Early Outcomes of the First 200 US Patients Treated with Impella 5.5: A Novel Temporary Left Ventricular Assist Device

A profile of the impella 5.5 for the clinical management of cardiogenic shock and a review of the current indications for use and future directions

INTRODUCTION

The Impella 5.5 device is a surgically inserted, trans-valvular, microaxial flow device capable of providing 5.5 L/min of continuous, antegrade flow from the left ventricle (LV) to the aorta. The ability of the Impella 5.5 to fully pressure and volume unload the dysfunctional LV while allowing for mobilization and rehabilitation has rapidly expanded its use. Clinical use scenarios include escalation of support for acute myocardial infarction cardiogenic shock (AMICS), transition from extracorporeal membrane oxygenation to mobile support, bridge to transplantation or durable MCS in acute decompensated heart failure, or perioperative use in post-cardiotomy cardiogenic shock (PCCS).

AREAS COVERED

This review provides a profile of the Impella 5.5 device, summarizes the current literature surrounding clinical applications, reviews active and upcoming clinical trials, and projects future applications for the device through an expert review.

EXPERT OPINION

The development of the Impella 5.5 has allowed for monitoring of left-heart recovery, optimizing right ventricular function, and rehabilitating patients to meet bridging endpoints. The 2018 heart transplant allocation system modifications have expanded the use of temporary mechanical circulatory support (tMCS) on the transplant waitlist, increasing the number of patients transplanted on support. With increased safety and durability, an expanding frontier is used in perioperative support for PCCS in high-risk cardiac surgery.

Use of Intravascular Micro-Axial Left Ventricular Assist Devices as a Bridging Strategy for Cardiogenic Shock: Mid-Term Outcomes

Objectives: Patients in cardiogenic shock (CS) may be successfully bridged using intravascular micro-axial left ventricular assist devices (M-LVADs) for recovery or determination of definitive therapy. Methods: One hundred and seven CS patients implanted with M-LVADs from January 2020 to May 2024 were divided into four groups; group-1: 34 patients (transplant); group-2: 25 patients (LVAD); group-3: 42 patients (postcardiotomy CS (PCCS)); group-4: 6 patients (decision/recovery but excluded from analysis). Multivariable logistic regression and Multivariable Coxregression models identified predictors of early -hospital and late mortality, and Odds ratios (ORs) and hazard ratios (HRs) with p < 0.05, respectively, were considered statistically significant. SPSS 29.0 and Python 3.11.1. were used for analyses. Results: Complications included device-malfunction (6%), gastrointestinal bleed (9%), long-term hemodialysis (21%), axillary hematoma requiring re-exploration (10%), heparin-induced thrombocytopenia (4%) requiring heparin therapy cessation/initiation of argatroban infusion, and non-fatal stroke (11%). Early hospital mortality included 13 patients: 2 in group-1, 1 in group-2, 10 in group-3 (p = 0.02). In the Logistic-Regression model, category of CS requiring an M-LVAD was significant (OR = 4.7, p = 0.05). Patients were followed for 4.5 years (mean follow-up was 23 ± 17 months), and 23 deaths occurred; group-1: 3 patients, group-2: 5 patients, and group-3: 15 patients (p = 0.019). At 4.5 years, actuarial survival was 90.7 ± 5.1% in group-1, 79.2 ± 8.3% in group-2, 62.8 ± 7.7% in group-3 (p = 0.01). In the Cox-Regression model, M-LVAD category (HR = 3.63, p = 0.04), and long-term postoperative dialysis (HR = 3.9, p = 0.002) emerged as predictors of long-term mortality. Conclusions: In cardiogenic shock, mid-term outcomes demonstrate good survival with M-LVADs as bridge to transplant/durable LVADs and reasonable survival with M-LVADs as a bridge to recovery following cardiotomy, accompanied by reduced ECMO usage, and early ambulation/rehabilitation.

Association between caseload volume and outcomes in left ventricular assist device implantations - a EUROMACS analysis

AIMS

This EUROMACS study was conducted with the primary aim of investigating the association between a centre's annual caseload and postoperative outcomes among patients undergoing left ventricular assist device (LVAD) implantation.

