failed. Mechanical circulatory support can be contemplated for patients with severe, refractory, or acute-coronary-syndrome-related cardiogenic shock. Through this narrative review, we delve into the differences among the types of currently used devices by presenting their notable advantages and inconveniences. We address the technical issues emerging while choosing the best possible device, temporarily as a bridge to another treatment plan or as a destination therapy, in the optimal timing for each type of patient. We also highlight the diverse implantation and removal techniques to avoid major complications such as bleeding and limb ischemia. Ultimately, we hope to shed some light in the gaps of evidence and the importance of conducting further organized studies around the topic of mechanical circulatory support when dealing with such a high mortality rate.

Mechanical Circulatory Support Systems in Fulminant Myocarditis: Recent Advances and Outlook

Background: Fulminant myocarditis (FM) constitutes a severe and life-threatening form of acute cardiac injury associated with cardiogenic shock. The condition is characterised by rapidly progressing myocardial inflammation, leading to significant impairment of cardiac function. Due to the acute and severe nature of the disease, affected patients require urgent medical attention to mitigate adverse outcomes. Besides symptom-oriented treatment in specialised intensive care units (ICUs), the necessity for temporary mechanical cardiac support (MCS) may arise. Numerous patients depend on these treatment methods as a bridge to recovery or heart transplantation, while, in certain situations, permanent MCS systems can also be utilised as a long-term treatment option. Methods: This review consolidates the existing evidence concerning the currently available MCS options. Notably, data on venoarterial extracorporeal membrane oxygenation (VA-ECMO), microaxial flow pump, and ventricular assist device (VAD) implantation are highlighted within the landscape of FM. Results: Indications for the use of MCS, strategies for ventricular unloading, and suggested weaning approaches are assessed and systematically reviewed. Conclusions: Besides general recommendations, emphasis is put on the differences in underlying pathomechanisms in FM. Focusing on specific aetiologies, such as lymphocytic-, giant cell-, eosinophilic-, and COVID-19-associated myocarditis, this review delineates the indications and efficacy of MCS strategies in this context.

Fulminant myocarditis in adults: a narrative review

Fulminant myocarditis (FM) is an uncommon syndrome characterized by sudden and severe hemodynamic compromise secondary to acute myocardial inflammation, often presenting as profound cardiogenic shock, life-threatening ventricular arrhythmias and/or electrical storm. FM may be refractory to conventional therapies and require mechanical circulatory support (MCS). The immune system has been recognized as playing a pivotal role in the pathophysiology of myocarditis, leading to an increased focus on immunosuppressive treatment strategies. Recent data have highlighted not only the fact that FM has significantly worse outcomes than non-FM, but that prognosis and management strategies of FM are heavily dependent on histological subtype, placing greater emphasis on the role of endomyocardial biopsy in diagnosis. The impact of subtype on severity and prognosis will likewise influence how aggressively the myocarditis is managed, including whether MCS is warranted. Many patients with refractory cardiogenic shock secondary to FM end up requiring MCS, with venoarterial extracorporeal membrane oxygenation demonstrating favorable survival rates, particularly when initiated prior to the development of multiorgan failure. Among the challenges facing the field are the need to more precisely identify immunopathophysiological pathways in order to develop targeted therapies, and the need to better optimize the timing and management of MCS to minimize complications and maximize outcomes.

Enhanced recovery from fulminant myocarditis by treatment with the combined use of the Impella left ventricular assist device with extracorporeal membrane oxygenation: a case series

Background

We experienced two adult cases of fulminant myocarditis with severe cardiogenic shock where Impella left ventricular assist device [left ventricle (LV)-Impella] was concomitantly used with venoarterial extracorporeal membrane oxygenation (V-A ECMO).

Case presentation

A 67-year-old man and a 49-year-old man with fulminant myocarditis were transferred to our hospital with mechanical support of V-A ECMO and IABP. Impella 5.0 and Impella CP were implanted 21 h and 17 h after establishing V-A ECMO for each case. Within 1 week, the patients’ LV function progressively improved. Then the Impellas were withdrawn after discontinuing V-A ECMO. They were discharged from the intensive care unit within the following 8 days.

