Percutaneous left ventricular assist in ischemic cardiac arrest

Balanced Biventricular Assist Versus Extracorporeal Membrane Oxygenation in Cardiac Arrest

Mechanical assist devices in refractory cardiac arrest are increasingly employed. We compared the hemodynamics and organ perfusion during cardiac arrest with either veno-arterial extracorporeal membrane oxygenation (ECMO) or biventricular assisted circulation combining left- and right-sided impeller devices (BiPella) in an acute experimental setting. Twenty pigs were randomized in two equal groups receiving circulatory support either by ECMO or by BiPella during 40 minutes of ventricular fibrillation (VF) followed by three attempts of cardioversion, and if successful, 60 minute observation with spontaneous, unsupported circulation. Hemodynamic variables were continuously recorded. Tissue perfusion was evaluated by fluorescent microsphere injections. Cardiac function was visualized by intracardiac echocardiography. During VF device output, carotid flow, kidney perfusion, mean aortic pressure (AOPmean), and mean left ventricular pressure (LVPmean) were all significantly higher in the ECMO group, and serum-lactate values were lower compared with the BiPella group. No difference in myocardial or cerebral perfusion was observed between groups. In 15 animals with sustained cardiac function for 60 minutes after return of spontaneous circulation, left ventricular subendocardial blood flow rate averaged 0.59 ± 0.05 ml/min/gm during VF compared with 0.31 ± 0.07 ml/min/gm in five animals with circulatory collapse (p = 0.005). Corresponding values for the midmyocardium was 0.91 ± 0.06 vs. 0.65 ± 0.15 ml/min/gm (p = 0.085). Both BiPella and ECMO could sustain vital organ function. ECMO provided a more optimal systemic circulatory support related to near physiologic output. Myocardial tissue perfusion and sustained cardiac function were related to coronary perfusion pressure during VF, irrespective of mode of circulatory support.

Cardiac Arrest in the Cardiac Catheterization Laboratory: Combining Mechanical Chest Compressions and Percutaneous LV Assistance

OBJECTIVES

The aim of this study was to evaluate the optimal treatment approach for cardiac arrest (CA) occurring in the cardiac catheterization laboratory.

BACKGROUND

CA can occur in the cath lab during high-risk percutaneous coronary intervention. While attempting to correct the precipitating cause of CA, several options are available to maintain vital organ perfusion. These include manual chest compressions, mechanical chest compressions, or a percutaneous left ventricular assist device.

METHODS

Eighty swine (58 ± 10 kg) were studied. The left main or proximal left anterior descending artery was occluded. Ventricular fibrillation (VFCA) was induced and circulatory support was provided with 1 of 4 techniques: either manual chest compressions (frequently interrupted), mechanical chest compressions with a piston device (LUCAS-2), an Impella 2.5 L percutaneously placed LVAD, or the combination of mechanical chest compressions and the percutaneous left ventricular assist device. The study protocol included 12 min of left main coronary occlusion, reperfusion, with defibrillation attempted after 15 min of VFCA. Primary outcome was favorable neurological function (CPC 1 or 2) at 24 h, while secondary outcomes included return of spontaneous circulation and hemodynamics.

RESULTS

Manual chest compressions provided fewer neurologically intact surviving animals than the combination of a mechanical chest compressor and a percutaneous LVAD device (0% vs. 56%; p < 0.01), while no difference was found between the 2 mechanical approaches (28% vs. 35%: p = 0.75). Comparing integrated coronary perfusion pressure showed sequential improvement in hemodynamic support with mechanical devices (401 ± 230 vs. 1,337 ± 905 mm Hg/s; p = 0.06).

CONCLUSIONS

Combining 2 mechanical devices provided superior 24-h survival with favorable neurological recovery compared with manual compressions during moderate duration VFCA associated with an acute coronary occlusion in the animal catheterization laboratory.

Impella use in acute myocardial infarction complicated by cardiogenic shock and cardiac arrest: Analysis of 10 years registry data

AIMS

To assess characteristics and outcome of patients treated with Impella for acute myocardial infarction (AMI) complicated by severe cardiogenic shock (CS) or cardiac arrest (CA).

METHODS AND RESULTS

From 2008 through 2017, 92 patients with AMI complicated by CS were treated with Impella. Survival varied according to clinical presentation. Patients in cardiogenic shock without CA had a 75% 30-day survival. Patients with CA and return of spontaneous circulation (ROSC) had a 43% survival and those with CA and ongoing cardio-pulmonary resuscitation (CPR) had a 6% 30-day survival. Age, pre-existing hypertension, coronary disease, ventilatory support and use of adrenergic agents were associated with worse prognosis. Complications were predominantly access site related.

CONCLUSIONS

In this registry of patients with AMICS treated with Impella, hypertension and older age were found to be negatively predictive for survival. Patients without CA had the highest 30-day survival. In patients with ROSC, survival was strongly related to age and comorbidity. Patients with ongoing CPR had very high mortality.