METHODS AND RESULTS

A total of 4802 patients identified between 2011 and 2020 from 35 participating centres were dichotomized based on the annual caseload of the treating centre at the time of device implant (≤30 vs. >30 LVAD implantations/year). The primary endpoint was 1-year survival. Secondary outcomes included overall survival analysis, device-related adverse events and readmissions. Cumulative follow-up was 10 003 patient-years, with a median follow-up of 1.54 years (interquartile range 0.52-3.15). Patients from higher volume centres more frequently presented in INTERMACS levels 1 and 2, suffered from right heart dysfunction and needed inotropic support. No difference was observed in adjusted 1-year survival. Adjusted overall survival probability was lower in higher volume centres (p = 0.002). In the subgroup analysis of HeartMate 3 devices only, higher volume centres were associated with decreased odds of 1-year survival (adjusted odds ratio 0.43, 95% confidence interval 0.20-0.97, p = 0.041). Similar findings were observed in the cumulative (i.e. learning curve) caseload analyses.

CONCLUSION

In patients undergoing LVAD implantation, centre volume was not associated with 1-year survival, but was related to device-related adverse events. Patient profiles differed with respect to centre size. These findings underscore the necessity for ongoing quality improvement initiatives in all centres, regardless of their annual caseload. Efforts are needed to standardize patient selection and preconditioning to further improve patient outcome.

Prolonged Impella 5.0/5.5 support within different pathways of care for cardiogenic shock: the experience of a referral center

Aims

Impella 5.0 and 5.5 are promising low-invasive left ventricle (LV) temporary mechanical circulatory supports (tMCS) for cardiogenic shock due to LV mechanical unloading and are paired with powerful hemodynamic support. This study aimed to analyze data and destinies of patients supported with Impella 5.0/5.5 at a national referral center for cardiogenic shock and to assess the parameters associated with myocardial recovery and successful weaning.

Methods

A single-center observational study was conducted on all patients treated with Impella 5.0 or 5.5 from March 2018 to July 2023.

Results

A total of 59 patients underwent Impella 5.0/5.5 implantation due to profound cardiogenic shock, with acute myocardial infarction being the most frequent cause of shock (42 patients, 71%). The median duration of Impella support was 13 days (maximum duration of 52 days). Axillary cannulation was feasible in almost all patients, and 36% were mobilized during support. A total of 44 patients (75%) survived to the next therapy/recovery: 21 patients experienced recovery and 15 and 8 were bridged to long-term LVAD and heart transplantation, respectively. The global survival rate was 66%. The predictors of native heart recovery at multivariate analysis were the number of days on tMCS before upgrade to Impella 5.0/5.5 [hazard ratio (HR) 0.68 (0.51-9) p = 0.0068] and improvement of LVEF within the first 7-10 days of support [HR 4.72 (1.34-16.7), p = 0.016].

Conclusions

Transcatheter systems such as Impella 5.0/5.5 revolutionized the field of tMCS. Myocardial recovery is the primary clinical target. Its prognostication and promotion are key to ensure the most proficuous course for each patient from cardiogenic shock to long-term event-free survival.

Impella 5.5: A Systematic Review of the Current Literature

OBJECTIVE

Impella 5.5 (Abiomed, Danvers, MA, USA) is a temporary mechanical circulatory support device used for patients in cardiogenic shock. This review provides a comprehensive overview of the device's clinical effectiveness, safety profile, patient outcomes, and relevant procedural considerations.

METHODS

We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed/MEDLINE database. The search query included articles available from October 6, 2022, through January 13, 2023. Our initial search identified 75 studies. All records were screened by 2 independent reviewers using the Covidence software for adherence to our inclusion criteria, and 8 retrospective cohort studies were identified as appropriate for inclusion.

RESULTS

Across the included studies, the sample size ranged from 4 to 275, with predominantly male cohorts. Indications for Impella support varied, and the duration of support ranged from 9.8 to 70 days. Overall, Impella support appeared to be associated with favorable survival rates and manageable complications in various patient populations. Complications associated with Impella use included bleeding, stroke, and device malfunctions. Two studies compared prolonged and Food and Drug Administration-approved Impella support, showing similar outcomes and adverse events.

CONCLUSIONS

Impella 5.5 continues to be an attractive option for bridging patients to definitive therapy. Survival during and after Impella 5.5 was favorable for patients regardless of initial indication. However, device use was associated with several important complications, which calls for judicious use and a precontemplated exit strategy. Limitations of this literature review include biases inherent to the retrospective studies included, such as selection and publication bias.