Conclusions

The optimal introducing timing of LV-Impella is not currently precise. However, this case report suggests that the initiation of LV-Impella within at least 24 h after establishing V-A ECMO may be acceptable for the recovery of cardiac function.

Veno-Arterial Extracorporeal Membrane Oxygenation in Patients with Fulminant Myocarditis: A Review of Contemporary Literature

Fulminant myocarditis is characterized by life threatening heart failure presenting as cardiogenic shock requiring inotropic or mechanical circulatory support to maintain tissue perfusion. There are limited data on the role of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in the management of fulminant myocarditis. This review seeks to evaluate the management of fulminant myocarditis with a special emphasis on the role and outcomes with VA-ECMO use.

Current Landscape of Temporary Percutaneous Mechanical Circulatory Support Technology

Mechanical circulatory support devices provide hemodynamic support to patients who present with cardiogenic shock. These devices work using different mechanisms to provide univentricular or biventricular support. There is a growing body of evidence supporting use of these devices as a goal for cardiac recovery or as a bridge to definitive therapy, but definitive, well-powered studies are still needed. Mechanical circulatory support devices are increasingly used using shock team and protocols, which can help clinicians in decision making, balancing operator and institutional experience and expertise. The aim of this article is to review commercially available mechanical circulatory support devices, their profiles and mechanisms of action, and the evidence available regarding their use.

Efficacy of central extracorporeal life support for patients with fulminant myocarditis and cardiogenic shock

 

OBJECTIVES

Fulminant myocarditis with cardiogenic shock requires extracorporeal life support (ECLS) and has poor outcomes. To improve outcomes, we have converted patients with severely impaired cardiac and multiorgan function from peripheral to central ECLS. In this study, we reviewed these patients’ clinical outcomes and investigated associated factors.

METHODS

We retrospectively studied 70 consecutive patients with fulminant myocarditis under peripheral support from 2006 to 2020. Forty-eight patients underwent surgical conversion to central support, and the remaining patients continued peripheral support. The end point was survival and ventricular assist device-free survival.

RESULTS

More severe pulmonary congestion and multiorgan failure were present in patients with central than peripheral support. Weaning from ECLS was achieved in 95% and 62% of patients with peripheral and central support, respectively. Five-year survival was not significantly different between patients with central and peripheral support (71.2% vs 87.5%, respectively; P = 0.15). However, the ventricular assist device-free survival rate was significantly higher in patients with central than peripheral support (82.2% vs 52.0%, respectively; P = 0.017). A peak creatine kinase-MB level of >180 IU/l, rhythm disturbance and aortic valve closure were detrimental to functional recovery in patients with central support.

CONCLUSIONS

Conversion to central ECLS is feasible and safe in patients with fulminant myocarditis. Patients with severe myocardial injury as shown by a high creatine kinase-MB level, rhythm disturbance and aortic valve closure should be converted to a durable left ventricular assist device.

New Surgical Circulatory Support System Outcomes

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We report the first U.S. experience of the recently approved micro-axial surgical heart pump for the treatment of ongoing cardiogenic shock following acute myocardial infarction (AMICGS), postcardiotomy cardiogenic shock (PCCS), cardiomyopathy including myocarditis, high-risk percutaneous coronary intervention (HRPCI), and coronary artery bypass surgery (HRCABG). Demographic, procedural, hemodynamic, and outcome data were obtained from the manufacturer’s quality database of all Impella 5.5 implants at three centers. Fifty-five patients underwent an Impella 5.5 implant for cardiomyopathy (45%), AMICGS (29%), PCCS (13%), preop CABG (5%), OPCAB (4%), and other (4%). Thirty-five patients (63.6%) were successfully weaned off device with recovery of native heart function. Eleven patients (20.0%) were bridged to another therapy, two patients (3.6%) expired while on support, and in seven patients (12.7%) care was withdrawn. Overall survival was 83.6%. There were no device-related strokes, hemolysis, or limb ischemia observed. Four patients experienced purge sidearm damage, resulting in a pump stop in two patients. The new micro-axial surgical heart pump demonstrated successful clinical and device performance in providing both full hemodynamic support and ventricular unloading for patients with AMICGS, decompensated cardiomyopathy, and high-risk cardiac procedures. In this early U.S. experience, 83.6% of patients survived to explant with 76.1% of these patients recovering native heart function.

