Direct bridging to cardiac transplantation with the surgically implanted Impella 5.0 device

The Increasing Utilization of the Impella Device as a Bridge-to-Transplantation in Pediatric Heart Centers Across the United States

ObjectiveReports on the use of the Impella device in children undergoing heart transplantation have been limited. We sought to provide what is to our knowledge the first multi-institutional national report of pediatric Impella device utilization as a bridge-to-heart transplant strategy.MethodsAll patients (<18 years) who underwent Impella placement in the United Network for Organ Sharing (UNOS) from the first use in 2013 to June 2024 were identified. Descriptive analysis was performed, and posttransplant survival analyzed using Kaplan-Meier survival analysis.ResultsFifty children who underwent Impella placement were identified. All UNOS regions utilized the Impella device in pediatric patients. The earliest use was in 2013. Starting in 2022, use as a bridge-to-transplantation experienced a more than two-fold increase, with a consistent rise to 11 devices in 2023 and 10 devices as of June 2024. The median age at Impella implantation was 15 years [13-17]. The median weight was 61 kg [48-82], and the median height was 167 cm [153-172]. The most frequent listing diagnosis was cardiomyopathy (N = 35/50, 70%), followed by congenital heart disease (N = 10/50, 20%). The median device duration was 12 days [6-21], and among all 50 children, 84% (N = 42) underwent heart transplantation the one-year survival was 94.45% [91.23%-97.59%].ConclusionThis report demonstrates the diverse and increasing use of the Impella device as a bridge-to-heart transplantation strategy in children. While early outcomes are promising, investigation is warranted to understand how this less invasive and versatile device can maximize outcomes for children.

Extended Duration of Impella 5.5 Support Does Not Adversely Impact Outcomes Following Heart Transplantation: A National Registry Analysis

Prior studies assessing the effects of Impella 5.5 support duration on posttransplant outcomes have been limited to single-center case reports and series. This study evaluates the impact of Impella 5.5 support duration on outcomes following heart transplantation using the United Network for Organ Sharing database. Adult heart transplant recipients who were directly bridged to primary isolated heart transplantation with Impella 5.5 were included. The cohort was stratified into two groups based on the duration of Impella support: less than or equal to 14 and greater than 14 days. The primary outcome was 90 day posttransplant survival. Propensity score matching was performed. Sub-analysis was conducted to evaluate the impact of greater than 30 days of Impella support on 90 day survival. Three hundred thirty-two recipients were analyzed. Of these, 212 recipients (63.9%) were directly bridged to heart transplantation with an Impella support duration of greater than 14 days. The two groups had comparable 90 day posttransplant survival and complication rates. The comparable posttransplant survival persisted in a propensity score-matched comparison. In the sub-analysis, Impella support duration of greater than or equal to 30 days did not adversely impact 90 day survival. This study demonstrates that extended duration of support with Impella 5.5 as a bridge to transplantation does not adversely impact posttransplant outcomes. Impella 5.5 is a safe and effective bridging modality to heart transplantation.

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.

Temporary mechanical circulatory support as a bridge to transplant in peripartum cardiomyopathy

Background

Use of temporary mechanical circulatory support (tMCS) for peripartum cardiomyopathy (PPCM) shock has been described in small cohorts, but not on a national scale. This study compares tMCS, durable MCS (dMCS), and no MCS as bridge to transplant strategies for PPCM.

Methods

Female patients ≥14 years, listed for first-time isolated heart transplant (HT) between January 1, 2000 and June 30, 2021, were identified in the United Network for Organ Sharing database. Patients were stratified by receipt of MCS at any point during the waitlist period. Patients on multiple devices were excluded.

