Temporary Mechanical Circulatory Support in Acute Heart Failure

Ventricular Septal Rupture After Myocardial Infarction: JACC Focus Seminar 3/5

Ventricular septal rupture remains a dreadful complication of acute myocardial infarction. Although less commonly observed than during the prethrombolytic era, the condition remains complex and is often associated with refractory cardiogenic shock and death. Corrective surgery, although superior to medical treatment, has been associated with high perioperative morbidity and mortality. Transcatheter closure techniques are less invasive to surgery and offer a valuable alternative, particularly in patients with cardiogenic shock. In these patients, percutaneous mechanical circulatory support represents a novel opportunity for immediate stabilization and preserved end-organ function. Multimodality imaging can identify favorable septal anatomy for the most appropriate type of repair. The heart team approach will define optimal timing for surgery vs percutaneous repair. Emerging concepts are proposed for a deferred treatment approach, including orthotropic heart transplantation in ideal candidates. Finally, for futile situations, palliative care experts and a medical ethics team will provide the best options for end-of-life clinical decision making.

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.

Delayed surgical repair via right ventricular approach with Impella and extracorporeal life support in post-myocardial infarction ventricular septal defect: A case report

INTRODUCTION

Post-myocardial infarction ventricular septal defect (PIVSD) is a life-threatening mechanical complication of acute myocardial infarction (AMI). Delayed elective surgical repair can be considered in patients who respond well to aggressive heart failure therapy. Impella has been reported as a bridge to allow the deferment of surgery for PIVSD.

PRESENTATION OF CASE

This report describes our case of a 62-year-old male with PIVSD and cardiogenic shock. Impella was placed to ensure hemodynamic stability. Subsequently, right heart failure was suspected to be caused by insufficient circulatory support from Impella alone. Emergency surgery was considered, but it was high risk and only a few days had passed since the onset. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) was implanted to treat right heart failure and delay surgical repair as long as possible. Six days after Impella implantation, the patient underwent a successful surgical repair via the right ventricle without associated adverse events.

DISCUSSION

Impella support can be insufficient for critically ill patients such as those with a larger ventricular septal defect and involvement of right ventricular function. VA-ECMO was implanted to support circulation, reduce the preload in the right ventricle, and avoid shunt inversion induced by increasing Impella flow. The patient was able to undergo a successful delayed repair with VA-ECMO at least one week after the onset of the AMI with hemodynamic stability and no associated adverse events.

CONCLUSION

Additional VA-ECMO could help patients who fail to bridge to surgery with Impella to avoid emergency surgery, leading to successful delayed surgical repair.

Guide to Temporary Mechanical Support in Cardiogenic Shock: Choosing Wisely

Cardiogenic shock is a multisystem pathology that carries a high mortality rate, and initial pharmacotherapies include the use of vasopressors and inotropes. These agents can increase myocardial oxygen consumption and decrease tissue perfusion that can oftentimes result in a state of refractory cardiogenic shock for which temporary mechanical circulatory support can be considered. Numerous support devices are available, each with its own hemodynamic blueprint. Defining a patient's hemodynamic profile and understanding the phenotype of cardiogenic shock is important in device selection. Careful patient selection incorporating a multidisciplinary team approach should be utilized.

Emerging Racial Differences in Heart Transplant Waitlist Outcomes for Patients on Temporary Mechanical Circulatory Support

