The PulseCath iVAC 2L left ventricular assist device: conversion to a percutaneous transfemoral approach

Case report of increased left ventricular end-diastolic pressure with pulsatile left ventricular assist device

Background

Left ventricular assist devices (LVADs) are increasingly utilized in cardiogenic shock and high-risk percutaneous coronary interventions (PCIs). These devices aspirate and expel blood from the left ventricle (LV) into the aorta, consequently reducing left ventricular end-diastolic pressure (LVEDP). We report a case of unexpected LVEDP rise under LV-to-aorta LVAD in the context of transcatheter aortic valve implantation (TAVI) and concomitant multi-vessel PCI.

Case summary

A patient with acute heart failure, severely depressed systolic LV function, severe aortic stenosis, and multi-vessel coronary artery disease underwent TAVI and concomitant PCI under pulsatile LVAD. Notably, the patient experienced unexpected shortness of breath and elevated LVEDP while under LVAD, which normalized immediately upon LVAD removal.

Discussion

Pulsatile LVAD enhances cardiac output by providing pulsatile support through a percutaneous bi-directional flow catheter. Despite expectations of reduced LVEDP and improved myocardial oxygen supply under LVAD support, we observed high LVEDP and clinical complaints of shortness of breath following TAVI and multi-vessel PCI. This case illustrates that an LVAD across the aortic valve may immobilize aortic leaflets and generate acute aortic regurgitation.

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.

Comparison of a pulsatile and a continuous flow left ventricular assist device in high-risk PCI

BACKGROUND

Mechanical circulatory support devices are able to generate additional cardiac output or maintain sufficient circulation during high-risk PCI. We prospectively compared the hemodynamic and clinical performance of the new iVAC2L® device with the Impella 2.5® device during high-risk PCI.

MATERIALS AND METHODS

In 40 patients [10 female, age 75 ± 8 years, left ventricular ejection fraction (LVEF) 44 ± 11%] high-risk PCIs were performed under iVAC (n = 20) or Impella (n = 20) support. Hemodynamic parameters were collected before and after device placement as well as immediately after PCI. Blood parameters of hemolysis were analyzed before and after support.

RESULTS

Correct device placement was achieved in 17 patients (85%) under iVAC use and in 19 patients (95%) under Impella use. PCI success was 98%. Under iVAC2L® support, systolic, diastolic and mean aortic blood pressure increased significantly with increasing support time. In contrast, aortic pressure increased directly under Impella support, but the increase was comparable between both devices. Impella support generated a significantly higher additional blood flow, as compared to iVAC support (2.07 ± 0.09 l/min vs. 1.25 ± 0.05 l/min, p < 0.001). Five patients (iVAC n = 3) suffered from critical events during high-risk PCI, but both devices were able to maintain stable hemodynamic conditions. After PCI, one severe bleeding occurred in each group. After Impella support, haptoglobin was significantly decreased, indicating potential hemolysis.

CONCLUSIONS

High-risk PCIs under support by both devices are feasible and safe and ensure stable hemodynamic conditions also if complications occur. Aortic pressure increases significantly with both devices, but later under iVAC use. Potential hemolysis occurs more frequent under Impella support.

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.

Concept and Design of a Novel Pulsatile Left Heart Assist Device-The PERKAT Left Ventricle System

Cardiogenic shock is associated with high mortality. Patients often require temporary mechanical circulatory support. We aimed to develop a percutaneously implantable, assist device that unloads the left ventricle (LV) in a pulsatile way. The PERkutane KATheter pump technologie (PERKAT LV) device consists of a nitinol pump chamber, which is covered by foils carrying outflow valves. A flexible tube with a pigtail-shaped tip and inflow holes represents the distal part of the pump. The system is designed for 16F percutaneous implantation. The nitinol chamber is placed in the descending aorta while the flexible tube bypasses aortic arch and ascending aorta with its tip in the LV. An intra-aortic balloon pump is placed into the chamber and connected to a console. Balloon deflation generates a blood flow from the LV into the pump chamber. During balloon inflation, blood leaves the system through the outflow foil valves in the descending aorta. Under different afterload settings using a 30 cc intra-aortic balloon pump and varying inflation/deflations rates, we recorded flow rates up to 3.0 L/min. Based on this, we believe that PERKAT LV is a promising approach for temporary LV support. The proposed design and its excellent performance give basis for in vivo tests in an animal model.