Escalation from intra-aortic balloon pump to axillary impella 5.5 support: Staged removal of the femoral access

Background: With the growing population of advanced heart failure, the use of Impella 5.5 has been increasing. Here, we report an effective strategy of removing the intra-aortic balloon pump (IABP) in the setting of escalation of support to Impella 5.5.Results: From January 1, 2022 to June 30, 2022, a total of 6 patients have undergone IABP removal during Impella 5.5 insertion. The IABP was subsequently removed over the long wire with manual compression on the femoral artery to control bleeding. An 8 or 9 Fr short sheath is inserted over the wire. Staged hemostasis was successfully performed in 4 patients, and the remaining two patients required escalation of support to veno-arterial membrane oxygenation as EC-PELLA utilizing the femoral arterial sheath.Conclusion: This does not only achieve secured hemostasis but also enables a smooth transition to further escalate support such as extracorporeal membrane oxygenation support, if necessary.

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.

Cardiogenic shock etiology and exit strategy impact survival in patients with Impella 5.5

BACKGROUND

Despite historical differences in cardiogenic shock (CS) outcomes by etiology, outcomes by CS etiology have yet to be described in patients supported by temporary mechanical circulatory support (MCS) with Impella 5.5.

OBJECTIVES

This study aims to identify differences in survival and post-support destination for these patients in acute myocardial infarction (AMI) and acute decompensated heart failure (ADHF) CS at a high-volume, tertiary, transplant center.

METHODS

A retrospective review of patients who received Impella 5.5 at our center from November 2020 to June 2022 was conducted.

RESULTS

Sixty-seven patients underwent Impella 5.5 implantation for CS; 23 (34%) for AMI and 44 (66%) for ADHF. AMI patients presented with higher SCAI stage, pre-implant lactate, and rate of prior MCS devices, and fewer days from admission to implantation. Survival was lower for AMI patients at 30 days, 90 days, and discharge. No difference in time to all-cause mortality was found when excluding patients receiving transplant. There was no significant difference in complication rates between groups.

CONCLUSIONS

ADHF-CS patients with Impella 5.5 support have a significantly higher rate of survival than patients with AMI-CS. ADHF patients were successfully bridged to heart transplant more often than AMI patients, contributing to increased survival.

Reconsidering FDA Guidelines: A Single-Center Experience of Prolonged Impella 5.5 Support

OBJECTIVE

Impella 5.5 (Abiomed, Danvers, MA, USA) is approved by the US Food and Drug Administration (FDA) for mechanical circulatory support for ≤14 days. It is unknown whether prolonged support is associated with worse outcomes. We sought to review our single-center experience with Impella 5.5 and compare outcomes based on support duration.

METHODS

We retrospectively reviewed adult patients (≥18 years old) supported with Impella 5.5 at our institution (May 2020 to April 2023). Patients on prolonged support (>14 days) were compared with those supported for ≤14 days.

RESULTS

There were 31 patients supported with Impella 5.5 including 14 (45.2%) supported >14 days. Median support duration for those on prolonged support was 43.5 (interquartile range [IQR] 25 to 63.5) days versus 8 (IQR 6, 13) days for those who were not (P < 0.001). Overall, the device-related complication rate was 9.7% and did not differ between groups (P = 0.08). Overall, 30-day postimplant survival was 71% and did not differ by support duration (P = 0.2). In-hospital mortality was 32% and did not differ between cohorts (P > 0.99). Among those surviving to explant (n = 22), long-term strategy included bridge to durable ventricular assist device (18%, n = 4), cardiac transplant (55%, n = 12), and cardiac recovery (27%, n = 6).

CONCLUSIONS

High-risk patients with cardiogenic shock may be supported with Impella 5.5 beyond the FDA-approved duration without increased risk of complications or mortality.

Short-term percutaneous mechanical circulatory support: no promise without positioning!

