Concomitant temporary mechanical support in high‐risk coronary artery bypass surgery

Pearls and Pitfalls of Epicardial Echocardiography for Implantation of Impella CP Devices in Ovine Models

The Impella CP is a percutaneously inserted temporary left ventricular assist device used in clinical practice and in translational research into cardiogenic shock, perioperative cardiac surgery, acute cardiac failure and mechanical circulatory support. Fluoroscopic guidance is usually used for insertion of an Impella, thus limiting insertion to within catheterization laboratories. Transthoracic, transoesophageal and intracardiac echocardiography have been reported to guide Impella CP implantation with identified specific limitations stemming from the surgical, anatomical and equipment factors. We conducted translational prospective descriptive feasibility investigation as a part of two other hemodynamic Impella studies. It showed the successful application of epicardial echocardiographic scanning for implantation of Impella CP devices in ovine models, from which details of the technique and identified pitfalls are described with practical solutions for future investigators and clinicians. Many described findings are relevant to any other echocardiographic techniques when adequate imaging of the Impella and relevant anatomical structures is achievable.

Mechanical Circulatory Support During Surgical Revascularization for Ischemic Cardiomyopathy

BACKGROUND

This study aimed to describe the use of perioperative mechanical circulatory support (MCS) and its impact on outcomes in patients with ischemic cardiomyopathy who were undergoing surgical revascularization.

METHODS

Patients with an ejection fraction <35% who underwent isolated coronary artery bypass grafting (CABG) from 2015 to 2021 were identified (N = 378). Patients were divided into no MCS, preoperative MCS, and postoperative MCS groups on the basis of timing of MCS initiation, which included intraaortic balloon pump, extracorporeal membrane oxygenation, or Impella device (Abiomed) use. The primary outcome of interest was operative mortality.

RESULTS

The median Society of Thoracic Surgeons Predicted Risk of Mortality was 2.4%. Sixty-six percent (n = 246) of patients had a previous myocardial infarction, and 61.8% of these patients were within 21 days of CABG. Twenty-one patients (5.6%) presented in cardiogenic shock. The preoperative MCS cohort consisted of 31 patients (8.2%) who underwent CABG a median of 2 days after MCS initiation. Thirty (7.9%) patients required postoperative MCS. Independent risk factors for requiring postoperative MCS included the preoperative ejection fraction (odds ratio, 0.93; P = .01 and the presence of preoperative MCS (odds ratio, 3.06; P = .02). Overall, operative mortality was 3.4%, and 3-year survival was 87.0%. Operative mortality in patients who did and did not receive preoperative MCS was 7.7% and 2.9% (P = .12) with no difference in long-term survival (P = .80), whereas patients requiring postoperative MCS had significantly increased operative (16.7%) and late mortality (63%; P <.01).

CONCLUSIONS

CABG can be performed safely in patients with ischemic cardiomyopathy with selective use of perioperative MCS. Despite advanced disease severity, patients requiring preoperative MCS demonstrate acceptable short- and long-term survival. Patients requiring postoperative MCS have increased postoperative morbidity and mortality.

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.

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.

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.

Single center experience and early outcomes of Impella 5.5

Background

Acute decompensated heart failure (HF) and cardiogenic shock (CS) frequently are refractory to conservative treatment and require mechanical circulatory support (MCS). We report our early clinical experience and evaluate patient outcomes with the newer generation surgical Impella 5.5.

Methods

Seventy patients that underwent Impella 5.5 implantation between October 2019 and December 2021 at a single center were enrolled in this study. Pre-operative characteristics, peri-operative clinical course information, and post-operative outcomes were retrospectively collected.

Results

Fifty-seven (81%) patients survived to discharge, and 51 (76%) patients survived at the time of the first 30 days post-discharge visit. Thirty-one patients (44%) received Impella support for a bridge to advanced surgical heart failure therapy (transplant or durable left ventricular assist device [LVAD]), 27 (39%) cases were used for a bridge to recovery/decision and 12 (17.1%) cases was used for planned perioperative support for high-risk cardiac surgery procedure.

Conclusion

Our results suggest that Impella 5.5 provides favorable survival in the management of HF and CS, particularly used for a bridge to heart transplant or LVAD. Early extubation and mobilization with high flow circulatory support allowed effective tailoring of MCS approaches from peri-operative support for high-risk cardiac surgery, bridge to recovery, and to advanced surgical heart failure therapy.

Current status of perioperative temporary mechanical circulatory support during cardiac surgery

OBJECTIVES

We sought to determine utilization and outcomes of perioperative temporary mechanical circulatory support (tMCS) in the current practice of cardiac surgery.