The Evolving Role of the Cardiac Catheterization Laboratory in the Management of Patients With Out-of-Hospital Cardiac Arrest: A Scientific Statement From the American Heart Association

Coronary artery disease is prevalent in different causes of out-of-hospital cardiac arrest (OHCA), especially in individuals presenting with shockable rhythms of ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT). The purpose of this report is to review the known prevalence and potential importance of coronary artery disease in patients with OHCA and to describe the emerging paradigm of treatment with advanced perfusion/reperfusion techniques and their potential benefits on the basis of available evidence. Although randomized clinical trials are planned or ongoing, current scientific evidence rests principally on observational case series with their potential confounding selection bias. Among patients resuscitated from VF/pVT OHCA with ST-segment elevation on their postresuscitation ECG, the prevalence of coronary artery disease has been shown to be 70% to 85%. More than 90% of these patients have had successful percutaneous coronary intervention. Conversely, among patients resuscitated from VF/pVT OHCA without ST-segment elevation on their postresuscitation ECG, the prevalence of coronary artery disease has been shown to be 25% to 50%. For these patients, early access to the cardiac catheterization laboratory is associated with a 10% to 15% absolute higher functionally favorable survival rate compared with more conservative approaches of late or no access to the cardiac catheterization laboratory. In patients with VF/pVT OHCA refractory to standard treatment, a new treatment paradigm is also emerging that uses venoarterial extracorporeal membrane oxygenation to facilitate return of normal perfusion and to support further resuscitation efforts, including coronary angiography and percutaneous coronary intervention. The burden of coronary artery disease is high in this patient population, presumably causative in most patients. The strategy of venoarterial extracorporeal membrane oxygenation, coronary angiography, and percutaneous coronary intervention has resulted in functionally favorable survival rates ranging from 9% to 45% in observational studies in this patient population. Patients with VF/pVT should be considered at the highest severity in the continuum of acute coronary syndromes. These patients have a significant burden of coronary artery disease and acute coronary thrombotic events. Evidence from randomized trials will further define optimal clinical practice.

Design and Development of a Miniaturized Percutaneously Deployable Wireless Left Ventricular Assist Device: Early Prototypes and Feasibility Testing

The current left ventricular assist devices (LVADs) are limited by a highly invasive implantation procedure in a severely unstable group of advanced heart failure patients. Additionally, the current transcutaneous power drive line acts as a nidus for infection resulting in significant morbidity and mortality. In an effort to decrease this invasiveness and eliminate drive line complications, we have conceived a wireless miniaturized percutaneous LVAD, capable of being delivered endovascularly with a tether-free operation. The system obviates the need for a transcutaneous fluid purge line required in existing temporary devices by utilizing an incorporated magnetically coupled impeller for a complete seal. The objective of this article was to demonstrate early development and proof-of-concept feasibility testing to serve as the groundwork for future formalized device development. Five early prototypes were designed and constructed to iteratively minimize the pump size and improve fluid dynamic performance. Various magnetic coupling configurations were tested. Using SolidWorks and ANSYS software for modeling and simulation, several geometric parameters were varied. HQ curves were constructed from preliminary in vitro testing to characterize the pump performance. Bench top tests showed no-slip magnetic coupling of the impeller to the driveshaft up to the current limit of the motor. The pump power requirements were tested in vitro and were within the appropriate range for powering via a wireless energy transfer system. Our results demonstrate the proof-of-concept feasibility of a novel endovascular cardiac assist device with the potential to eventually offer patients an untethered, minimally invasive support.

Cardiac Arrest in the Catheterization Laboratory

BACKGROUND

Cardiac arrest in the Catheterization Lab is a rare and unique scenario that is often logistically challenging. It often has dire prognosis especially in patients suffering from severe pre-existing illnesses (high risk patient) such as acute myocardial infarction with cardiogenic shock, or patients undergoing high risk procedures. As the number of complex interventional procedures increases, cardiac arrest in the cath lab will become more common and optimal management of this scenario is critical for both the patient and operator.

CONCLUSION

In this review, we will discuss the special challenges during the resuscitation efforts in cath lab, especially with tradition chest compression. We will discuss the alternative options including mechanical compression devices and Invasive Percutaneous Mechanical Circulatory Support Devices. Finally, we will offer management suggestions on selecting the appropriate circulatory support device based on clinical and anatomic risks.

Doubling survival and improving clinical outcomes using a left ventricular assist device instead of chest compressions for resuscitation after prolonged cardiac arrest: a large animal study

Introduction

Despite improvements in pre-hospital and post-arrest critical care, sudden cardiac arrest (CA) remains one of the leading causes of death. Improving circulation during cardiopulmonary resuscitation (CPR) may improve survival rates and long-term clinical outcomes after CA.