Short-term percutaneous mechanical circulatory support by a micro-axial flow pump is increasingly used to support the left ventricle in cardiogenic shock. After a correct indication and placement, appropriate device management in the cardiac intensive care unit is vital to ensure optimal pump function and adequate haemodynamic support. A key element hereby is a correct percutaneous ventricular assist device (pVAD) position. This review explains how an optimal left-sided pVAD position can be achieved and maintained, focusing on the correct insertion depth and rotational angle. Useful imaging techniques, placement and replacement manoeuvres, and monitoring options through the console are discussed. The frequently encountered problem of mal-rotation towards the mitral valve, which may cause suction alarms, haemolysis, aortic regurgitation, and inadequate haemodynamic support, is explained. Finally, a practical bedside approach to assess pVAD position and discern suction alarms due to mal-positioning from haemodynamic problems is proposed.

Stroke and Mechanical Circulatory Support in Adults

PURPOSE OF THE REVIEW

Short-term and durable mechanical circulatory support (MCS) devices represent life-saving interventions for patients with cardiogenic shock and end-stage heart failure. This review will cover the epidemiology, risk factors, and treatment of stroke in this patient population.

RECENT FINDINGS

Short-term devices such as intra-aortic balloon pump, Impella, TandemHeart, and Venoatrial Extracorporal Membrane Oxygenation, as well as durable continuous-flow left ventricular assist devices (LVADs), improve cardiac output and blood flow to the vital organs. However, MCS use is associated with high rates of complications, including ischemic and hemorrhagic strokes which carry a high risk for death and disability. Improvements in MCS technology have reduced but not eliminated the risk of stroke. Mitigation strategies focus on careful management of anti-thrombotic therapies. While data on therapeutic options for stroke are limited, several case series reported favorable outcomes with thrombectomy for ischemic stroke patients with large vessel occlusions, as well as with reversal of anticoagulation for those with hemorrhagic stroke. Stroke in patients treated with MCS is associated with high morbidity and mortality. Preventive strategies are targeted based on the specific form of MCS. Improvements in the design of the newest generation device have reduced the risk of ischemic stroke, though hemorrhagic stroke remains a serious complication.

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.

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.

Sodium bicarbonate as a local adjunctive agent for limiting platelet activation, aggregation, and adhesion within cardiovascular therapeutic devices

Cardiovascular therapeutic devices (CTDs) remain limited by thrombotic adverse events. Current antithrombotic agents limit thrombosis partially, often adding to bleeding. The Impella® blood pump utilizes heparin in 5% dextrose (D5W) as an internal purge to limit thrombosis. While effective, exogenous heparin often complicates overall anticoagulation management, increasing bleeding tendency. Recent clinical studies suggest sodium bicarbonate (bicarb) may be an effective alternative to heparin for local anti-thrombosis. We examined the effect of sodium bicarbonate on human platelet morphology and function to better understand its translational utility. Human platelets were incubated (60:40) with D5W + 25 mEq/L, 50 mEq/L, or 100 mEq/L sodium bicarbonate versus D5W or D5W + Heparin 50 U/mL as controls. pH of platelet-bicarbonate solutions mixtures was measured. Platelet morphology was examined via transmission electron microscopy; activation assessed via P-selectin expression, phosphatidylserine exposure and thrombin generation; and aggregation with TRAP-6, calcium ionophore, ADP and collagen quantified; adhesion to glass measured via fluorescence microscopy. Sodium bicarbonate did not alter platelet morphology but did significantly inhibit activation, aggregation, and adhesion. Phosphatidylserine exposure and thrombin generation were both reduced in a concentration-dependent manner-between 26.6 ± 8.2% (p = 0.01) and 70.7 ± 5.6% (p < 0.0001); and 14.0 ± 6.2% (p = 0.15) and 41.7 ± 6.8% (p = 0.03), respectively, compared to D5W control. Platelet aggregation via all agonists was also reduced, particularly at higher concentrations of bicarb. Platelet adhesion to glass was similarly reduced, between 0.04 ± 0.03% (p = 0.61) and 0.11 ± 0.04% (p = 0.05). Sodium bicarbonate has direct, local, dose-dependent effects limiting platelet activation and adhesion. Our results highlight the potential utility of sodium bicarbonate as a locally acting agent to limit device thrombosis.

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.

Impella devices: a comprehensive review of their development, use, and impact on cardiogenic shock and high-risk percutaneous coronary intervention

INTRODUCTION

Impella devices have emerged as a critical tool for temporary mechanical circulatory support (TMCS) in the management of cardiogenic shock (CS) and high-risk percutaneous coronary interventions (PCI). The purpose of this review is to examine the history of the different Impella devices, their hemodynamic profiles, and how the data supports their use.