Management of Acute Myocarditis and Chronic Inflammatory Cardiomyopathy: An Expert Consensus Document

Myocarditis is an inflammatory disease of the heart that may occur because of infections, immune system activation, or exposure to drugs. The diagnosis of myocarditis has changed due to the introduction of cardiac magnetic resonance imaging. We present an expert consensus document aimed to summarize the common terminology related to myocarditis meanwhile highlighting some areas of controversies and uncertainties and the unmet clinical needs. In fact, controversies persist regarding mechanisms that determine the transition from the initial trigger to myocardial inflammation and from acute myocardial damage to chronic ventricular dysfunction. It is still uncertain which viruses (besides enteroviruses) cause direct tissue damage, act as triggers for immune-mediated damage, or both. Regarding terminology, myocarditis can be characterized according to etiology, phase, and severity of the disease, predominant symptoms, and pathological findings. Clinically, acute myocarditis (AM) implies a short time elapsed from the onset of symptoms and diagnosis (generally <1 month). In contrast, chronic inflammatory cardiomyopathy indicates myocardial inflammation with established dilated cardiomyopathy or hypokinetic nondilated phenotype, which in the advanced stages evolves into fibrosis without detectable inflammation. Suggested diagnostic and treatment recommendations for AM and chronic inflammatory cardiomyopathy are mainly based on expert opinion given the lack of well-designed contemporary clinical studies in the field. We will provide a shared and practical approach to patient diagnosis and management, underlying differences between the European and US scientific statements on this topic. We explain the role of histology that defines subtypes of myocarditis and its prognostic and therapeutic implications.

Myocarditis and inflammatory cardiomyopathy: current evidence and future directions

Inflammatory cardiomyopathy, characterized by inflammatory cell infiltration into the myocardium and a high risk of deteriorating cardiac function, has a heterogeneous aetiology. Inflammatory cardiomyopathy is predominantly mediated by viral infection, but can also be induced by bacterial, protozoal or fungal infections as well as a wide variety of toxic substances and drugs and systemic immune-mediated diseases. Despite extensive research, inflammatory cardiomyopathy complicated by left ventricular dysfunction, heart failure or arrhythmia is associated with a poor prognosis. At present, the reason why some patients recover without residual myocardial injury whereas others develop dilated cardiomyopathy is unclear. The relative roles of the pathogen, host genomics and environmental factors in disease progression and healing are still under discussion, including which viruses are active inducers and which are only bystanders. As a consequence, treatment strategies are not well established. In this Review, we summarize and evaluate the available evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy, with a special focus on virus-induced and virus-associated myocarditis. Furthermore, we identify knowledge gaps, appraise the available experimental models and propose future directions for the field. The current knowledge and open questions regarding the cardiovascular effects associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are also discussed. This Review is the result of scientific cooperation of members of the Heart Failure Association of the ESC, the Heart Failure Society of America and the Japanese Heart Failure Society.

The science of safety: complications associated with the use of mechanical circulatory support in cardiogenic shock and best practices to maximize safety

Acute mechanical circulatory support (MCS) devices are widely used in cardiogenic shock (CS) despite a lack of high-quality clinical evidence to guide their use. Multiple devices exist across a spectrum from modest to complete support, and each is associated with unique risks. In this review, we summarize existing data on complications associated with the three most widely used acute MCS platforms: the intra-aortic balloon pump (IABP), Impella systems, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO). We review evidence from available randomized trials and highlight challenges comparing complication rates from case series and comparative observational studies where a lack of granular data precludes appropriate matching of patients by CS severity. We further offer a series of best practices to help shock practitioners minimize the risk of MCS-associated complications and ensure the best possible outcomes for patients.