Interventional heart failure therapy: A new concept fighting against heart failure

Heart failure is a progressive disease that is associated with repeated exacerbations and hospitalizations. The rapid increase in the number of heart failure patients is a global health problem known as the 'heart failure pandemic'. To control the pandemic, multifaceted approaches are essential, ranging from prevention of onset to long-term disease management. Especially in patients with moderate to severe heart failure (stages C and D), surgical and catheter-based interventions are prerequisites for saving lives, preserving cardiac function, improving quality of life (QOL), and prognosis. In addition, various new medical technologies for these interventions have been clinically applied and have been shown to be effective against symptoms and improve the QOL and prognosis of patients with heart failure. Furthermore, the concept of interventional heart failure (IHF) therapy, which considers heart recovery and prevention of worsening of heart failure via multidisciplinary treatment using surgical, catheter interventions, and mechanical circulatory support devices, has been proposed worldwide. This review discusses the importance of IHF therapy in heart failure management, recent changes in interventional technologies and strategies for patients with heart failure, and worldwide education attempts for IHF specialists.

Future Devices for Percutaneous Mechanical Circulatory Support

Percutaneous mechanical circulatory support options include intra-aortic balloon pump, transvalvular axial flow pumps, left atrial to femoral artery pumping, and oxygenated right atrium to femoral artery circuits. Percutaneous mechanical circulatory support devices providing greater support have not proven superiority over the intra-aortic balloon pump. Novel counterpulsation devices target durability and ambulatory capability and direct unloading of left ventricle (LV) and right ventricle. Device innovations in transvalvular axial pumping include miniaturization of partial-support devices and development of larger self-expanding devices for near-complete LV support. Aortic entrainment pumping is a novel mode of blood displacement with potential benefits beyond reduced LV afterload.

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®

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is increasingly used in bi-ventricular failure with cardiogenic shock to maintain systemic perfusion. Nonetheless, it tends to increase left ventricular (LV) afterload and myocardial oxygen demand. In order to mitigate these negative effects on the myocardium, an Impella CP® (3.5 L/min Cardiac Output) can be used in conjunction with V-A ECMO (ECMELLA approach). We implemented this strategy in a patient with severe acute myocarditis complicated by cardiogenic shock. Due to a hemolysis crisis, Impella CP® had to be substituted with PulseCath iVAC2L®, which applies pulsatile flow to unload the LV. A subsequent improvement in LV systolic function was noted, with increased LV ejection fraction (LVEF), LV end-diastolic diameter (LVEDD) reduction, and a reduction in plasma free hemoglobin. This case documents the efficacy of iVAC2L in replacing Impella CP as a LV vent during V-A ECMO, with less hemolysis.

PulseCath iVAC2L: next-generation pulsatile mechanical circulatory support

Contemporary state of the art percutaneous coronary intervention techniques offer treatment strategies and solutions to an increasing number of patients with heart failure and complex coronary artery disease. Percutaneous mechanical circulatory support is intended to alleviate the mechanical and energetic workload imposed to a failing ventricle by reducing left ventricle pressures and volumes and potentially also increasing coronary blood flow. The PulseCath iVAC2L is a transaortic left ventricular assist device that applies a pneumatic driving system to produce pulsatile forward flow. Herein, the essential aspects regarding iVAC2L are discussed with focus on its mechanisms of action and the available clinical experience.