Results

A total of 1,043 PPCM patients were listed for HT, including 575 bridged on no MCS, 177 on tMCS, and 291 on dMCS. The tMCS cohort included 10 patients on extracorporeal membrane oxygenation, 113 on intra-aortic balloon pump, and 54 on nondischargeable ventricular assist device (VAD) or percutaneous device. The dMCS group primarily received durable VADs. Compared to dMCS, tMCS recipients were more likely to require inotropes, mechanical ventilation, and longer hospitalizations pretransplant (all p < 0.001). tMCS patients were more likely to be transplanted after 6 months than those on no device (adjusted subhazard ratio 1.57 [1.24-2.01]). Six hundred and eighty-one patients underwent HT. tMCS support was associated with similar 3-year graft survival compared to no MCS and dMCS (both p > 0.05). After multivariable risk adjustment, neither tMCS (adjusted hazard ratio 0.56 [0.06-5.43]) nor dMCS (adjusted hazard ratio 0.36 [0.05-2.82]) significantly predicted 3-year graft survival.

Conclusions

Compared to patients bridged to HT on dMCS or no MCS, PPCM patients receiving tMCS are higher acuity candidates but have equivalent post-transplant graft survival.

Guide to Temporary Mechanical Support in Cardiogenic Shock: Choosing Wisely

Cardiogenic shock is a multisystem pathology that carries a high mortality rate, and initial pharmacotherapies include the use of vasopressors and inotropes. These agents can increase myocardial oxygen consumption and decrease tissue perfusion that can oftentimes result in a state of refractory cardiogenic shock for which temporary mechanical circulatory support can be considered. Numerous support devices are available, each with its own hemodynamic blueprint. Defining a patient's hemodynamic profile and understanding the phenotype of cardiogenic shock is important in device selection. Careful patient selection incorporating a multidisciplinary team approach should be utilized.

Impella 5.5 Bridge to Heart Transplant: An Institutional Series and a Closer Look at Device Removal Technique

Limited donor organ availability often necessitates mechanical circulatory support, and recently the Impella 5.5, as a bridge to heart transplant. Of 175 Impella 5.5-supported patients at our institution, 45 underwent transplantation in the largest series to date, for whom we analyzed outcomes. Two methods of complete device explant were evaluated: central Impella transection and removal via axillary graft. Median Impella days were 25 (16-41); median waitlist days were 21 (9-37). Eighty-nine percent (40/45) of patients had device placement via right axillary artery. Seventy-six percent (34/45) underwent central transection for device removal. Four patients (8.9%) required short-term venoarterial extracorporeal membranous oxygenation (VA ECMO) postoperatively for primary graft dysfunction (PGD). Two patients (4.4%) suffered postoperative stroke. Five patients (11.1%) required new RRT postoperatively. One patient (2.2%) returned to the operating room (OR) for axillary graft bleeding. A higher chance of procedural complications was found with the axillary removal technique ( p = 0.014). Median intensive care unit (ICU) days, length of stay (LOS), and postoperative days to discharge were 46 (35-63), 59 (49-80), and 18 (15-24), respectively. Ninety-eight percent (44/45) survived to discharge. Thirty-day survival was 95.6% (43/45), with 1 year survival at 90.3% (28/31). Eighty-eight percent (37/42) remain without rejection. In our institutional experience, Impella 5.5 is a safe and reliable bridge to transplant.

Outcomes of Impella 5.0 and 5.5 for cardiogenic shock: A single-center 137 patient experience

BACKGROUND

This study evaluated the outcomes of patients with cardiogenic shock (CS) supported with Impella 5.0 or 5.5 and identified risk factors for in-hospital mortality.

METHODS

Adults with CS who were supported with Impella 5.0 or 5.5 at a single institution were included. Patients were stratified into three groups according to their CS etiology: (1) acute myocardial infarction (AMI), (2) acute decompensated heart failure (ADHF), and (3) postcardiotomy (PC). The primary outcome was survival, and secondary outcomes included adverse events during Impella support and length of stay. Multivariable logistic regression was performed to identify risk factors for in-hospital mortality.

RESULTS

One hundred and thirty-seven patients with CS secondary to AMI (n = 47), ADHF (n = 86), and PC (n = 4) were included. The ADHF group had the highest survival rates at all time points. Acute kidney injury (AKI) was the most common complication during Impella support in all 3 groups. Increased rates of AKI and de novo renal replacement therapy were observed in the PC group, and the AMI group experienced a higher incidence of bleeding requiring transfusion. Multivariable analysis demonstrated diabetes mellitus, elevated pre-insertion serum lactate, and elevated pre-insertion serum creatinine were independent predictors of in-hospital mortality, but the etiology of CS did not impact mortality.