AREAS COVERED

This review covers the development and specifications of the Impella 2.5, Impella CP, Impella 5.0/Left Direct (LD), Impella RP, and Impella 5.5 devices. This review also covers the clinical trials that illuminate the Impella devices' use in their appropriate clinical contexts. These studies examine the effectiveness of Impella devices and have begun to yield promising results, demonstrating improved survival rates when compared to the historically high mortality rates associated with CS. It is important to weigh the benefits of Impella devices in light of their contraindications. A literature search was conducted by searching the PubMed database for reviews, meta-analyses, and clinical trials pertinent to Impella devices.

EXPERT OPINION

Impella devices are a crucial tool for management of patients undergoing high-risk PCI and those with CS. There is evidence that early Impella implantation is beneficial in the treatment of patients presenting with CS. Further randomized controlled trials are needed to better elucidate the benefits of Impella devices in various clinical settings.

Extended Support With the Impella 5.5: Transplant, ECMO, and Complications

We report midterm results of Impella 5.5 use with focus placed on bridge-outcomes, venoarterial extracorporeal membrane oxygenation (VA-ECMO) transition, complications, and risk factors for mortality. A retrospective review of patients implanted with the Impella 5.5 at our medical center was conducted. Forty patients were included with varying bridge strategies. Sixteen (40%) patients were supported for <14 days, 13 (32.5%) for 14-30 days, and 11 (27.5%) for >30 days. Thirty day mortality was 22.5% (9/40). Twenty-five (62.5%) were successfully bridged to transplant or durable left ventricular assist device (LVAD), while four (10.0%) recovered without the need for any further cardiac support. Five of 11 (60%) patients initially supported with VA-ECMO were either transitioned to durable left ventricular assist device (dLVAD; n = 3, 27.3%), transplanted (n = 1, 9.1%), or recovered (n = 1, 9.1%). Of nine patients with >moderate right ventricle (RV) dysfunction, five (55.6%) were successfully bridged to transplant or LVAD. Five (12.5%) patients required interval cannulation to VA-ECMO, often in the setting of RV dysfunction, and all (100%) were successfully transplanted. Lower pulmonary artery (PA) systolic pressure ( P = 0.029), among other factors, was associated with mortality. In summary, the Impella 5.5 may be able to effectively stabilize patients in refractory left ventricular predominant cardiogenic shock for extended durations, allowing time for mechanical circulatory support (MCS) and transplant evaluations.

Bridging with surgically placed microaxial left ventricular assist devices: a high-volume centre experience

OBJECTIVES

The Impella 5.0 and 5.5 have largely superseded non-ambulatory temporary mechanical support devices; yet, clinical outcomes are predominantly limited to small series: this study presents the experience of a high-volume centre.

METHODS

An institutional clinical registry was used to identify all patients with cardiogenic shock who underwent Impella 5.0 or 5.5 implantation from January 2014 to March 2022. The primary outcome was survival to device explantation.

RESULTS

The study cohort comprised 221 patients, including 146 (66.1%) Impella 5.0 and 75 (33.9%) Impella 5.5 patients. The primary aetiology was non-ischaemic cardiomyopathy (50.7%, n = 112), ischaemic cardiomyopathy (23.1%, n = 51) and acute myocardial infarction (26.2%, n = 58). Patients were prospectively classified according to strategy as bridge to transplant (47.5%, n = 105), bridge to durable device (13.6%, n = 30) or bridge to recovery (38.9%, n = 86). Patients were predominantly Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2 (95.0%, n = 210). The median bridging duration was 14 (range 0-137) days. Device exchange, Ischaemic stroke and ipsilateral arm ischaemia occurred in 8.1% (n = 18), 2.7% (n = 6) and 1.8% (n = 4) of patients, respectively. Compared to the 75 most recent Impella 5.0 patients, Impella 5.5 patients (n = 75) had lower rates of device exchange (4.0%, n = 3 vs 13.3%, n = 10, P = 0.04). Overall, 70.1% (n = 155) of patients survived to Impella explantation.