Temporary mechanical circulatory support (tMCS) is increasingly used for patients awaiting heart transplantation. Although examples of systemic inequity in cardiac care have been described, biases in tMCS use are not well characterized. This study explores the racial disparities in tMCS use and waitlist outcomes. The United Network for Organ Sharing database was used to identify adults listed for first-time heart transplantation from 2015 to 2021. White and non-White patients on extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary left ventricular assist device were identified. Waitlist outcomes of mortality, transplantation, and delisting were analyzed by race using competing risks regression. The effect of the new heart allocation system was also assessed. A total of 16,811 patients were included in this study, with 10,377 self-identifying as White and 6,434 as non-White. White patients were more often male, privately ensured, and had less co-morbidities (p <0.05). tMCS use was found to be significantly higher in non-White patients (p <0.001). Among those on tMCS, non-White patients were more likely to be delisted because of illness (subhazard ratio 1.34 [1.09 to 1.63]) and less likely to die while on the waitlist (subhazard ratio 0.76 [0.61 to 0.93]). This disparity was not present before the implementation of the new heart allocation system. tMCS use was proportional to the risk factors identified in the non-White cohort. After the implementation of the new heart allocation system, White patients were more likely to die, whereas non-White patients were more likely to be delisted. Further work is needed to determine the causes of and potential solutions for disparities in the waitlist outcomes.

Effect of peri-operative intra-aortic balloon pump in patients undergoing coronary artery bypass grafting on outcomes in a resource limited setting

INTRODUCTION

Intra-aortic balloon pump (IABP) insertion for diminished myocardial function is standard of care in cardiac surgery. Previous studies have suggested a possible benefit to IABP support before surgery with regards to outcomes and complications. However, there are conflicts with other studies suggesting no significant benefit. Optimal time of insertion, whether preoperative or perioperative (intra-operative and post-operative), has yet to be defined.

METHODOLOGY

A retrospective, hospital records-based chart review was conducted for patients admitted to our center from January 2015 to December 2019 for coronary bypass surgery necessitating IABP insertion. Cases were stratified according to the timing of insertion and analyzed according to surgical outcomes and complication rates.

RESULTS

Out of 97 patients, 84.5% underwent preoperative IABP insertion while 15.5% of patients received perioperative (Intra-operative or post-operative) insertion. In-hospital mortality was significantly higher in patients with perioperative IABP insertion as compared to the preoperative group (60% vs 20.7%, p = 0.003). However, there were no significant differences between 30-day readmission rates in the two groups (9.8% vs 6.7%, p = 1.000). Length of stay was also higher in patients with preoperative insertion of IABP (p = 0.032), with no significant difference in ICU stay (p = 0.107). Perioperative IABP patients had higher rates of arrhythmias (46.7%, p = 0.042) and reopening of patient (33.3%, p = 0.028).

CONCLUSION

Our study shows improved mortality in patients with preoperatively inserted IABP. This may be beneficial for high-risk patients undergoing CABG surgery. Expanding the use of IABP before CABG in third world countries such as Pakistan may improve overall survival for patients.

Ambulatory short-term mechanical circulatory support: facilitates recovery and prepares patients for definitive therapy

Short-term mechanical circulatory support (ST-MCS) devices have been traditionally deployed in patients with cardiogenic shock, advanced heart failure, cardiovascular collapse, and cardiorespiratory failure. Limitations of the mechanical support devices are typically related to mobility of the patient since the access is frequently through femoral vasculature. This limits the time the patient can be supported by mechanical circulatory support (MCS). We describe deployment of ST-MCS using alternate access such as the subclavian/axillary artery that facilitates ambulation of the patient. These include the deployment of intra-aortic balloon pump (IABP) through the subclavian artery, Impella pump through the axillary/subclavian artery, and extracorporeal membrane oxygenation (ECMO) using the subclavian artery and jugular vein.

The Use of Cardioprotective Devices and Strategies in Patients Undergoing Percutaneous Procedures and Cardiac Surgery

In the United States, about one million people are seen to visit the operating theater for cardiac surgery annually. However, nearly half of these visits result in complications such as renal, neurological, and cardiac injury of varying degrees. Historically, many mechanisms and approaches have been explored in attempts to reduce injuries associated with cardiac surgery and percutaneous procedures. Devices such as cardioplegia, mechanical circulatory support, and other methods have shown promising results in managing and preventing life-threatening cardiac-surgery-related outcomes such as heart failure and cardiogenic shock. Comparably, cardioprotective devices such as TandemHeart, Impella family devices, and venoarterial extracorporeal membrane oxygenation (VA-ECMO) have also been proven to show significant cardioprotection through mechanical support. However, their use as interventional agents in the prevention of hemodynamic changes due to cardiac surgery or percutaneous interventions has been correlated with adverse effects. This can lead to a rebound increased risk of mortality in high-risk patients who undergo cardiac surgery. Further research is necessary to delineate and stratify patients into appropriate cardioprotective device groups. Furthermore, the use of one device over another in terms of efficacy remains controversial and further research is necessary to assess device potential in different settings. Clinical research is also needed regarding novel strategies and targets, such as transcutaneous vagus stimulation and supersaturated oxygen therapy, aimed at reducing mortality among high-risk cardiac surgery patients. This review explores the recent advances regarding the use of cardioprotective devices in patients undergoing percutaneous procedures and cardiac surgery.