CONCLUSIONS

This study demonstrates that Impella 5.0 and 5.5 provide effective mechanical support for patients with CS with favorable outcomes, with nearly two-thirds of patients alive at 180 days. Diabetes, elevated pre-insertion serum lactate, and elevated pre-insertion serum creatinine are strong risk factors for in-hospital mortality.

Microaxial mechanical circulatory support after orthotopic heart transplantation

AIM

Use of microaxial mechanical circulatory support (MCS) has been reported for severe graft rejection or dysfunction after heart transplantation (HTx). We aimed to assess utilization patterns of microaxial MCS after HTx in adolescents (ages 18 and younger) and adults (ages 19 and older).

METHODS

Electronic search was performed to identify all relevant studies on post-HTx use of microaxial support in adults and adolescents. A total of 18 studies were selected and patient-level data were extracted for statistical analysis.

RESULTS

All patients (n=23), including adults (n=15) and adolescents (n=8), underwent Impella (Abiomed, Danvers, MA) microaxial MCS after HTx. Median age was 36 [IQR 18-56] years (Adults, 52 [37-59]; adolescents, 16 [15-17]). Primary right ventricular graft dysfunction was an indication exclusively seen in the adults 40% (6/15), while acute graft rejection was present in 46.7% (7/15) of adults. Median time after transplant was 9 [0-32] months (Adults, 4 [0-32]; adolescents, 11 [4.5, 45]). Duration of Impella support was comparable between adults and adolescents (5 [2.5-8] vs 6 [5-8] days, p = 0.38). Overall improvement was observed both in median LV ejection fraction (23.5% [11.3-28] to 42% [37.8-47.3], p < 0.01) and cardiac index (1.8 [1.2-2.6] to 3 [2.5-3.1], p < 0.01). Retransplantation was required in four adolescents (50%, 4/8). Survival to discharge was achieved by 60.0% (9/15) of adults and 87.5% (7/8) of adolescents respectively (p = 0.37).

CONCLUSION

Indications for microaxial MCS appear to vary between adult and adolescent patients. Overall improvement in LVEF and cardiac index was observed, however, with suboptimal survival to discharge.

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.

Clinical outcomes of hundred large Impella implantations in cardiogenic shock patients based on individual clinical scenarios

BACKGROUND

Large Impella systems (5.0 or 5.5; i.e., Impella 5+) (Abiomed Inc., Danvers, MA, USA) help achieve better clinical outcomes through relevant left ventricular unloading in acute cardiogenic shock (CS). Here, we report our experience with Impella 5+, while focusing on the clinical outcomes depending on individual case scenarios in patients with acute CS.

METHODS

This single-center retrospective observational study included 100 Impella 5+ implantations conducted on patients with acute CS from November 2018 to October 2021. After excluding 10 reimplantation cases, 90 cases were enrolled for further analysis.

RESULTS

In-hospital and 30-day mortality rates were 56.7% (n = 51) and 48.9% (n = 44), respectively. In-hospital mortality was lower in patients with acute myocardial infarction (AMI) than in non-AMI patients (p = 0.07). Young age and low lactate levels were the independent predictors of successful transition and survival after permanent mechanical circulatory support/heart transplantation (pMCS/HTX) (age, p = 0.03; lactate level, p = 0.04; survived after pMCS/HTX, n = 11; died on Impella, n = 41). During simultaneous utilization of venoarterial extracorporeal membrane oxygenation therapy and Impella 5+, termed ECMELLA therapy, high dose of noradrenaline was a predictive factor for in-hospital mortality by multivariate analysis (n = 0.02).

CONCLUSIONS

Our results suggest that enhanced Impella support might have better clinical outcomes among acute CS patients supported with large Impella, those with AMI than those with no AMI. Young age and low lactate levels were predictors of successful bridging to pMCS/HTX and favorable clinical outcomes thereafter. The clinical outcomes of ECMELLA therapy might depend on noradrenaline dose at the time of Impella 5+ implantation.