CONCLUSIONS

The Impella 5.0 and 5.5 provide safe and effective temporary mechanical support in appropriately selected patients with cardiogenic shock. The newer device generation may have a lower requirement for device exchange as compared to its predecessor.

Outcomes of surgical Impella placement in acute cardiogenic shock

Introduction

Although a role for percutaneous Impella devices has been established, there is a paucity of data regarding the utility and outcomes of larger surgically implanted Impella devices.

Methods

We conducted a retrospective review of all surgical Impella implants at our institution. All Impella 5.0 and Impella 5.5 devices were included. The primary outcome was survival. Secondary outcomes included hemodynamic and end-organ perfusion as well as commonly encountered surgical complications.

Results

From 2012 to 2022, 90 surgical Impella devices were implanted. The median age was 63 [53-70] years, the mean creatinine was 2.07 ± 1.22 mg/dL, and the average lactate level was 3.32 ± 2.90 mmol/L. Prior to implantation, 47 patients (52%) were supported with vasoactive agents, while 43 (48%) were also supported with another device. The most common etiology of shock was acute on chronic heart failure (50, 56%), followed by acute myocardial infarction (22, 24%), and postcardiotomy (17, 19%). Overall, 69 patients (77%) survived to device removal, and 57 (65%) survived to hospital discharge. One-year survival was 54%. Neither etiology of heart failure nor device strategy was associated with 30-day or 1-year survival. On multivariable modeling, the number of vasoactive medications prior to device implantation was strongly associated with 30-day mortality (hazard ratio 1.94 [1.27-2.96], P < 0.01). Surgical Impella placement was associated with a significant decreased need for vasoactive infusions (P < 0.01) and decreased acidosis (P = 0.01).

Conclusions

Surgical Impella support for patients in acute cardiogenic shock is associated with lower vasoactive medication use, improved hemodynamics, increased end-organ perfusion, and acceptable morbidity and mortality.

Unloading the Left Ventricle in Venoarterial ECMO: In Whom, When, and How?

Venoarterial extracorporeal membrane oxygenation provides cardiorespiratory support to patients in cardiogenic shock. This comes at the cost of increased left ventricle (LV) afterload that can be partly ascribed to retrograde aortic flow, causing LV distension, and leads to complications including cardiac thrombi, arrhythmias, and pulmonary edema. LV unloading can be achieved by using an additional circulatory support device to mitigate the adverse effects of mechanical overload that may increase the likelihood of myocardial recovery. Observational data suggest that these strategies may improve outcomes, but in whom, when, and how LV unloading should be employed is unclear; all techniques require balancing presumed benefits against known risks of device-related complications. This review summarizes the current evidence related to LV unloading with venoarterial extracorporeal membrane oxygenation.

Improved clinical outcomes associated with the Impella 5.5 compared to the Impella 5.0 in contemporary cardiogenic shock and heart failure patients

A redesigned surgically implanted heart pump incorporates several design changes from the prior device generation, but no published comparative data demonstrate if these changes translate to improved outcomes. We retrospectively compared clinical characteristics and outcomes, drawn from an FDA-mandated QA database, for contemporary patients treated with the Impella 5.5 or Impella 5.0 for acute myocardial infarction complicated by cardiogenic shock (AMICS), cardiomyopathy, or postcardiotomy cardiogenic shock (PCCS). A total of 1238 patients at 290 US sites were included for analysis. Patients receiving the Impella 5.5 had significantly higher survival through explant (i.e., successfully weaned or bridged to heart replacement therapy) than those receiving the Impella 5.0 in all 3 settings: AMICS (70.5% vs 56.8%; p = 0.005), cardiomyopathy (88.1% vs 76.9%; p = 0.001), and PCCS (76.1% vs 55.7%; p = 0.003). Duration of support was significantly longer for Impella 5.5 patients with AMICS (9.2 vs 6.1 days; p = 0.008) and cardiomyopathy (10.7 vs 8.1 days; p < 0.001).

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.

Waitlist and transplant outcomes for patients bridged to heart transplantation with Impella 5.0 and 5.5 devices

BACKGROUND

Impella devices are increasingly utilized as a bridge to heart transplantation (BTT) and are now prioritized as Status 2 under the current heart allocation policy. This study evaluated waitlist and post-transplant outcomes of patients supported with Impella 5.0/5.5 devices.

