A newly developed transaortic axial flow ventricular assist device: Early clinical experience

Surgically implanted endovascular, microaxial left ventricular assist device: A single institution study

Objective

The Impella 5.5 (Abiomed, Inc), a surgically implanted endovascular microaxial left ventricular assist device, is increasingly used worldwide and there have been more than 10,000 implants. The purpose of this study is to describe a large-volume, single-center experience with the use of the Impella 5.5.

Methods

Data were obtained retrospectively from patients supported with the Impella 5.5 implanted at our institution from May 1, 2020, to December 31, 2022. Demographic, operative, and postoperative outcomes for each group are described. Results are reported in median (interquartile range) or n (%). The entire cohort was divided into 5 main groups based on the intention to treat at the time of the Impella 5.5 implantation: (1) patients who had a planned Impella 5.5 implanted at the time of high-risk cardiac surgery; (2) patients with cardiogenic shock; (3) patients bridged to a durable left ventricular assist device; (4) patients bridged to transplant; and (5) patients with postcardiotomy shock who received an unplanned Impella 5.5 implant.

Results

A total of 126 patients were supported with the Impella 5.5. Overall survival to device explant was 76.2%, with 67.5% surviving to discharge. Midterm survival was assessed with a median follow-up time of 318 days and demonstrated an overall survival of 60.3% and a median of 650 days (549-752).

Conclusions

Outcomes after using the Impella 5.5 are variable depending on the indication of use. Patient selection may be of utmost importance and requires further experience with this device to determine who will benefit from insertion.

Impella 5.5 as a bridge to heart transplantation: Waitlist outcomes in the United States

OBJECTIVES

The 2018 United Network for Organ Sharing allocation policy change has led to a significant increase in the use of mechanical circulatory support devices in patients listed for orthotopic heart transplantation. However, there has been a paucity of data regarding the newest generation Impella 5.5, which received FDA approval in 2019.

METHODS

The United Network for Organ Sharing registry was queried for all adults awaiting orthotopic heart transplantation who received Impella 5.5 support during their listing period. Waitlist, device, and early post-transplant outcomes were assessed.

RESULTS

A total of 464 patients received Impella 5.5 support during their listing period with a median waitlist time of 19 days. Among them, 402 (87%) patients were ultimately transplanted, with 378 (81%) being directly bridged to transplant with the device. Waitlist death (7%) and clinical deterioration (5%) were the most common reasons for waitlist removal. Device complications and failure were uncommon (<5%). The most common post-transplant complication was acute kidney injury requiring dialysis (16%). Survival at 1-year post-transplant survival was 89.5%.

CONCLUSION

Since its approval, the Impella 5.5 has been increasingly used as a bridge to transplant. This analysis demonstrates robust waitlist and post-transplant outcomes with minimal device-related and postoperative complications.

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.

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

Background: Patients with severely reduced LV-EF ≤ 30% undergoing CABG have a high risk for postoperative cardiogenic shock. The optimal timing of an adequate hemodynamic support has an impact on short- and midterm mortality after CABG. This study aimed to assess the prophylactic use of the Impella pump in high-risk patients undergoing elective cardiac surgery. Methods: In this single-center retrospective study, 14 patients with LV-EF (≤30%) undergoing cardiac surgery received a prophylactic, perioperative Impella (5.0, 5.5) support between 2020 and 2022. Results: The mean age at surgery was 64.2 ± 2.6 years, the mean preoperative LV-EF was 20.7% ± 1.56%. The duration of Impella support was 4 (3–7.8) days and the 30-day survival rate was 92.85%. Acute renal failure occurred in four patients who were dialyzed on average for 1.2 ± 0.7 days. Mechanical ventilation was needed for 1.75 (0.9–2.7) days. Time to inotrope/vasopressor independence was 2 (0.97–7.25) days with a highest lactate level (24 h postoperatively) of 3.8 ± 0.6 mmol/l. Postoperative LV-EF showed a significant improvement when compared to preoperative LV-EF (29.1% ± 2.6% vs. 20.7% ± 1.56% (p = 0.022)). Conclusion: The prophylactic Impella application seems to be a safe approach to improve the outcomes of this patient population.

Early experience with the Impella pump: Single-center registry

BACKGROUND

With the rapid development of mechanical circulatory support technologies, patients presenting with cardiogenic shock have gained access to various treatment opportunities which were not until recently available. The Impella® pump (Abiomed, Danvers, USA) is a minimally invasive device which provides excellent left ventricular unloading and full circulatory support. The aim of the study was to review our center's experience with Impella® and to analyze the major adverse events associated with the device.

METHODS

From January 2020 to January 2022, a total of 32 patients underwent Impella® implantation at our center for various indications.

RESULTS

The mean age at surgery was 60.3 ± 12.4 years and 9.4% were female. All patients presented with acute cardiogenic shock in INTERMACS Class I (53.1%) and INTERMACS Class II (46.9%). Twenty-six patients (81.25%) out of the whole cohort have been mobilized on Impella® support. Seventeen patients (53.1%) have been weaned from the Impella® support and 10 patients (31.3%) have been bridged to durable LVAD. The median time on Impella® was 7 days (IQR 5.0-11.0). 30-day mortality was 37.5%, with 56.25% survival until hospital discharge. Only one patient developed vascular complications consisting of arm hypoperfusion. There were no cases of stroke on Impella® support.

CONCLUSION

The Impella® axial-flow pump seems an appropriate therapeutic option for patients with acute cardiogenic shock requiring partial or full hemodynamic support. It also provides sufficient left ventricular unloading to allow full mobilization and neurological assessment of the patients. Furthermore, Impella® offers a high rate of myocardial recovery.

Bridge to transplantation from mechanical circulatory support: a narrative review

Objective

To highlight recent developments in the utilization of mechanical circulatory support (MCS) devices as bridge-to-transplant strategies and to discuss trends in MCS use following the changes to the United Network for Organ Sharing (UNOS) heart allocation system.

Background

MCS devices have played an increasingly important role in the treatment of heart failure patients. Over the past several years, technological advancements have led to new developments in MCS devices and expanding indications for MCS use. In October of 2018, the UNOS heart allocation policy was revised to prioritize higher-urgency patients, including those supported with temporary MCS devices. Since then, changes in trends of MCS utilization have been observed.

Methods

Articles from the PubMed database regarding the use of MCS devices as bridge-to-transplant strategies were reviewed.

Conclusions

Over the past decade, utilization of temporary MCS devices, which include the intra-aortic balloon pump (IABP), percutaneous ventricular assist devices (pVADs), and extracorporeal membrane oxygenation (ECMO), has become increasingly common. Recent advancements in MCS include the development of pVADs that can fully unload the left ventricle (LV) as well as devices designed to provide right-sided support. Technological advancements in durable left ventricular assist devices (LVADs) have also led to improved outcomes both on the device and following heart transplantation. Following the 2018 UNOS heart allocation policy revision, the utilization of temporary MCS in advanced heart failure patients has further increased and the proportion of patients bridged directly from a temporary MCS device has exponentially risen. However, following the start of the COVID-19 pandemic, the trends have reversed, with a decrease in the percentage of patients bridged from a temporary MCS device. As long-term data following the allocation policy revision becomes available, future studies should investigate how trends in MCS use for patients with advanced heart failure continue to evolve.