Mechanical Assist Device-Assisted Percutaneous Coronary Intervention: The Use of Impella Versus Extracorporeal Membrane Oxygenation as an Emerging Frontier in Revascularization in Cardiogenic Shock

Abstract

The extracorporeal membrane oxygenation (ECMO) procedure aids in the provision of prolonged cardiopulmonary support, whereas the Impella device (Abiomed, Danvers, MA) is a ventricular assist device that maintains circulation by pumping blood into the aorta from the left ventricle. Blood is circulated in parallel with the heart by Impella. It draws blood straight into the aorta from the left ventricle, hence preserving the physiological flow. ECMO bypasses the left atrium and the left ventricle, and the end consequence is a non-physiological flow. In this article, we conducted a detailed analysis of various publications in the literature and examined various modalities pertaining to the use of ECMO and Impella for cardiogenic shocks, such as efficacy, clinical outcomes, cost-effectiveness, device-related complications, and limitations. The Impella completely unloads the left ventricle, thereby significantly reducing the effort of the heart. Comparatively, ECMO only stabilizes a patient with cardiogenic shock for a short stretch of time and does not lessen the efforts of the left ventricle ("unload" it). In the acute setting, both devices reduced left ventricular end-diastolic pressure and provided adequate hemodynamic support. By comparing patients on Impella to those receiving ECMO, it was found that patients on Impella were associated with better clinical results, quicker recovery, limited complications, and reduced healthcare costs; however, there is a lack of conclusive studies performed demonstrating the reduction in long-term mortality rates. Considering the effectiveness of given modalities and taking into account the various studies described in the literature, Impella has reported better clinical outcomes although more clinical trials are needed for establishing the effectiveness of these interventional approaches in revascularization in cardiogenic shock.

Extracorporeal Membrane Oxygenation (VA-ECMO) in Management of Cardiogenic Shock

“…It is known that VA-ECMO reduces central venous pressure while increasing MAP and the arteriovenous pressure gradient, thereby increasing systemic perfusion [2]. One theory suggests that VA-ECMO reduces right ventricular (RV) preload, RV blood flow into the pulmonary artery, and peripheral venous congestion, which results in a decrease in LV end diastolic volume and pressure and promotes hemodynamic stabilization [2,6,11,52]. However, another proposes that VA-ECMO increases cardiac afterload, which subsequently results in a rise in LVEDP, left atrial pressure, and pulmonary capillary wedge pressure, contributing to worsening of LV function and pulmonary edema [4,6,14,53].…”

“…One theory suggests that VA-ECMO reduces right ventricular (RV) preload, RV blood flow into the pulmonary artery, and peripheral venous congestion, which results in a decrease in LV end diastolic volume and pressure and promotes hemodynamic stabilization [2,6,11,52]. However, another proposes that VA-ECMO increases cardiac afterload, which subsequently results in a rise in LVEDP, left atrial pressure, and pulmonary capillary wedge pressure, contributing to worsening of LV function and pulmonary edema [4,6,14,53]. It has been estimated that up to 30% of patients placed on VA-ECMO will exhibit pulmonary edema [17,[53][54][55].…”

“…The major disadvantage with peripheral VA-ECMO is that it lacks complete LV "unloading" capabilities-it does not lessen the work of the LV-therefore, optimization of preload, afterload, and contractility may be needed to maintain forward flow through the LV and prevent pulmonary edema and decreased LV function [6,17,18]. When medical therapy with diuretics and inotropes are insufficient, mechanical means, or LV "venting" strategies, are often used [3,18].…”

“…CS can occur in the setting of an acute cardiac event or due to decompensation of underlying chronic cardiomyopathy [4]. The leading cause, accounting for approximately 80% of cases, is acute myocardial infarction (AMI), and patients presenting with ST-segment elevation myocardial infarction are at greatest risk [5,6]. Other common causes include chronic heart failure, fulminant myocarditis, valvular heart disease, high-risk pulmonary embolism, and hemodynamically unstable arrhythmias, and the incidence of these etiologies is increasing [2,7].…”

Acute coronary syndrome associated cardiogenic shock in the catheterization laboratory: peripheral veno-arterial extracorporeal membrane oxygenator management and recommendations

“…Among these devices, the microaxial transvalvular device (Impella) is increasingly deployed in cases of CS ACS, either alongside or concurrently with VA-ECMO. Impella operates as a catheter-based, continuous axial flow pump, allowing for active propulsion of blood into the aorta, while reducing myocardial stress and enhancing systemic circulation (9,17). The safety and efficacy of Impella and VA-ECMO in treating critically ill patients with CS ACS remains a topic of debate due to conflicting evidence.…”