METHODS

The United Network of Organ Sharing registry was used to identify adults waitlisted or transplanted with Impella 5.0 or 5.5 devices from 2010 to 2021. Separate analyses were performed for waitlist and transplantation outcomes for patients supported by Impella 5.0/5.5 devices. Competing outcomes for the waitlist analysis included rates of transplantation, recovery, and death or clinical deterioration. Among patients undergoing transplantation, the primary outcome was 1-year survival. Secondary outcomes included rates of rejection, new postoperative dialysis, stroke, and pacemaker implantation after transplantation.

RESULTS

There were 344 patients waitlisted and 394 patients transplanted with an Impella 5.0 (n = 212 and 251) or 5.5 (n = 132 and 143) device. Competing risk regression demonstrated similar likelihood of transplant (subhazard ratio [SHR], 1.33 (0.98-1.81, p = 0.067)) and similar likelihood of death or clinical deterioration (SHR, 0.67 [0.27-1.69, p = 0.400]) for Impella 5.5 patients. In the transplanted cohort, unadjusted 1-year post-transplant survival was comparable at 91.3% versus 94.6% (log-rank p = 0.661) for patients supported by Impella 5.0 or 5.5 device, respectively, a finding that persisted after risk-adjustment (HR 1.22, p = 0.699). Post-transplant complication rates were also comparable between 5.0 and 5.5 patients.

CONCLUSIONS

Impella devices can be used as a BTT with excellent survival and minimal post-transplant morbidity. Outcomes were comparable for Impella 5.0 and 5.5 devices.

Microaxial Left Ventricular Assist Device in Cardiogenic Shock: A Systematic Review and Meta-Analysis

Microaxial left ventricular assist devices (LVAD) are increasingly used to support patients with cardiogenic shock; however, outcome results are limited to single-center studies, registry data and select reviews. We conducted a systematic review and meta-analysis, searching three databases for relevant studies reporting on microaxial LVAD use in adults with cardiogenic shock. We conducted a random-effects meta-analysis (DerSimonian and Laird) based on short-term mortality (primary outcome), long-term mortality and device complications (secondary outcomes). We assessed the risk of bias and certainty of evidence using the Joanna Briggs Institute and the GRADE approaches, respectively. A total of 63 observational studies (3896 patients), 6 propensity-score matched (PSM) studies and 2 randomized controlled trials (RCTs) were included (384 patients). The pooled short-term mortality from observational studies was 46.5% (95%-CI: 42.7–50.3%); this was 48.9% (95%-CI: 43.8–54.1%) amongst PSM studies and RCTs. The pooled mortality at 90 days, 6 months and 1 year was 41.8%, 51.1% and 54.3%, respectively. Hemolysis and access-site bleeding were the most common complications, each with a pooled incidence of around 20%. The reported mortality rate of microaxial LVADs was not significantly lower than extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pumps (IABP). Current evidence does not suggest any mortality benefit when compared to ECMO or IABP.

Impella 5.5 Support beyond 50 Days as Bridge to Heart Transplant in End-Stage Heart Failure Patients

Prolonged mechanical circulatory support (MCS) for severe left ventricular dysfunction in cardiogenic shock as a bridge to heart transplantation (HTx) generally requires a surgical procedure. Typically, a surgically implanted temporary extracorporeal left ventricular assist device (LVAD) is chosen because of superior flow and durability compared with a percutaneously delivered endovascular LVAD (pVAD). However, compared with its predecessors, the Impella 5.5 trans-valvular pVAD provides higher hemodynamic support and features improved durability. Here, we present four successful cases with prolonged Impella 5.5 support as a bridge to HTx, with a mean support duration of 70 days (maximum 83 days). These cases highlight several potential benefits of Impella 5.5. The minimally invasive implantation procedure of the device reduces bleeding, decreases the postoperative recovery period, and enables early patient ambulation to reduce physical deconditioning before HTx surgery. Furthermore, Impella 5.5 adequately unloads the left ventricle and provides hemodynamic support to maintain end-organ function to further optimize hemodynamics before HTx. The evolution of Impella 5.5 technology may provide an alternative bridging strategy to traditional surgically implanted temporary MCS in select cases.