Guide to Temporary Mechanical Support in Cardiogenic Shock: Choosing Wisely

Cardiogenic shock is a multisystem pathology that carries a high mortality rate, and initial pharmacotherapies include the use of vasopressors and inotropes. These agents can increase myocardial oxygen consumption and decrease tissue perfusion that can oftentimes result in a state of refractory cardiogenic shock for which temporary mechanical circulatory support can be considered. Numerous support devices are available, each with its own hemodynamic blueprint. Defining a patient's hemodynamic profile and understanding the phenotype of cardiogenic shock is important in device selection. Careful patient selection incorporating a multidisciplinary team approach should be utilized.

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.

Acute mechanical circulatory support for cardiogenic shock in India

Cardiogenic shock continues to have high morbidity and mortality, despite advances in the field. Temporary mechanical circulatory support (TMCS) devices, if instituted in a timely fashion, can help stabilize critically ill patients with cardiogenic shock from various aetiologies and cardiac arrest, and provide time for organ recovery or till durable support or transplantation can be achieved. Currently, several options for TMCS devices exist. In this review, we discuss indications, contraindications, characteristics of the various available devices, and important issues pertaining to their management.

Short-term outcomes of heart transplant patients bridged with Impella 5.5 ventricular assist device

AIMS

We sought to investigate the outcomes of heart transplant patients supported with Impella 5.5 temporary mechanical circulatory support.

METHODS AND RESULTS

Patient demographics, perioperative data, hospital timeline, and haemodynamic parameters were followed during initial admission, Impella support, and post-transplant period. Vasoactive-inotropic score, primary graft failure, and complications were recorded. Between March 2020 and March 2021, 16 advanced heart failure patients underwent Impella 5.5 temporary left ventricular assist device support through axillary approach. Subsequently, all these patients had heart transplantation. All patients were either ambulatory or chair bound during their temporary mechanical circulatory support until heart transplantation. Patients were kept on Impella support median of 19 days (3-31) with the median lactate dehydrogenase level of 220 (149-430). All Impella devices were removed during heart transplantation. During Impella support, patients had improved renal function with median creatinine serum level of 1.55 mg/dL decreased to 1.25 (P = 0.007), pulmonary artery pulsatility index scores increased from 2.56 (0.86-10) to 4.2 (1.3-10) (P = 0.048), and right ventricular function improved (P = 0.003). Patients maintained improved renal function and favourable haemodynamics after their heart transplantation as well. All patients survived without any significant morbidity after their heart transplantation.

CONCLUSIONS

Impella 5.5 temporary left ventricular assist device optimizes care of heart transplant recipients providing superior haemodynamic support, mobility, improved renal function, pulmonary haemodynamics, and right ventricular function. Utilizing Impella 5.5 as a direct bridging strategy to heart transplantation resulted in excellent outcomes.

Left ventricular assist device bridging to heart transplantation: Comparison of temporary versus durable support

BACKGROUND

Since the revision of the United States heart allocation system, increasing use of mechanical circulatory support has been observed as a means to support acutely ill patients. We sought to compare outcomes between patients bridged to orthotopic heart transplantation (OHT) with either temporary (t-LVAD) or durable left ventricular assist devises (d-LVAD) under the revised system.

METHODS

The United States Organ Network database was queried to identify all adult OHT recipients who were bridged to transplant with either an isolated t-LVAD or d-LVAD from 10/18/2018 to 9/30/2020. The primary outcome was 1-year post-transplant survival. Predictors of mortality were also modeled, and national trends of LVAD bridging were examined across the study period.