Recent advances in biological pumps as a building block for bioartificial hearts

The field of biological pumps is a subset of cardiac tissue engineering and focused on the development of tubular grafts that are designed generate intraluminal pressure. In the simplest embodiment, biological pumps are tubular grafts with contractile cardiomyocytes on the external surface. The rationale for biological pumps is a transition from planar 3D cardiac patches to functional biological pumps, on the way to complete bioartificial hearts. Biological pumps also have applications as a standalone device, for example, to support the Fontan circulation in pediatric patients. In recent years, there has been a lot of progress in the field of biological pumps, with innovative fabrication technologies. Examples include the use of cell sheet engineering, self-organized heart muscle, bioprinting and in vivo bio chambers for vascularization. Several materials have been tested for biological pumps and included resected aortic segments from rodents, type I collagen, and fibrin hydrogel, to name a few. Multiple bioreactors have been tested to condition biological pumps and replicate the complex in vivo environment during controlled in vitro culture. The purpose of this article is to provide an overview of the field of the biological pumps, outlining progress in the field over the past several years. In particular, different fabrication methods, biomaterial platforms for tubular grafts and examples of bioreactors will be presented. In addition, we present an overview of some of the challenges that need to be overcome for the field of biological pumps to move forward.

A Holistic View of Advanced Heart Failure

Advanced heart failure (HF) may occur at any level of left ventricular (LV) ejection fraction (LVEF). The latter, which is widely utilized for the evaluation of LV systolic performance and treatment guidance of HF patients, is heavily influenced by LV size and geometry. As the accurate evaluation of ventricular systolic function and size is crucial in patients with advanced HF, the LVEF should be supplemented or even replaced by more specific indices of LV function such as the systolic strain and cardiac power output and size such as the LV diastolic diameters and volumes. Conventional treatment (cause eradication, medications, devices) is often poorly tolerated and fails and advanced treatment (mechanical circulatory support [MCS], heart transplantation [HTx]) is required. The effectiveness of MCS is heavily dependent on heart size, whereas HTx which is effective in the vast majority of the cases is limited by the small donor pool. Expanding the MCS indications to include patients with small ventricles as well as the HTx donor pool are major challenges in the management of advanced HF.

Rational and Initiative of the Impella in Cardiac Surgery (ImCarS) Register Platform

OBJECTIVES

 Cardiac support systems are being used increasingly more due to the growing prevalence of heart failure and cardiogenic shock. Reducing cardiac afterload, intracardiac pressure, and flow support are important factors. Extracorporeal membrane oxygenation (ECMO) and intracardiac microaxial pump systems (Impella) as non-permanent MCS (mechanical circulatory support) are being used increasingly.

METHODS

 We reviewed the recent literature and developed an international European registry for non-permanent MCS.

RESULTS

 Life-threatening conditions that are observed preoperatively often include reduced left ventricular function, systemic hypoperfusion, myocardial infarction, acute and chronic heart failure, myocarditis, and valve vitia. Postoperative complications that are commonly observed include severe systemic inflammatory response, ischemia-reperfusion injury, trauma-related disorders, which ultimately may lead to low cardiac output (CO) syndrome and organ dysfunctions, which necessitates a prolonged ICU stay. Choosing the appropriate device for support is critical. The management strategies and complications differ by system. The "heart-team" approach is inevitably needed.However despite previous efforts to elucidate these topics, it remains largely unclear which patients benefit from certain systems, when is the right time to initiate (MCS), which support system is appropriate, what is the optimal level and type of support, which therapeutic additive and supportive strategies should be considered and ultimately, what are the future prospects and therapeutic developments.