BACKGROUND

tMCS is an evolving adjunct to cardiac surgery not fully characterized in contemporary practice.

METHODS

Using the nationwide inpatient sample we retrospectively analyzed hospital discharge data between January 1, 2016 and December 31, 2019. ICD-10-CM procedure codes were used to identify and divide patient hospitalizations into those who had preoperative tMCS (pre-tMCS) versus tMCS instituted the day of surgery or afterwards (sd/post-tMCS).

RESULTS

In all, 1,383,520 hospitalizations met inclusion criteria. 86,445 (6.25%) had tMCS. tMCS was utilized in 8.74% of coronary artery bypass grafting (CABG), 2.58% of isolated valve, and 9.71% of valve/CABG; operations. 29,325 (33.9%) had pre-tMCS while 57,120 (66.1%) had sd/post-tMCS. The use of tMCS was associated with greater inpatient mortality (15.66% vs. 1.53%, p < .001), longer length of stay (LOS) (14.4 vs. 8.5 days, p < .001), and higher mean inflation-adjusted costs ($93,040 ± 1038 vs. $51,358 ± 296, p < .001) compared to no use. Inpatient mortality (5.98% vs. 20.63%, p < .001), LOS (13.87 vs. 14.68, p < .001), and cost ($82,621 ± 1152 SEM vs. $98,381 ± 1242) were all significantly lower with pre-tMCS compared to sd/post tMCS. When analyzed separately, mortality was higher with later utilization of tMCS (5.98% pre, 17.1% sd, and 49.05% postsurgical date insertion, p < .001).

CONCLUSIONS

Perioperative tMCS is utilized in 6.25% of modern cardiac surgery, with two-thirds of cases instituted on the day of surgery or afterwards. The use of tMCS is associated with significantly higher mortality, longer LOS, and higher costs. Among patients undergoing tMCS, earlier utilization is associated with better outcomes.

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.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2021

This special article is the fourteenth in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the Editor-in-Chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series; namely, the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology. The major themes selected for 2021 are outlined in this introduction, and each highlight is reviewed in detail in the main body of the article. The literature highlights in the specialty for 2021 begin with an update on structural heart disease, with a focus on updates in arrhythmia and aortic valve disorders. The second major theme is an update on coronary artery disease, with discussion of both medical and procedural management. The third major theme is focused on the perioperative management of patients with COVID-19, with the authors highlighting literature discussing the impact of the disease on the right ventricle and thromboembolic events. The fourth and final theme is an update in heart failure, with discussion of diverse aspects of this area. The themes selected for this fourteenth special article are only a few of the diverse advances in the specialty during 2021. These highlights will inform the reader of key updates on a variety of topics, leading to improvement of perioperative outcomes for patients with cardiothoracic and vascular disease.

Concomitant ECMO And IABP Support in Postcardiotomy Cardiogenic Shock Patients

OBJECTIVES

Simultaneous mechanical circulatory support (MCS) with intra-aortic balloon pump (IABP) to extracorporeal membrane oxygenation (ECMO) is common in postcardiotomy cardiogenic shock (PCS). This study aimed to analyse the effect of concomitant ECMO and IABP therapy on the short-term outcomes of patients with PCS.

METHODS

Between March 2006 and March 2017, 172 consecutive patients with central (c) or peripheral (p) veno-arterial ECMO therapy due to PCS were identified at the current institution and included in this retrospective analysis. Patients were divided into ECMO+IABP and ECMO alone groups. Further, the impact of ECMO flow direction was analysed for the groups.

RESULTS

A total of 129 patients received ECMO+IABP support and 43 patients were treated with ECMO alone. Median ECMO duration did not differ between the groups (68 [34; 95] hours ECMO+IABP vs 44 [20; 103] hours ECMO; p=0.151). However, a trend toward a higher weaning rate was evident in ECMO+IABP patients (75 [58%] ECMO+IABP vs 18 [42%] ECMO; p=0.078). Concomitant IABP support with either cECMO (73% [n=24] cECMO+IABP vs 50% [n=11] ECMO; p=0.098) or pECMO (57% [n=55] ECMO+IABP vs 33% [n=7] ECMO; p=0.056) was also associated with a trend toward a higher weaning rate off ECMO. In-hospital mortality did not differ between the groups.

CONCLUSION

This analysis found that, independent of ECMO type, additional IABP support might increase ECMO weaning; however, it did not influence survival in PCS patients. Larger studies are necessary to further analyse the impact of this concomitant MSC therapy on clinical outcomes.

Oleocanthal protects against neuronal inflammation and cardiopulmonary bypass surgery-induced brain injury in rats by regulating the NLRP3 pathway

BACKGROUND

Open heart surgery is performed with the aid of cardiopulmonary bypass (CPB) techniques that may cause neuronal injuries.