Haemodynamic efficacy of microaxial left ventricular assist device in cardiogenic shock: a systematic review and meta-analysis

The Impella percutaneous mechanical circulatory support device is designed to augment cardiac output and reduce left ventricular wall stress and aims to improve survival in cases of cardiogenic shock. In this meta-analysis we investigated the haemodynamic effects of the Impella device in a clinical setting. We systematically searched all articles in PubMed/Medline and Embase up to July 2019. The primary outcomes were cardiac power (CP) and cardiac power index (CPI). Survival rates and other haemodynamic data were included as secondary outcomes. For the critical appraisal, we used a modified version of the U.S. Department of Health and Human Services quality assessment form. The systematic review included 12 studies with a total of 596 patients. In 258 patients the CP and/or CPI could be extracted. Our meta-analysis showed an increase of 0.39 W [95% confidence interval (CI): 0.24, 0.54], (p = 0.01) and 0.22 W/m² (95% CI: 0.18, 0.26), (p < 0.01) for the CP and CPI, respectively. The overall survival rate was 56% (95% CI: 0.50, 0.62), (p = 0.09). The quality of the studies was moderate, mostly due to the presence of confounders. Our study suggests that in patients with cardiogenic shock, Impella support seems effective in augmenting CP(I). This study merely investigates the haemodynamic effectiveness of the Impella device and does not reflect the complete clinical impact for the patient.

Trends in the Incidence of In-Hospital Mortality, Cardiogenic Shock, and Utilization of Mechanical Circulatory Support Devices in Myocarditis (Analysis of National Inpatient Sample Data, 2005-2014)

BACKGROUND

Myocarditis may be associated with hemodynamic instability and portends a poor prognosis when associated with cardiogenic shock (CS). There are limited data available on the incidence of in-hospital mortality, CS, and utilization of mechanical circulatory support (MCS) devices in these patients.

METHODS

We queried the 2005-2014 National Inpatient Sample databases to identify all patients aged >18 years with myocarditis in the United States.

RESULTS

The number of reported cases of myocarditis per 1 million gradually increased from 95 in 2005 to 144 in 2014 (Pfor trend <.01). The trend and incidence of endomyocardial biopsy remained the same despite the increase in clinical diagnosis. Overall, in-hospital mortality was 4.43% of total admissions without a change in overall trend over the study period. We also observed a significant increase in the incidence of CS from 6.94% in 2005 to 11.99% in 2014 (Pfor trend <.01). There was a parallel increase in the utilization of advanced MCS devices during the same time period such as extracorporeal membrane oxygenation or percutaneous cardiopulmonary support (0.32% in 2005 to 2.1% in 2014; P< .01) and percutaneous ventricular assist devices such as Impella/tandem heart (0.176% in 2005 to 1.75% in 2014; P< .01).

CONCLUSION

Although the incidence of myocarditis has increased in the last decade, the in-hospital mortality has remained the same despite increases in the incidence of CS, possibly reflecting the benefits of increased usage of advanced MCS devices. We noted that increasing age, presence of multiple comorbidities and CS were associated with an increase in in-patient mortality.

Mechanical circulatory support with Impella versus intra-aortic balloon pump or medical treatment in cardiogenic shock-a critical appraisal of current data

AIMS

Patients suffering from cardiogenic shock (CS) have a high mortality and morbidity. The Impella percutaneous left-ventricular assist device (LVAD) decreases LV preload, increases cardiac output, and improves coronary blood flow. We aimed to review and meta-analyze available data comparing Impella versus intra-aortic pump (IABP) counterpulsation or medical treatment in CS due to acute myocardial infarction or post-cardiac arrest.

METHODS AND RESULTS

Study-level data were analyzed. Heterogeneity was assessed using the I² statistic. Risk rates were calculated and obtained using a random-effects model (DerSimonian and Laird). Four studies were found suitable for the final analysis, including 588 patients. Primary endpoint was short-term mortality (in-hospital or 30-day mortality). In a meta-analysis of four studies comparing Impella versus control, Impella was not associated with improved short-term mortality (in-hospital or 30-day mortality; RR 0.84; 95% CI 0.57-1.24; p = 0.38; I² 55%). Stroke risk was not increased (RR 1.00; 95% CI 0.36-2.81; p = 1.00; I²2 0%), but risk for major bleeding (RR 3.11 95% CI 1.50-6.44; p = 0.002; I² 0%) and peripheral ischemia complications (RR 2.58; 95% CI 1.24-5.34; p = 0.01; I² 0%) were increased in the Impella group.

CONCLUSION

In patients suffering from severe CS due to AMI, the use of Impella is not associated with improved short-time survival but with higher complications rates compared to IABP and medical treatment. Better patient selection avoiding Impella implantation in futile situations or in possible lower risk CS might be necessary to elucidate possible advantages of Impella in future studies.