CONCLUSION

 The European cardiac surgical register ImCarS has been established as an IIT with the overall aim to evaluate data received from the daily clinical practice in cardiac surgery. Interested colleagues are cordially invited to join the register.

CLINICAL REGISTRATION NUMBER

 DRKS00024560.

POSITIVE ETHICS VOTE

 AZ 246/20 Faculty of Medicine, Justus-Liebig-University-Gießen.

Mechanical Circulatory Support: Primer for Consultant Specialists

Mechanical life support therapies exist in many forms to temporarily replace the function of vital organs. Generally speaking, these tools are supportive therapy to allow for organ recovery but, at times, require transition to long-term mechanical support. This review will examine nonrenal extracorporeal life support for cardiac and pulmonary support as well as other mechanical circulatory support options. This is intended as a general primer and overview to assist nephrologist consultants participating in the care of these critically ill patients who often experience acute renal injury as a result of cardiopulmonary shock and from their exposure to mechanical circulatory support.

The Impact of Noninvasive Ventilator Assisted Ventilation Nursing Combined with Mechanical Vibration on the Level of Heart Failure Indexes in ICU Patients with Acute Heart Failure

The acute attack of acute heart failure or the continuous deterioration of cardiac function leads to a series of changes such as reduced cardiac contractility, increased cardiac load, and a sudden drop of acute cardiac output, which eventually cause pulmonary circulation congestion and acute dyspnea due to acute pulmonary congestion. To observe the impact of noninvasive ventilator-assisted ventilation nursing combined with mechanical vibration on the level of heart failure indexes in intensive care unit (ICU) patients with acute heart failure, 120 patients with acute heart failure who were treated in the ICU ward of our hospital from September 2018 to March 2021 were selected, and the qualified subjects were divided into two groups according to the 1 : 1 principle by a simple random method. 120 patients were given conventional symptomatic treatment and noninvasive ventilator-assisted ventilation. The control group received conventional nursing intervention, and the observation group was given noninvasive ventilator-assisted ventilation nursing and mechanical vibration intervention. The respiratory system indexes, heart rate, blood pressure, central venous pressure, N-terminal B-type natriuretic peptide precursor (NT-proBNP), cardiac troponin T (cTnT), and cardiac function indexes of the two groups of patients are recorded, and the prognosis of the two groups is compared. After intervention, the partial pressure of oxygen (PaO2) and blood oxygen saturation (SpO2) in the two groups were higher than those before intervention, while the partial pressure of carbon dioxide (PaCO2), respiration (RR), heart rate, blood pressure, and central venous pressure were lower than those before intervention (P < 0.05). Compared with the control group, PaO2, SpO2, systolic blood pressure, diastolic blood pressure, and central venous pressure of the observation group after intervention were significantly higher, while PaCO2, RR, and heart rate were significantly lower (P < 0.05). Compared with the control group, the LVEF of the observation group after intervention was significantly higher, while NT-proBNP, cTnT, LVESD, and LVEDD were markedly lower (P < 0.05). The ventilation time and ICU hospitalization time in the observation group were shorter than those in the control group, and the pulmonary infection rate was lower than in the control group. The remission time of infection in patients with pulmonary infection was shorter than that in the control group. When comparing the 28d mortality rate with the control group, the difference was not statistically significant (P > 0.05). Noninvasive ventilator-assisted ventilation nursing combined with mechanical vibration can improve hypoxemia symptoms and heart function, stabilize hemodynamics, shorten the course of disease and reduce the occurrence of lung infections for those patients with acute heart failure in the ICU.