RESULTS

About 1,734 OHT recipients were analyzed, 1,580 (91.1%) bridged with d-LVAD and 154 (8.9%) bridged with t-LVAD. At transplant, the t-LVAD cohort had higher total bilirubin levels and greater prevalence of pre-transplant intravenous inotrope usage and mechanical ventilation. Median waitlist time was also shorter for t-LVAD. At 1 year, there was a non-significant trend of increased survival in the t-LVAD cohort (94.8% vs 90.1%; p = 0.06). After risk adjustment, d-LVAD was associated with a 4-fold hazards for 1-year mortality (hazard ratio 3.96, 95% confidence interval 1.42-11.03; p = 0.009). From 2018 to 2021, t-LVAD bridging increased, though d-LVAD remained a more common bridging strategy.

CONCLUSIONS

Since the 2018 allocation change, there has been a steady increase in t-LVAD usage as a bridge to OHT. Overall, patients bridged with these devices appear to have least equivalent 1-year survival compared to those bridged with d-LVAD.

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.

Rational and Initiative of the Impella in Cardiac Surgery (ImCarS) Register Platform

OBJECTIVES

 Cardiac support systems are being used increasingly more due to the growing prevalence of heart failure and cardiogenic shock. Reducing cardiac afterload, intracardiac pressure, and flow support are important factors. Extracorporeal membrane oxygenation (ECMO) and intracardiac microaxial pump systems (Impella) as non-permanent MCS (mechanical circulatory support) are being used increasingly.

METHODS

 We reviewed the recent literature and developed an international European registry for non-permanent MCS.

RESULTS

 Life-threatening conditions that are observed preoperatively often include reduced left ventricular function, systemic hypoperfusion, myocardial infarction, acute and chronic heart failure, myocarditis, and valve vitia. Postoperative complications that are commonly observed include severe systemic inflammatory response, ischemia-reperfusion injury, trauma-related disorders, which ultimately may lead to low cardiac output (CO) syndrome and organ dysfunctions, which necessitates a prolonged ICU stay. Choosing the appropriate device for support is critical. The management strategies and complications differ by system. The "heart-team" approach is inevitably needed.However despite previous efforts to elucidate these topics, it remains largely unclear which patients benefit from certain systems, when is the right time to initiate (MCS), which support system is appropriate, what is the optimal level and type of support, which therapeutic additive and supportive strategies should be considered and ultimately, what are the future prospects and therapeutic developments.

CONCLUSION

 The European cardiac surgical register ImCarS has been established as an IIT with the overall aim to evaluate data received from the daily clinical practice in cardiac surgery. Interested colleagues are cordially invited to join the register.

CLINICAL REGISTRATION NUMBER

 DRKS00024560.

POSITIVE ETHICS VOTE

 AZ 246/20 Faculty of Medicine, Justus-Liebig-University-Gießen.

Microaxial Left Ventricular Assist Device Versus Intraaortic Balloon Pump as a Bridge to Transplant

BACKGROUND

Heart transplantation (HTx) candidates supported by Impella (Abiomed, Danvers, MA) or intraaortic balloon pump (IABP), who demonstrate evidence of cardiogenic shock, may qualify for waitlist status 2 without exception under the new donor heart allocation system. However limited data comparing Impella versus IABP as a bridge to HTx exist.

METHODS

The United Network for Organ Sharing database was queried for adults listed and/or transplanted between January 2014 and February 2020. Temporal trends regarding Impella and IABP use were analyzed using the Royston trend test and χ² test. Waitlist mortality was examined using Fine-Gray competing risks analysis. Post-HTx 180-day survival was analyzed using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

Impella use increased from 0.2% in 2014 to 2.6% in 2020 (P < .01) and from 0.4% to 2.2% (P < .01) under the new allocation system. IABP use increased from 4.9% in 2014 to 27.6% in 2020 (P < .01) and from 6.7% to 26.6% (P < .01) under the new allocation system. Post-HTx survival was similar between groups (adjusted hazard ratio, 0.82; 95% CI, 0.38-1.78) despite more preoperative ventilation (3.6% vs 1.1%, P = .01) and higher model for end-stage liver disease excluding international normalized ratio scores (12.4 vs 9.5, P < .01) among Impella-supported recipients. Under the new system Impella-supported candidates were at higher risk of waitlist delisting compared with IABP-supported candidates (subhazard ratio, 2.42; 95% CI, 1.19-4.92).

