Case Report First-in-Man Method Description: Left Ventricular Unloading With iVAC2L During Veno-Arterial Extracorporeal Membrane Oxygenation: From Veno-Arterial Extracorporeal Membrane Oxygenation to ECMELLA to EC-iVAC®

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.

Year in review: Highlights in ECLS Innovation and Technology, Anno 2022-2023

BACKGROUND

In the field of extracorporeal life support (ECLS), the rapid influx of novel technologies and innovative techniques presents an ongoing challenge for professionals to stay informed about these advancements. To address this issue and ensure the ECLS community remains up-to-date, we have compiled a concise overview of recent technological innovations in ECLS.

PURPOSE

This overview focuses primarily on academically investigated and reported advancements in the ECLS domain. It underscores the importance of transparent communication regarding technological limitations in healthcare and advocates for collaboration between medical professionals and engineers to elevate patient care.

RESEARCH DESIGN

This manuscript presents a compilation of recent technological advancements in ECLS, with an emphasis on innovations that have been academically explored and documented. The research approach involves gathering information from scholarly sources, reports, and studies to provide a comprehensive overview.

STUDY SAMPLE

The study sample comprises a diverse range of recent technological innovations in the field of extracorporeal life support (ECLS). These innovations span various aspects of ECLS technology and have been investigated and reported on within the academic literature.

ANALYSIS

Data collection involved systematically reviewing academic literature, reports, and studies related to recent technological advancements in ECLS. The collected information was then analyzed to identify common trends, notable developments, and the impact of these innovations on patient care.

RESULTS

The compilation highlights several significant technological innovations within the ECLS domain. Notable advancements include the development of new dual lumen cannulae, innovative devices for left ventricular (LV) unloading, lightweight ECMO transport systems, streamlined driving consoles to facilitate patient mobility, intricate systems for extracorporeal cardiopulmonary resuscitation (ECPR), standardized driving consoles for networking, and non-invasive circuit pressure monitoring. Some of these innovations have obtained regulatory approvals for distribution in the United States and/or authorization for the European market.

CONCLUSIONS

The manuscript underscores the critical role of collaboration between clinicians, researchers, and industry in driving recent technological innovations within the ECLS field. It emphasizes the necessity of open communication about technological limitations and the potential for repurposing established technologies in novel ways. However, the resourcefulness of physicians in repurposing devices requires validation through comprehensive scientific and technical investigation. Thus, fostering broader collaboration among stakeholders is recommended to ensure the rigorous evaluation and validation of new applications for established ECLS devices.

Venting during venoarterial extracorporeal membrane oxygenation

Cardiogenic shock and cardiac arrest contribute pre-dominantly to mortality in acute cardiovascular care. Here, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has emerged as an established therapeutic option for patients suffering from these life-threatening entities. VA-ECMO provides temporary circulatory support until causative treatments are effective and enables recovery or serves as a bridging strategy to surgical ventricular assist devices, heart transplantation or decision-making. However, in-hospital mortality rate in this treatment population is still around 60%. In the recently published ARREST trial, VA-ECMO treatment lowered mortality rate in patients with ongoing cardiac arrest due to therapy refractory ventricular fibrillation compared to standard advanced cardiac life support in selected patients. Whether VA-ECMO can reduce mortality compared to standard of care in cardiogenic shock has to be evaluated in the ongoing prospective randomized studies EURO-SHOCK (NCT03813134) and ECLS-SHOCK (NCT03637205). As an innate drawback of VA-ECMO treatment, the retrograde aortic flow could lead to an elevation of left ventricular (LV) afterload, increase in LV filling pressure, mitral regurgitation, and elevated left atrial pressure. This may compromise myocardial function and recovery, pulmonary hemodynamics—possibly with concomitant pulmonary congestion and even lung failure—and contribute to poor outcomes in a relevant proportion of treated patients. To overcome these detrimental effects, a multitude of venting strategies are currently engaged for both preventive and emergent unloading. This review aims to provide a comprehensive and structured synopsis of existing venting modalities and their specific hemodynamic characteristics. We discuss in detail the available data on outcome categories and complication rates related to the respective venting option.

Graphical abstract

Effectiveness and Safety of a Prolonged Hemodynamic Support by the IVAC2L System in Healthy and Cardiogenic Shock Pigs

Background

Mechanical circulatory supports are used in case of cardiogenic shock (CS) refractory to conventional therapy. Several devices can be employed, but are limited by their availability, benefit risk-ratio, and/or cost.