High-risk PCI under support of a pulsatile left ventricular assist device - First German experience with the iVAC2L system

BACKGROUND

During high-risk percutaneous coronary intervention (PCI) complications may occur, leading to unstable hemodynamic conditions. Circulatory support devices might help to intercept these conditions by supporting cardiac output. We investigated in a prospective trial the performance of the pulsatile iVAC2L system in the setting of high-risk PCI.

METHODS

Circulatory support by the iVAC2L device was attempted in 20 consecutive patients (three females, mean age 72 ± 9 years, LVEF 44 ± 12%) undergoing high-risk PCI. Aortic pressure data were collected after device placement and immediately after PCI.

RESULTS

Successful device placement was achieved in 17 (85%) patients; kinking of iliac artery and device length limited correct device placement in the remaining three patients. PCI success was 100%. With ongoing support (overall support time 122 ± 32min) systolic, diastolic and mean blood pressure increased significantly and kept the higher level until device removal. Critical events occurred in three patients (massive vasospasm, coronary perforation, no-flow in LCA after wire placement), but the iVAC2L device helped to maintain stable hemodynamic conditions with no need for cardiopulmonary resuscitation. Serial controls of hemolysis related parameters in a subgroup of ten patients revealed no significant device related hemolysis after the performance of the iVAC2l system.

CONCLUSIONS

High-risk PCI under hemodynamic support by the iVAC2L device is feasible and safe. Aortic pressure increases with ongoing support. The device helps to stabilize hemodynamic situations if complications occur.

New-generation mechanical circulatory support during high-risk PCI: a cross-sectional analysis

AIMS

The aim of the study was to establish the value of new-generation mechanical circulatory support (MCS) devices such as HeartMate PHP, Impella CP and PulseCath iVAC2.

METHODS AND RESULTS

We retrospectively analysed all consecutive elective high-risk PCI procedures performed in the Erasmus Medical Center (2011-2018) in order to compare MCS protected and unprotected patients. The primary endpoint was a composite of procedure-related adverse events including death (<24 hours), cardiac arrest, need for vasopressors, rescue MCS, endotracheal intubation and limb ischaemia with need for surgery. Secondary endpoints included 30-day survival. A total of 198 elective high-risk PCI patients were included (69 [35%] MCS protected, 129 [65%] MCS unprotected). When compared with unprotected patients, MCS protected patients had a significantly worse left ventricular ejection fraction (LVEF) (25±10 vs 33±8%, p<0.01) and higher SYNTAX I score (33±11 vs 24±8, p<0.01). The primary endpoint occurred in 26 (20%) of the unprotected patients and in 6 (9%) of the MCS protected patients (OR 0.38, 95% CI: 0.15-0.97, p=0.04). Patients under 75 years of age, with a SYNTAX I score above 32 and with an LVEF below 30% showed most potential benefit from MCS. Survival during the first 24 hours after the procedure and at 30 days was significantly higher in MCS protected patients (100% vs 95%, p=0.04 at 24 hours, and 98% vs 87%, OR 10.32, 95% CI: 1.34-79.31, p=0.006 at 30 days).

CONCLUSIONS

In a consecutive real-world cohort of high-risk PCI patients, protection with new-generation MCS resulted in better procedural outcomes despite worse EF and more complex coronary artery disease at baseline. Larger prospective studies are needed to confirm these findings.

Design and principle of operation of the HeartMate PHP (percutaneous heart pump)

The HeartMate PHP (percutaneous heart pump) is a second-generation transcatheter axial flow circulatory support system. The collapsible catheter pump is inserted through a 14 Fr sheath, deployed across the aortic valve expanding to 24 Fr and able to deliver up to 5 L/min blood flow at minimum haemolytic risk. As such, this device may be a valuable adjunct to percutaneous coronary intervention (PCI) of challenging lesions in high-risk patients or treatment of cardiogenic shock. This technical report discusses: (i) the HeartMate PHP concept, (ii) the implantation technique, (iii) the haemodynamic performance in an in vitro cardiovascular flow testing set-up, and (iv) preliminary clinical experience. An update on the device, produced by St. Jude Medical/Abbott Laboratories, can be found in the Appendix.