CONCLUSIONS

Post-HTx survival is comparable between Impella-supported and IABP-supported recipients despite worse preoperative profiles among Impella-supported recipients. Higher risk of waitlist delisting among Impella-supported candidates under the new allocation system requires close attention.

Use of Impella in Patients Listed for Heart Transplantation

The new United Network for Organ Sharing (UNOS) policy has resulted in a significantly higher number of temporary mechanical circulatory support device usage such as extracorporeal membrane oxygenation, Impella, and intra-aortic balloon pump due to provision of higher priority with their use while on the waiting list. We aimed to identify Impella use in patients awaiting heart transplantation and temporal changes in its usage. The UNOS database was queried between years 2015 and 2019 for patients aged greater than or equal to 18 years, listed to undergo heart transplantation. A total of 378 patients had Impella support while listed for heart transplantation. Impella use skyrocketed from 2015 (1%) to 2019 (4%, p < 0.01). The most substantial increase in Impella use occurred after the UNOS policy change. The patients listed on Impella support after the policy change had significantly lower waiting time (median 12 days vs. 45 days, p < 0.01). More patients with Impella were directly transplanted (80% vs. 56%, p < 0.01) after the policy change, had significantly lower waitlist mortality (25% vs. 13%, p < 0.01) and fewer converted to a durable support (13% vs. 3%). The translatability (likelihood for receiving organs faster) was significantly improved after the policy change. A multivariable Cox regression model showed that post-transplant survival of Impella patients was not adversely affected after the policy change (hazard ratio = 0.9; p = 0.8). This increase in Impella use represents a substantial change in practice patterns of listing and managing patients on the heart transplant waiting list.

Patient selection for heart transplant: balancing risk

PURPOSE OF REVIEW

Heart failure incidence continues to rise despite a relatively static number of available donor hearts. Selecting an appropriate heart transplant candidate requires evaluation of numerous factors to balance patient benefit while maximizing the utility of scarce donor hearts. Recent research has provided new insights into refining recipient risk assessment, providing additional tools to further define and balance risk when considering heart transplantation.

RECENT FINDINGS

Recent publications have developed models to assist in risk stratifying potential heart transplant recipients based on cardiac and noncardiac factors. These studies provide additional tools to assist clinicians in balancing individual risk and benefit of heart transplantation in the context of a limited donor organ supply.

SUMMARY

The primary goal of heart transplantation is to improve survival and maximize quality of life. To meet this goal, a careful assessment of patient-specific risks is essential. The optimal approach to patient selection relies on integrating recent prognostication models with a multifactorial assessment of established clinical characteristics, comorbidities and psychosocial factors.

Device profile of the Impella 5.0 and 5.5 system for mechanical circulatory support for patients with cardiogenic shock: overview of its safety and efficacy

INTRODUCTION

Trans-valvular micro-axial flow pumps such as Impella are increasingly utilized in patients with cardiogenic shock [CS]. A number of different Impella devices are now available providing a wide range of cardiac output. Among these, the Impella 5.0 and recently introduced Impella 5.5 pumps can provides 5.55 L/min of flow, enabling complete left ventricular support with more favorable hemodynamic effects on myocardial oxygen consumption and left ventricular unloading. These devices require placement of a surgical conduit graft for endovascular delivery, but are increasingly being used in patients with CS due to acutely decompensated heart failure [ADHF], acute myocardial infarction [AMI] and after cardiac surgery as a bridge to transplant or durable ventricular assist device surgery or myocardial recovery.

AREAS COVERED

This review focuses on the device profile and use of the Impella 5.0 and 5.5 systems in patients with CS. Specifically; we reviewed the published literature for Impella 5.0 device to summarize data regarding safety and efficacy.

EXPERT OPINION

The Impella 5.0 and 5.5 are trans-valvular micro-axial flow pumps for which the current data suggest excellent safety and efficacy profiles as approaches to provide circulatory support, myocardial unloading, and axillary placement enabling patient mobilization and rehabilitation.