Aims

To investigate the feasibility, safety, and effectiveness of a long-term support by a new available device (IVAC2L) in pigs.

Methods

Experiments were carried out in male pigs, divided into healthy (n = 6) or ischemic CS (n = 4) groups for a median support time of 34 and 12 h, respectively. IVAC2L was implanted under fluoroscopic and TTE guidance under general anesthesia. CS was induced by surgical ligation of the left anterior descending artery. An ipsilateral lower limb reperfusion was created with the Solopath® system. Reperfusion was started after 1 h of support in healthy pigs and upon IVAC2L insertion in CS pigs. Hemodynamic and biological parameters were monitored before and during the whole period of support in each group.

Results

Occurrence of an ipsilateral lower limb ischemia was systematic in healthy and CS pigs in a few minutes after IVAC2L implantation, and could be reversed by the arterial reperfusion, as demonstrated by distal transcutaneous pressure in oxygen (TcPO₂) and lactate normalization. IVAC2L support decreased pulmonary capillary wedge pressure (PCWP) (15.3 ± 0.3 vs. 7.5 ± 0.9 mmHg, p < 0.001), increased systolic blood pressure (SBP) (70 ± 4.5 vs. 101.3 ± 3.1 mmHg, p < 0.01), and cardiac output (CO) (4.0 ± 0.3 vs. 5.2 ± 0.6 l/min, p < 0.05) in CS pigs; at CS onset and after 12 h of support, without effects on heart rate or pulmonary artery pressure (PAP). Non-sustained ventricular arrhythmias were frequent at implantation (50%). A non-significant hemolysis was observed under support in CS pigs. Bleedings were frequent at the insertion and/or operating sites (30%).

Conclusion

Long-term support by IVAC2L is feasible and associated with a significant hemodynamic improvement in a porcine model. These preclinical data open the door for a study of IVAC2L in human ischemic CS, keeping in mind the need for systematic reperfusion of the lower limb and the associated risk of bleeding.

The "TIDE"-Algorithm for the Weaning of Patients With Cardiogenic Shock and Temporarily Mechanical Left Ventricular Support With Impella Devices. A Cardiovascular Physiology-Based Approach

Objectives: Mechanical circulatory support (MCS) is often required to stabilize therapy-refractory cardiogenic shock patients. Left ventricular (LV) unloading by mechanical ventricular support (MVS) via percutaneous devices, such as with Impella® axial pumps, alone or in combination with extracorporeal life support (ECLS, ECMELLA approach), has emerged as a potential clinical breakthrough in the field. While the weaning from MCS is essentially based on the evaluation of circulatory stability of patients, weaning from MVS holds a higher complexity, being dependent on bi-ventricular function and its adaption to load. As a result of this, weaning from MVS is mostly performed in the absence of established algorithms. MVS via Impella is applied in several cardiogenic shock etiologies, such as acute myocardial infarction (support over days) or acute fulminant myocarditis (prolonged support over weeks, PROPELLA). The time point of weaning from Impella in these cohorts of patients remains unclear. We here propose a novel cardiovascular physiology-based weaning algorithm for MVS.

Methods: The proposed algorithm is based on the experience gathered at our center undergoing an Impella weaning between 2017 and 2020. Before undertaking a weaning process, patients must had been ECMO-free, afebrile, and euvolemic, with hemodynamic stability guaranteed in the absence of any inotropic support. The algorithm consists of 4 steps according to the acronym TIDE: (i) Transthoracic echocardiography under full Impella-unloading; (ii) Impella rate reduction in single 8–24 h-steps according to patients hemodynamics (blood pressure, heart rate, and ScVO₂), including a daily echocardiographic assessment at minimal flow (P2); (iii) Dobutamine stress-echocardiography; (iv) Right heart catheterization at rest and during Exercise-testing via handgrip. We here present clinical and hemodynamic data (including LV conductance data) from paradigmatic weaning protocols of awake patients admitted to our intensive care unit with cardiogenic shock. We discuss the clinical consequences of the TIDE algorithm, leading to either a bridge-to-recovery, or to a bridge-to-permanent LV assist device (LVAD) and/or transplantation. With this protocol we were able to wean 74.2% of the investigated patients successfully. 25.8% showed a permanent weaning failure and became LVAD candidates.

Conclusions: The proposed novel cardiovascular physiology-based weaning algorithm is based on the characterization of the extent and sustainment of LV unloading reached during hospitalization in patients with cardiogenic shock undergoing MVS with Impella in our center. Prospective studies are needed to validate the algorithm.