Methods

In a porcine model, we compared standard CPR (sCPR; n =10) with CPR using an intravascular cardiac assist device without additional chest compressions (iCPR; n =10) following 10 minutes of electrically induced ventricular fibrillation (VF). In a separate crossover experiment, 10 additional pigs were subjected to 10 minutes of VF and 6 minutes of sCPR; the iCPR device was then implanted if a return of spontaneous circulation (ROSC) was not achieved using sCPR. Animals were evaluated in respect to intra- and post-arrest hemodynamics, survival, functional outcome and cerebral and myocardial lesions following CPR. We hypothesized that iCPR would result in more frequent ROSC and better functional recovery than sCPR.

Results

iCPR produced a mean flow of 1.36 ± 0.02 L/min, leading to significantly higher coronary perfusion pressure (CPP) values during the early period of CPR (22 ± 10 mmHg vs. 9 ± 5 mmHg, P ≤0.01, 1 minute after start of CPR; 20 ± 11 mmHg vs. 10 ± 7 mmHg, P =0.03, 2 minutes after start of CPR), resulting in high ROSC rates (100% in iCPR vs. 50% in sCPR animals; P =0.03). iCPR animals showed significantly lower serum S100 levels at 10 and 30 minutes following ROSC (3.5 ± 0.6 ng/ml vs. 7.4 ± 3.0 ng/ml 30 minutes after ROSC; P ≤0.01), as well as superior clinical outcomes based on overall performance categories (2.9 ± 1.0 vs. 4.6 ± 0.8 on day 1; P ≤0.01). In crossover experiments, 80% of animals required treatment with iCPR after failed sCPR. Notably, ROSC was still achieved in six of the remaining eight animals (75%) after a total of 22.8 ± 5.1 minutes of ischemia.

Conclusions

In a model of prolonged cardiac arrest, the use of iCPR instead of sCPR improved CPP and doubled ROSC rates, translating into improved clinical outcomes.

Percutaneous left ventricular assist devices during cardiogenic shock and high-risk percutaneous coronary interventions

Left ventricular assist devices were developed to support the function of a failing left ventricle. Owing to recent technological improvements, ventricular assist devices can be placed by percutaneous implantation techniques, which offer the advantage of fast implantation in the setting of acute left ventricular failure. This article reviews the growing evidence supporting the clinical use of left ventricular assist devices. Specifically, we discuss the use of left ventricular assist devices in patients with cardiogenic shock, in patients with acute ST-elevation myocardial infarction without shock, and during high-risk percutaneous coronary interventions.

Randomised comparison of percutaneous left ventricular assist device with open-chest cardiac massage and with surgical assist device during ischaemic cardiac arrest

AIMS

A percutaneous left ventricular assist device can maintain blood flow to vital organs during ventricular fibrillation and may improve outcomes in ischaemic cardiac arrest. We compared haemodynamic and clinical effects of a percutaneous left ventricular assist device with a larger device deployed via endovascular prosthesis and with open-chest cardiac massage during ischaemic cardiac arrest.

METHODS

Eighteen swine were randomised into three groups. After thoracotomy, coronary ischaemia and ventricular fibrillation was induced. Cardiac output was measured with transit-time flowmetry. Tissue perfusion was measured with microspheres. Defibrillation was performed after 20 min.

RESULTS

Cardiac output with cardiac massage was 1129 mL min⁻¹ vs. 1169 mL min⁻¹ with the percutaneous- and 570 mL min⁻¹ with the surgical device (P < 0.05 surgical vs. others). End-tidal CO₂ was 3.3 kPa with cardiac massage vs. 3.2 kPa with the percutaneous- and 2.3 kPa with the surgical device (P < 0.05 surgical vs. others). Subepicardial perfusion was 0.33 mL min⁻¹ g⁻¹ with cardiac massage vs. 0.62 mL min⁻¹ g⁻¹ with both devices (P < 0.05 devices vs. massage), cerebral perfusion was comparable between groups (all reported values after 3 min cardiac arrest, all P<0.05 vs. baseline, all P = NS for 3 min vs. 15 min). Return of spontaneous circulation was achieved in 5/6 subjects with cardiac massage vs. 6/6 with the percutaneous- and 4/6 with the surgical device (P = NS).

CONCLUSION

The percutaneous device improved myocardial perfusion, maintained cerebral perfusion and systemic circulation with similar rates of successful defibrillation vs. cardiac massage. Increased delivery was not obtained with the surgical device during cardiac arrest.

Treatment of cardiogenic shock with left ventricular assist device combined with cardiac resynchronization therapy: a case report

Cardiogenic shock has a poor prognosis with established treatment strategies. We report a 62 years old man with heart failure exacerbating into refractory cardiogenic shock successfully treated with the combination of a percutaneous left ventricular assist device (LVAD) and subacute cardiac resynchronization therapy (CRT) implantable cardioverter-defibrillator device (CRT-D).