ABBREVIATIONS

pMCS, Percutaneous mechanical circulatory support devices; CS, Cardiogenic shock; ADHF, Acute decompensated heart failure; AMI, Acute myocardial infarction; LVAD, Left ventricular assist deviceI; ABP, Intra-aortic balloon pump; VA-ECLS, Veno-arterial extracorporeal life support.

Left Ventricular Unloading during Extracorporeal Life Support: Current Practice

Veno-arterial extracorporeal life support (VA-ECLS) is a powerful tool that can provide complete cardiopulmonary support for patients with refractory cardiogenic shock. However, VA-ECLS increases left ventricular afterload resulting in greater myocardial oxygen demand, which can impair myocardial recovery and worsen pulmonary edema. These complications can be ameliorated by various LV venting strategies to unload the LV. Evidence suggests that LV venting improves outcomes in VA-ECLS, but there is a paucity of randomized trials to help guide optimal strategy and the timing of venting. In this review, we discuss the available evidence regarding LV venting in VA-ECLS, explain important hemodynamic principles involved, and propose a practical approach to LV venting in VA-ECLS.

A case series analysis on the clinical experience of Impella 5.5® at a large tertiary care centre

Aims

We aimed to detail the early clinical experience with pVAD 5.5 at a large academic medical centre. Impella® 5.5 (Abiomed) is a temporary peripherally inserted left ventricular assist device (pVAD) used for the treatment of cardiogenic shock (CS). This system has several modifications aimed at improving deliverability and durability over the pVAD 5.0 system, but real‐world experience with this device remains limited.

Methods and results

We collected clinical and outcome data on all patients supported with pVAD 5.5 at our centre between February and December 2020, including procedural and device‐related complications. Fourteen patients with pVAD 5.5 were included. Aetiology of CS was acute myocardial infarction (n = 6), decompensated heart failure (n = 6), suspected myocarditis (n = 1), and post‐cardiotomy CS (n = 1). Four patients received pVAD 5.5 after being on inotropes alone, two were escalated from intra‐aortic balloon pump, two were escalated from pVAD CP, and six patients were transitioned to pVAD 5.5 from extracorporeal membrane oxygenation. Median duration of pVAD 5.5 support was 12 (interquartile range 7, 25) days. Complications included axillary insertion site haematoma (n = 3), acute kidney injury (n = 3), severe thrombocytopenia (n = 1), and stroke (n = 1). No valve injury or limb complications occurred. Survival to device explant for recovery or transition to another therapy was 11/14 (79%) patients.

Conclusions

In this early experience of the pVAD 5.5, procedural and device‐related complications were observed but were manageable, and overall survival was high in this critically ill cohort, particularly when the device was used as a bridge to other therapies.

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

OBJECTIVE

To report the initial clinical experience with the Impella 5.5^® with SmartAssist^®, a temporary left ventricular assist device that provides up to 6.2 L/min forward flow, with recent FDA approval for up to 14 days.

METHODS

From October 2019 to March 2020, 200 patients at 42 US centers received the Impella 5.5 and entered into the IQ registry, a manufacturer-maintained quality database that captures limited baseline/procedural characteristics and outcomes through device explant. Post hoc subgroup analyses were conducted to assess the role of baseline and procedural characteristics on survival, defined as successful device weaning or bridge to durable therapy.

RESULTS

Median patient age was 62 years (range, 13 to 83 years); 83.4% were male. The device was most commonly used for cardiomyopathy (45.0%), acute myocardial infarction complicated by cardiogenic shock (AMICS; 29.0%), and post cardiotomy cardiogenic shock (PCCS; 16.5%). Median duration of support was 10.0 days (range, 0.001 to 64.4 days). Through device explant, overall survival was 74.0%, with survival of 80.0%, 67.2%, 57.6%, and 94.7% in cardiomyopathy, AMICS, PCCS, and others (comprising high-risk revascularization, coronary artery bypass graft, electrophysiology/ablation, and myocarditis), respectively. Patients requiring extracorporeal membrane oxygenation and Impella support (35 patients, 17.5%) had significantly lower survival (51.4% vs 78.8%, P = 0.002).