Hemolysis during short-term mechanical circulatory support: from pathophysiology to diagnosis and treatment

INTRODUCTION

Despite advances in heart failure therapies and percutaneous coronary interventions, survival for cardiogenic shock remains poor. Percutaneous ventricular assist devices (pVAD) are increasingly used, but current evidence remains conflicting. The Impella is an example of such a device, based on a catheter mounted micro-axial continuous flow pump, that has been rapidly adopted in routine practice. An important aspect in the post implantation care is the prevention of complications. Hemolysis is one of the more frequent complications seen with this device.

AREAS COVERED

In this review we discuss the pathophysiology, diagnosis and treatment of hemolysis in patients supported with a pVAD. A practical algorithm for rapid identification of hemolysis and the underlying cause is presented, allowing for early treatment and prevention of further complications.

EXPERT OPINION

Hemolysis remains a threat to patients supported with any mechanical circulatory support device. Prevention as well as treatment demands for sufficient knowledge about the device, the optimal position and hemodynamics. Future studies should try to clarify some of the elements that are still unclear such as optimal anticoagulation, the place of pentoxyfilline or extracorporeal removal of free hemoglobin. This could help to optimize outcomes in clinical practice as well as future studies.

High flow from Impella 5.5 with partial veno-arterial extracorporeal membrane oxygenation support: Case series

Optimal flow balance between Impella 5.5 and veno-arterial extracorporeal membrane oxygenation (ECMO) support in the setting of EC-PELLA (ECMO+Impella) is unknown. Outcomes of high Impella 5.5 flow in the setting of EC-PELLA support were reviewed (N = 7). EC-PELLA was successfully explanted in 6 patients (bridge-to-transplant, N = 1; bridge-to-recovery, N = 5). The median duration of EC-PELLA support in explanted patients was 6 days. Survival at discharge was 71.4% (5 patients). In terms of device-related events, either VA-ECMO or Impella-related complications were not experienced. The median performance level of Impella 5.5 was P5 at the time of starting EC-PELLA support and then increased with time up to the median of P8 with increment of the Impella flow, and index (L/min/m² ). The percentage of Impella flow per total EC- PELLA flow reached 50% after 48 h of support. The vasoactive-inotropic score and serum lactate level improved after institution of EC-PELLA support as well as the pulmonary artery pressures and central venous pressure. In conclusion, a high pump flow from Impella 5.5 with partial VA-ECMO support in the setting of EC-PELLA provided great support with favorable survival and device-related complications rate.

Destination left ventricular assist devices in island states: asking too much or the inevitable solution

Background

Destination left ventricular assist device placement is increasing as a result of donor shortages and changing patient attitudes. As organ shortages become critical, LVAD programs become fundamental even in more remote regions of the world including island states. Here, we provide a look into the current state and availability of LVAD programs in island states.

Main body

A narrative review was performed using the World Health Organization Global Index Medicus and PubMed/MEDLINE databases to identify articles describing the island states having reported LVAD placements and programs. Additionally, INTERMACS reports were used. Data were retrieved and a review is presented describing the current state of LVADs in island states. The Caribbean region as a whole has a heart failure (HF) prevalence of 814 per 100,000 and Oceania 667 per 100,000 people. We estimate that over 3000 people in these islands need either a heart transplant or an LVAD.

Short conclusion

For HF patients living in island regions, special attention should be paid to the inability of having access to specialized mainland medical care. The continuous quest for a solution to HF in island regions should include the establishing of high-quality LVAD programs in a transfer-network centralized/regionalized system to care for those patients not candidates for long-distance air-bridging.

Use of a novel bicarbonate-based Impella 5.5 purge solution in a coagulopathic patient

The Impella 5.5 with Smart Assist (Abiomed) is a life-saving treatment option in acute heart failure which utilizes a continuous heparin purge solution to prevent thrombosis. In patients with contraindications to heparin, alternative anticoagulation strategies are required. We describe the stepwise management of anticoagulation in a coagulopathic patient with persistent cardiogenic shock following a coronary artery bypass procedure who underwent Impella 5.5 placement. A direct thrombin inhibitor-based purge solution was utilized while evaluating for heparin-induced thrombocytopenia. The use of a novel bicarbonate-based purge solution (BBPS) was successfully used due to severe coagulopathy. There were no episodes of pump thrombosis or episodes of severe bleeding on the BBPS and systemic effects of alkalosis and hypernatremia were minimal.