First successful prevention of cardiopulmonary resuscitation during high-risk percutaneous coronary intervention by use of a pulsatile left ventricular assist device: baptism of fire of the iVAC2L device: a case report

Introduction

Efforts in percutaneous coronary intervention (PCI) lead to interventional treatment of complex stenoses as an alternative to coronary bypass surgery. Nevertheless, complications during PCI can occur with sudden need for circulatory support. Circulatory support devices are helpful tools during high-risk PCI to generate additional output or maintain sufficient circulation in critical situations.

Case description

We report the case of the first successful prevention of cardiopulmonary resuscitation by use of transfemoral pulsatile ventricular assist device with up to 2l additional cardiac output during a high-risk PCI in an 80-year old man with complex stenosis and a history of ventricular fibrillation during prior coronary angiography.

Discussion

The device managed to maintain an adequate circulation during massive vasospasm and bradycardia. The iVAC2L seems to be a useful tool in high-risk PCI. Its general effect on haemodynamics and patients' outcome has to be evaluated in larger multi-centre studies.

Percutaneous ventricular assist devices and extracorporeal life support: current applications

Percutaneous mechanical circulatory support devices, such as intra-aortic balloon pump (IABP), active left ventricular assist devices (LVAD) or extracorporeal life support (ECLS), are treatment options for selected patients in cardiogenic shock, undergoing cardiopulmonary resuscitation, or high-risk percutaneous coronary intervention and coronary artery bypass grafting. Potential benefits include the maintenance of organ function and the reduction of intracardiac pressures, volumes, and oxygen consumption. On the other hand, they are invasive, resource intensive, and can be associated with serious complications. Thus, their potential benefits must be weighed against the inherent risks. Despite the lack of sufficient scientific evidence, the use of mechanical circulatory support devices has risen considerably in recent years. This educational article covers practical issues of IABP, LVAD, and ECLS with respect to patient and device selection, implantation technique, potential complications, and future perspectives.

First high-risk percutaneous coronary intervention under use of the iVAC2l system in Germany

Percutaneous coronary intervention of complex stenoses is becoming more and more of an alternative to coronary bypass surgery. Nevertheless, complications can occur and lead to the need for circulatory support and/or emergency surgery. Circulatory support devices like the intra-aortic balloon pump showed only low benefit in patients' outcome. Devices with higher cardiac output necessitate more complex implantation procedures. We report the case of the first successful use of a transfemoral pulsatile ventricular assist device with up to 2 l additional cardiac output during high-risk percutaneous coronary intervention in a 74-year-old man with complex stenosis. The device was safe and feasible during coronary intervention in its use. Its beneficial effect on hemodynamics and patients' outcome has to be evaluated in larger multicenter studies.

Current and novel approaches to treat patients presenting with ST elevation myocardial infarction

INTRODUCTION

Primary percutaneous coronary intervention (PCI) represents the gold-standard treatment for patients presenting with an ST-elevation myocardial infarction (STEMI). Acute myocardial infarction is a complex clinical scenario, and an appropriate therapeutic approach could be represented by a balanced integration between healthcare system and medical competence.

AREAS COVERED

In this review we discuss how a primary PCI network, and the new therapeutic options could be coupled in order to obtain improved clinical outcomes. The present report will focus on three main issues related to STEMI patients, namely, out of hospital management, primary PCI and pharmacological treatment. Expert commentary: A possible correct approach to a patient presenting a STEMI could be considered as a stepwise process, given by 5 steps: reducing the time to reperfusion; dual antiplatelet administration; radial access; new generation drug eluting stent implantation; long term management.