OBJECTIVE

This study investigated the potential protective effect of oleocanthal pre-treatment against CPB-induced cerebral injury.

METHODS

Oleocanthal 30 mg/kg i.p. was administered 3 h before CPB induction in the treated group. Behavioral neurological scores and cerebral injury were assessed to determine the effects of oleocanthal, based on oxidative stress and serum mediators of inflammation by enzyme-linked immunosorbent assay (ELISA). Quantitative Polymerase Chain Reaction (qRT-PCR) was used to estimate the mRNA expression of Toll-like receptor 4 (TLR4) and Interleukin 1 Receptor Associated Kinase 4 (IRAK4) proteins in the cerebral tissue of rats CPB-induced injury. Western blot assay and histopathology were also performed.

RESULTS

The findings suggest that pre-treatment with oleocanthal reduced neurological dysfunction and cerebral injury. Parameters of oxidative stress and cytokine levels were reduced in the serum of the oleocanthal treated group compared with the CPB-only group. Pre-treatment with oleocanthal ameliorated the expression of TLR-4, IRAK4, and Zonula occludens-1 (ZO-1) proteins in the cerebral tissue of the CPB-injured rats.

CONCLUSIONS

The results revealed that treatment with oleocanthal protected against cerebral damage by controlling microglia inflammation through the TLR-4 pathway.

New Surgical Circulatory Support System Outcomes

Supplemental Digital Content is available in the text.

We report the first U.S. experience of the recently approved micro-axial surgical heart pump for the treatment of ongoing cardiogenic shock following acute myocardial infarction (AMICGS), postcardiotomy cardiogenic shock (PCCS), cardiomyopathy including myocarditis, high-risk percutaneous coronary intervention (HRPCI), and coronary artery bypass surgery (HRCABG). Demographic, procedural, hemodynamic, and outcome data were obtained from the manufacturer’s quality database of all Impella 5.5 implants at three centers. Fifty-five patients underwent an Impella 5.5 implant for cardiomyopathy (45%), AMICGS (29%), PCCS (13%), preop CABG (5%), OPCAB (4%), and other (4%). Thirty-five patients (63.6%) were successfully weaned off device with recovery of native heart function. Eleven patients (20.0%) were bridged to another therapy, two patients (3.6%) expired while on support, and in seven patients (12.7%) care was withdrawn. Overall survival was 83.6%. There were no device-related strokes, hemolysis, or limb ischemia observed. Four patients experienced purge sidearm damage, resulting in a pump stop in two patients. The new micro-axial surgical heart pump demonstrated successful clinical and device performance in providing both full hemodynamic support and ventricular unloading for patients with AMICGS, decompensated cardiomyopathy, and high-risk cardiac procedures. In this early U.S. experience, 83.6% of patients survived to explant with 76.1% of these patients recovering native heart function.

Temporary mechanical circulatory support prevents the occurrence of a low-output state in high-risk coronary artery bypass grafting: A case series

BACKGROUND

Coronary artery bypass grafting (CABG) is a durable treatment for coronary artery disease. Left ventricular dysfunction (LVD) (a division of cardiothoracic surgery) (ejection fraction < 35%) significantly elevates perioperative risk for patients pursuing surgical revascularization. Periprocedural support with temporary mechanical circulatory support (tMCS) has shown benefit in this patient population.

METHODS

Four patients with ischemic cardiomyopathy and LVD underwent CABG at our institution between 2017 and 2018. Each patient received perioperative ventricular support using a microaxial tMCS device (Impella 5.0®). The occurrence of a postoperative low-output state (LOS) was assessed for as well as postoperative morbidity and mortality, device-specific complications, and tMCS support duration.

RESULTS

All patients survived to device explant without device-related complications. Two patients required reoperation for nondevice-related bleeding. All patients were without an LOS at 24 h postoperatively with cardiac indices of 2.9-3.6 L/min/m² , normalized serum lactate, and vasoactive-inotrope scores of 0-12.0. There was a notably high incidence of acute renal failure (50%), which was observed in patients with preoperative cardiogenic shock. One patient died 10 days after the device explant. Of the three patients that survived to discharge, two were alive at the most recent follow-up. Postoperative device support varied widely (0-500 h).

CONCLUSION

Perioperative tMCS may be a viable strategy for preventing postoperative LOS in high-risk CABG patients with a low complication rate and acceptable morbidity. The application of microaxial tMCS devices in CABG is an area that warrants further investigation to delineate its impact on perioperative outcomes and potentially expand the indications for such devices.