Cardiogenic Shock and the Use of Percutaneous Mechanical Assist Devices

Percutaneous mechanical assist devices are used in patients with cardiogenic shock. The purpose of this article is to familiarize critical care nurses with the various types of percutaneous mechanical assist devices, including the intra-aortic balloon pump, the Impella device, extracorporeal membrane oxygenation, and the TandemHeart device. Each type of device requires specific nursing care. In a patient with cardiogenic shock, the monitoring, care, and interventions provided by an experienced critical care nurse can make the difference between survival and death.

Acute Circulatory Collapse and Advanced Therapies in Patients with COVID-19 Infection

In the current era of the COVID-19 pandemic, intensive care patients with COVID-19 often develop respiratory failure and acute respiratory distress syndrome. While less frequent, acute circulatory collapse, with or without respiratory failure, has its own management challenges and nuances. Early identification of acute circulatory collapse requires appropriate imaging, particularly echocardiography, and precise diagnosis of cardiogenic shock using a Swan-Ganz catheter. Escalation to mechanical circulatory support (MCS), such as an intra-aortic balloon pump, Impella, and extracorporeal membrane oxygenation, has been useful in patients with acute circulatory collapse from COVID-19. This condition is associated with high morbidity and mortality, but early recognition of appropriate candidates for specific treatment strategies and escalation to MCS might improve outcomes.

Minimally Invasive Off-Pump Technique for Temporary Left Ventricular Support

Use of short-term mechanical circulatory support (MCS) for cardiogenic shock has rapidly increased. Most common initial MCS strategies entail institution of peripheral extracorporeal membrane oxygenation (ECMO) or temporary ventricular assist devices. For patients with anatomically small peripheral arteries or insufficient circulatory support, sternotomy and central cannulation techniques may be necessary. These invasive approaches are associated with increased risk of bleeding and other significant complications. We describe a minimally invasive, off-pump technique to provide adequate hemodynamic support and left ventricular unloading, allowing early postoperative ambulation, and ability to easily provide additional right ventricular/ECMO support if needed.

Evaluation of a Novel Left Ventricular Assist Device for Resuscitation in an Animal Model of Ventricular Fibrillation Cardiac Arrest

We evaluated an independently developed novel percutaneous implantable left ventricular assist device for resuscitation in a pig model of ventricular fibrillation cardiac arrest. The model was established in 10 domestic pigs by blocking the anterior descending coronary artery with a balloon after anesthesia. With ventilator-assisted ventilation, the independently developed percutaneous implantable left ventricular assist device was inserted via the femoral artery to assist circulation. According to whether effective circulatory support was achieved, the pigs were randomly divided into an experimental group and a control group. The experimental group was subjected to insertion of the assist device and received continuous circulatory support. The control group underwent insertion of the assist device; however, it did not start it within 15 minutes. For all animals, if successful rescue was achieved (sinus rhythm restoration within 15 minutes and maintenance for over 5 minutes), circulatory support was stopped, and the arterial blockage was removed. If sinus rhythm was not restored within 15 minutes, electric defibrillation, adrenaline injection, and removal of the arterial blockage were performed, and circulatory support was provided until sinus rhythm recovered. A determination of failed rescue was made when sinus rhythm was not restored after 1 hour. All successfully rescued animals were fed for 1 week. There were no significant differences in baseline data between the groups. All animals underwent successful novel left ventricular assist device implantation through the femoral artery. The rescue rate was significantly higher in the experimental group than in the control group (80% vs. 0%, [Formula: see text]). All successfully rescued animals survived after 1 week of feeding, and no eating or movement abnormalities were observed. We conclude that this independently developed percutaneous implantable left ventricular assist device can be conveniently and rapidly implanted through the femoral artery and can maintain basic circulatory perfusion during resuscitation in an animal model of cardiac arrest.