CONCLUSIONS

In the first 200 US patients treated with the Impella 5.5, we observed overall survival to explant of 74%. Survival outcomes were improved compared to historic rates observed with cardiogenic shock, particularly PCCS. Prospective studies assessing comparative performance of this device to conventional strategies are warranted in future.

Temporary Mechanical Circulatory Support as a Bridge to Heart Transplant or Durable Left Ventricular Assist Device

Advanced heart failure refractory to medical therapy can result in patients presenting with progressively worsening hypoperfusion and cardiogenic shock. Temporary mechanical circulatory support is often necessary as a bridge to heart transplant or durable ventricular assist devices. These devices increase cardiac output. Several options are available for left ventricular support. With the exception of venoarterial extracorporeal membrane oxygenation, all other devices decrease left ventricular end-diastolic pressure. The choice of device should be driven by patient needs and the treating teams comfort. Timely identification of cardiogenic shock and use of shock teams are potential strategies that can help improve survival.

Budget Impact Associated with the Introduction of the Impella 5.0® Mechanical Circulatory Support Device for Cardiogenic Shock in France

AIM

Cardiogenic shock (CS), if not diagnosed and treated rapidly, can lead to irreversible multiorgan damage and death. An economic analysis was conducted to determine the budget impact of the introduction of Impella 5.0®, a mechanical circulatory support (MCS) device that directly unloads the left ventricle, into clinical practice in patients with left ventricular CS in France.

METHODS

A budget impact model was developed to compare the cost of Impella 5.0 with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) from the perspective of the French national healthcare insurer. Costs associated with Impella 5.0, plus complication-related costs for VA-ECMO or Impella 5.0 from 2019 were included and clinical input data relating to complication rates and time spent on device were sourced from published literature. Extensive scenario and one-way deterministic sensitivity analyses were performed to explore the influence of uncertainty around key input parameters.

RESULTS

Over a time horizon of 5 years, the introduction of Impella 5.0 was associated with cumulative savings of EUR 4.3 million. The results were driven by the lower risk of device-related complications associated with Impella 5.0. Savings were apparent from Year 1 onwards, with savings in excess of EUR 375,000 projected in Year 1 alone. On a per-patient level, in Year 1, estimated savings with the introduction of Impella 5.0 totaled EUR 616 per patient. Sensitivity analyses showed that the findings of the analysis were robust.

CONCLUSION

The Impella 5.0 device was associated with cumulative cost savings in excess of EUR 4 million over a 5-year period compared with current practice. Projected savings were driven by a lower rate of device-related complications with Impella 5.0 compared with VA-ECMO.

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.

Outcomes of heart transplantation in patients bridged with Impella 5.0: Comparison with native chest transplanted patients without preoperative mechanical circulatory support

The Impella (Abiomed, Danvers, MA, USA) has become an important adjunct treatment modality in bridging patients with end-stage heart failure to recovery or orthotopic heart transplantation (HTx). We compared the outcome of patients directly bridged to HTx with the Impella 5.0 versus patients without mechanical circulatory support (MCS). Patients with no previous sternotomy or MCS, who were transplanted between September 2014 and March 2019 were included in this retrospective analysis. Impella 5.0 was implanted using surgical access and transesophageal echocardiography guidance. Forty-two out of 155 transplanted patients fulfilled the insertion criteria. Eight (19%) were bridged with Impella 5.0 to HTx. Recipient and donor baseline characteristics were comparable in both groups. There were no significant differences in survival between the groups at 30-day (94% no MCS vs. 87.5% Impella group, P = .47) or 6 months (94% vs. 87.5%, P = .51). Patients on Impella 5.0 showed a significant recovery of hemodynamic parameters and end-organ function. Average duration of support to HTx was 16 ± 17 days. Impella 5.0, when used in suitable patients in a timely fashion can be a good strategy for bridging patients to HTx. The axillary approach allows for early extubation and mobilization. Outcomes of patients bridged to HTx with Impella 5.0 in acute cardiogenic shock are comparable to those of patients with no MCS.