Preventive Impella® Support in High-Risk Patients Undergoing Cardiac Surgery

Impella - Current issues and future expectations for the percutaneous, microaxial flow left ventricular assist device

The importance of temporary mechanical circulatory support for treating acute heart failure with cardiogenic shock is increasingly recognized, and Impella (Abiomed, Danvers, MA, USA) has received particular attention in this regard. Impella is an axial flow left ventricular assist device (LVAD) built into the tip of a catheter. It is inserted via a peripheral artery and implanted into the left ventricle. Although the morphology of Impella is different from a typical LVAD, it has similar actions and effects as an LVAD in terms of left ventricular drainage and aortic blood delivery. Impella increases mean arterial pressure (MAP) and systemic blood flow, thereby improving peripheral organ perfusion and promoting recovery from multiple organ failure. In addition, left ventricular unloading with increased MAP increases coronary perfusion and decreases myocardial oxygen demand, thereby promoting myocardial recovery. Impella is also useful as a mechanical vent of the left ventricle in patients supported with veno-arterial extracorporeal membrane oxygenation. Indications for Impella include emergency use for cardiogenic shock and non-emergent use during high-risk percutaneous coronary intervention and ventricular tachycardia ablation. Its intended uses for cardiogenic shock include bridge to recovery, durable device, heart transplantation, and heart surgery. Prophylactic use of Impella in high-risk patients undergoing open heart surgery to prevent postcardiotomy cardiogenic shock is also gaining attention. While there have been many case reports and retrospective studies on the benefits of Impella, there is little evidence based on sufficiently large randomized controlled trials (RCTs). Currently, several RCTs are now ongoing, which are critical to determine when, for whom, and how these devices should be used. In this review, we summarize the principles, physiology, indications, and complications of the Impella support and discuss current issues and future expectations for the device.

Low Left-Ventricular Ejection Fraction as a Predictor of Intraprocedural Cardiopulmonary Resuscitation in Patients Undergoing Transcatheter Aortic Valve Implantation

Transcatheter aortic valve replacement (TAVR) has become an established alternative to surgical aortic valve replacement (AVR) for patients with moderate-to-high perioperative risk. Periprocedural TAVR complications decrease with growing expertise of implanters. Nevertheless, TAVR can still be accompanied by life-threatening adverse events such as intraprocedural cardiopulmonary resuscitation (CPR). This study analyzed the role of a reduced left-ventricular ejection fraction (LVEF) in intraprocedural complications during TAVR. Perioperative and postoperative outcomes from patients undergoing TAVR in a high-volume center (600 cases per year) were analyzed retrospectively with regard to their left-ventricular ejection fraction. Patients with a reduced left-ventricular ejection fraction (EF ≤ 40%) faced a significantly higher risk of perioperative adverse events. Within this cohort, patients were significantly more often in need of mechanical ventilation (35% vs. 19%). These patients also underwent CPR (17% vs. 5.8%), defibrillation due to ventricular fibrillation (13% vs. 5.4%), and heart-lung circulatory support (6.1% vs. 2.5%) more often. However, these intraprocedural adverse events showed no significant impact on postoperative outcomes regarding in-hospital mortality, stroke, or in-hospital stay. A reduced preprocedural LVEF is a risk factor for intraprocedural adverse events. With respect to this finding, the identified patient cohort should be treated with more caution to prevent intraprocedural incidents.

Temporary mechanical circulatory support & enhancing recovery after cardiac surgery

PURPOSE OF REVIEW

This review highlights the integration of enhanced recovery principles with temporary mechanical circulatory support associated with adult cardiac surgery.

RECENT FINDINGS

Enhanced recovery elements and efforts have been associated with improvements in quality and value. Temporary mechanical circulatory support technologies have been successfully employed, improved, and the value of their proactive use to maintain hemodynamic goals and preserve long-term myocardial function is accruing.

SUMMARY

Temporary mechanical circulatory support devices promise to enhance recovery by mitigating the risk of complications, such as postcardiotomy cardiogenic shock, organ dysfunction, and death, associated with adult cardiac surgery.

Temporary mechanical circulatory support with Impella in cardiac surgery: A systematic review

INTRODUCTION

Perioperative cardiogenic shock (CS) in cardiac surgery is still burdened by a high mortality risk. The introduction of Impella pumps in the therapeutic armory of temporary mechanical circulatory support (tMCS) has potential implications to improve the management of complex cases, although it has never been systematically addressed. We performed a systematic review of the reported use of tMCS with Impella in cardiac surgery.