Mechanical Circulatory Support as a Bridge to Definitive Treatment in Post-Infarction Ventricular Septal Rupture

Ventricular septal rupture (VSR) represents a rare complication of acute myocardial infarction, often presenting with cardiogenic shock and associated with high in-hospital mortality despite prompt intervention. Although immediate surgery is recommended for patients who cannot be effectively stabilized, the ideal timing of intervention remains controversial. Mechanical circulatory support (MCS) may allow hemodynamic stabilization and delay definitive treatment even in critical patients. However, the interactions between MCS and VSR pathophysiology as well as potentially related adverse effects remain unclear. A systematic review was performed, from 2000 onward, to identify reports describing MCS types, effects, complications, and outcomes in the pre-operative VSR-related setting. One hundred eleven studies (2,440 patients) were included. Most patients had well-known negative predictors (e.g., cardiogenic shock, inferior infarction). Almost all patients had intra-aortic balloon pumps, with additional MCS adopted in 129 patients (77.5% being venoarterial extracorporeal membrane oxygenation). Mean MCS bridging time was 6 days (range: 0 to 23 days). In-hospital mortality was 50.4%, with the lowest mortality rate in the extracorporeal membrane oxygenation group (29.2%). MCS may enhance hemodynamic stabilization and delayed VSR treatment. However, the actual effects and interaction of the MCS-VSR association should be carefully assessed to avoid further complications or incorrect MCS-VSR coupling.

Racial Disparities in the Utilization and Outcomes of Temporary Mechanical Circulatory Support for Acute Myocardial Infarction-Cardiogenic Shock

Racial disparities in utilization and outcomes of mechanical circulatory support (MCS) in patients with acute myocardial infarction-cardiogenic shock (AMI-CS) are infrequently studied. This study sought to evaluate racial disparities in the outcomes of MCS in AMI-CS. The National Inpatient Sample (2012–2017) was used to identify adult AMI-CS admissions receiving MCS support. MCS devices were classified as intra-aortic balloon pump (IABP), percutaneous left ventricular assist device (pLVAD) or extracorporeal membrane oxygenation (ECMO). Self-reported race was classified as white, black and others. Outcomes included in-hospital mortality, hospital length of stay and discharge disposition. During this period, 90,071 admissions were included with white, black and other races constituting 73.6%, 8.3% and 18.1%, respectively. Compared to white and other races, black race admissions were on average younger, female, with greater comorbidities, and non-cardiac organ failure (all p < 0.001). Compared to the white race (31.3%), in-hospital mortality was comparable in black (31.4%; adjusted odds ratio (aOR) 0.98 (95% confidence interval (CI) 0.93–1.05); p = 0.60) and other (30.2%; aOR 0.96 (95% CI 0.92–1.01); p = 0.10). Higher in-hospital mortality was noted in non-white races with concomitant cardiac arrest, and those receiving ECMO support. Black admissions had longer lengths of hospital stay (12.1 ± 14.2, 10.3 ± 11.2, 10.9 ± 1.2 days) and transferred less often (12.6%, 14.2%, 13.9%) compared to white and other races (both p < 0.001). In conclusion, this study of AMI-CS admissions receiving MCS devices did not identify racial disparities in in-hospital mortality. Black admissions had longer hospital stay and were transferred less often. Further evaluation with granular data including angiographic and hemodynamic parameters is essential to rule out racial differences.

Left Ventricular Assist Device-Related Complications

Left ventricular assist device (LVAD) has emerged as a safe, durable, and revolutionary therapy for end-stage heart failure patients. Despite the appearance of newer-generation devices that have improved patient outcomes, the burden of adverse events remains significant. Although the survival rate for patients with LVAD is appreciated to be 81% at 1 year and 70% at 2 years, the incidence of adverse events is also high. Over time, both early and late postimplant complications have diminished in terms of prevalence and impact; however, complications, such as infections, bleeding, right heart failure, pump thrombosis, aortic insufficiency, or stroke, continue to represent a challenge for the practitioner. Therefore, the aim of this review is to highlight the most recent data regarding the current use of LVAD in the treatment of end-stage heart failure, with a specific focus on LVAD-related complications, in order to improve device-related outcomes. It will also revise how to mitigate the risk and how to approach specific adverse events. Withal, understanding the predisposing risk factors associated with postimplant complications, early recognition and appropriate treatment help to significantly improve the prognosis for patients with end-stage heart failure.