METHODS

We searched PubMed for all original studies on the Impella use in adult patients in cardiac surgery.

RESULTS

Nineteen studies (out of 151 identified by search string) were included. All studies were observational and all but one (95%) were retrospective. Seven studies focused on the implantation of Impella in the pre-operative setting (coronary or valvular surgery), either as a prophylactic device in high-risk cases (3 studies) or in patients with CS as stabilization tool prior to cardiac surgery procedure (4 studies). Three studies reported the use of Impella as periprocedural support for percutaneous valvular procedure, three as bridge to heart replacement, and six for postcardiotomy CS. Impella support had a low complication rate and was successful in supporting hemodynamics pre-, intra- and postoperatively. Most consistently reported data were left-ventricular ejection fraction at implant, short-term survival and weaning rate.

CONCLUSIONS

tMCS with Impella in cardiac surgery patients is feasible and successful. It can be applied in selected cardiac surgery patients and presents advantages over other types of support. Systematic prospective studies are needed to standardize indications for implant and management of surgical issues, and to identify which patients may benefit.

Programmatic approach to patients with advanced ischemic cardiomyopathy: Integrating microaxial support into strategies for the modern era

Patients with advanced ischemic cardiomyopathy manifesting as left ventricular dysfunction exist along a spectrum of severity and risk, and thus decision-making surrounding optimal management is challenging. Treatment pathways can include medical therapy as well as revascularization through percutaneous coronary intervention or coronary artery bypass grafting. Additionally, temporary and durable mechanical circulatory support, as well as heart transplantation, may be optimal for select patients. Given this spectrum of risk and the complexity of treatment pathways, patients may not receive appropriate therapy given their perceived risk, which can lead to sub-satisfactory outcomes. In this review, we discuss the identification of high-risk ischemic cardiomyopathy patients, along with our programmatic approach to patient evaluation and perioperative optimization. We also discuss our strategies for therapeutic decision-making designed to optimize both short- and long-term patient outcomes.

Association of timing of percutaneous left ventricular assist device insertion with outcomes in patients undergoing cardiac surgery

Objectives

The aim of this study was to explore the associations between percutaneous ventricular assist device (pVAD) insertion timing relative to cardiac surgery and patient outcomes.

Methods

The Nationwide Inpatient Sample was queried for patients undergoing cardiac surgery and pVAD insertion in the same admission from 2016 to 2019. Patients were stratified by timing of pVAD insertion. Preoperative characteristics, postoperative complications, and mortality were compared among groups.

Results

Overall, 3695 patients underwent cardiac surgery and pVAD insertion during the same hospitalization (pre: 1130, intra: 1690, and post: 875). The distribution of cardiac surgery procedures was similar across groups. Median Elixhauser Comorbidity Index was 13 for pre-, 15 for intra-, and 17 for postoperative pVAD patients (P = .021). Patients who received a postoperative pVAD were associated with increased mortality (pre: 18%, intra: 39%, and post: 54%; P < .01). Increased complication rates were also associated with postoperative pVAD insertion (pre: 61%, intra: 55%, and post: 75%; P < .01). Preoperative pVAD insertion was associated with increase rates of sepsis (pre: 18%, intra: 9.8%, and post: 17%; P = .01) and pneumonia (pre: 38%, intra: 23%, and post: 31%; P < .01). Postoperative pVAD insertion was associated with increased rates of gastrointestinal bleeding (pre: 2.2%, intra: 3.0%, and post: 7.4%; P = .01), renal failure (pre: 10%, intra: 9.2%, and post: 17%; P = .01), and prolonged ventilation (pre: 44%, intra: 41%, and post: 54%; P = .02).

Conclusions

Postoperative pVAD insertion following cardiac surgery was associated with increased complications and mortality compared with preoperative or intraoperative insertion. Further studies should explore optimal utilization and timing of pVAD insertion in patients undergoing cardiac surgery.

Coronary artery bypass grafting in left ventricular dysfunction: when and how

PURPOSE OF REVIEW

The surgical management of patients undergoing coronary artery bypass grafting (CABG) with low ejection fraction presents unique challenges that require meticulous attention to details and good surgical technique and judgement. This review details the latest evidence and best practices in the care of such patients.

RECENT FINDINGS

CABG in patients with low ejection fraction carries a significant risk of perioperative mortality and morbidity related to the development of postcardiotomy shock. Preoperative optimization with pharmacological or mechanical support is required, especially in patients with cardiogenic shock. Rapid and complete revascularization is what CABG surgeons aim to achieve. Multiple arterial revascularization should be reserved to selected patients. Off-pump CABG, on-pump breathing heart CABG, and new cardioplegic solutions remain of uncertain benefit compared with traditional CABG.

SUMMARY

Tremendous advancements in CABG allowed surgeons to offer revascularization to patients with severe left ventricular dysfunction and multivessel disease with acceptable risk. Despite that, there is a lack of comprehensive and robust studies particularly on long-term outcomes. Individualized patient assessment and a heart team approach should be used to determine the optimal surgical strategy for each patient.

Short-term mechanical support with the Impella 5.x for mitral valve surgery in advanced heart failure-protected cardiac surgery

Introduction

Surgical treatment of patients with mitral valve regurgitation and advanced heart failure remains challenging. In order to avoid peri-operative low cardiac output, Impella 5.0 or 5.5 (5.x), implanted electively in a one-stage procedure, may serve as a peri-operative short-term mechanical circulatory support system (st-MCS) in patients undergoing mitral valve surgery.

Methods

Between July 2017 and April 2022, 11 consecutive patients underwent high-risk mitral valve surgery for mitral regurgitation supported with an Impella 5.x system (Abiomed, Inc. Danvers, MA). All patients were discussed in the heart team and were either not eligible for transcatheter edge-to-edge repair (TEER) or surgery was considered favorable. In all cases, the indication for Impella 5.x implantation was made during the preoperative planning phase.

Results

The mean age at the time of surgery was 61.6 ± 7.7 years. All patients presented with mitral regurgitation due to either ischemic (n = 5) or dilatative (n = 6) cardiomyopathy with a mean ejection fraction of 21 ± 4% (EuroScore II 6.1 ± 2.5). Uneventful mitral valve repair (n = 8) or replacement (n = 3) was performed via median sternotomy (n = 8) or right lateral mini thoracotomy (n = 3). In six patients, concomitant procedures, either tricuspid valve repair, aortic valve replacement or CABG were necessary. The mean duration on Impella support was 8 ± 5 days. All, but one patient, were successfully weaned from st-MCS, with no Impella-related complications. 30-day survival was 90.9%.

Conclusion

Protected cardiac surgery with st-MCS using the Impella 5.x is safe and feasible when applied in high-risk mitral valve surgery without st-MCS-related complications, resulting in excellent outcomes. This strategy might offer an alternative and comprehensive approach for the treatment of patients with mitral regurgitation in advanced heart failure, deemed ineligible for TEER or with need of concomitant surgery.

Role of acute mechanical circulatory support devices in cardiogenic shock

Cardiogenic shock is a state of low cardiac output that is associated with significant morbidity and mortality. A considerable proportion of patients with cardiogenic shock respond poorly to medical management and require acute mechanical circulatory support (AMCS) devices to improve tissue perfusion as well as to support the heart. In the last two decades, many new AMCS devices have been introduced to support the right, left, and both ventricles. All these devices vary in terms of the support they provide to the body and heart, mechanism of functioning, method of insertion, and adverse events. In this review, we compare and contrast the available percutaneous and surgically placed AMCS devices used in cardiogenic shock and discuss the associated clinical and hemodynamic data to make a conscious decision about choosing a device.

Temporary Mechanical Circulatory Support: Left, Right, and Biventricular Devices

Temporary mechanical circulatory support (MCS) encompasses a wide array of invasive devices, which provide short-term hemodynamic support for multiple clinical indications. Although initially developed for the management of cardiogenic shock, indications for MCS have expanded to include prophylactic insertion prior to high-risk percutaneous coronary intervention, treatment of acute circulatory failure following cardiac surgery, and bridging of end-stage heart failure patients to more definitive therapies, such as left ventricular assist devices and cardiac transplantation. A wide variety of devices are available to provide left ventricular, right ventricular, or biventricular support. The choice of a temporary MCS device requires consideration of the clinical scenario, patient characteristics, institution protocols, and provider familiarity and training. In this review, the most common forms of left, right, and biventricular temporary MCS are discussed, along with their indications, contraindications, complications, cannulations, hemodynamic effects, and available clinical data.