Impella RP as a bridge to cardiac transplant for refractory late right ventricular failure in setting of left ventricular assist device

Waitlist and transplant outcomes in heart transplant candidates bridged with temporary endovascular right ventricular assist devices

BACKGROUND

Advances in mechanical circulatory support and changes in allocation policy have shifted waitlisting practices for heart transplantation (HT) in the United States. This analysis reports waitlist and transplant outcomes among HT candidates bridged with temporary endovascular right ventricular assist devices (tRVADs).

METHODS

Patients awaiting HT from 2008 to 2022 in the United Network of Organ Sharing registry were grouped by the presence of tRVAD while waitlisted and propensity matched. Waitlist outcomes were HT and a competing outcome of death/deterioration requiring waitlist inactivation. Competing-risks regression was used to model waitlist outcomes. Subanalyses were performed to compare waitlist outcomes among patients with durable and temporary left ventricular assist devices (LVADs) with and without concomitant tRVADs. One-year posttransplant mortality was estimated using Kaplan-Meier analysis.

RESULTS

Of 41,507 HT candidates, 133 (0.3%) had tRVADs. After propensity matching, patients with tRVAD had a similar likelihood of HT and an elevated hazard for death/deterioration (hazard ratio 2.2, 95% confidence interval 1.4-3.2, p < 0.001) compared to those without tRVAD. Most patients with tRVAD (84%) had concomitant LVADs. tRVAD was associated with an elevated risk for deterioration/death among those with temporary LVADs but not durable LVADs. For patients undergoing HT, tRVAD was associated with an increased risk for 1-year mortality compared to propensity-matched recipients.

CONCLUSIONS

Bridging with tRVAD is uncommon and primarily used in patients requiring biventricular support. tRVADs are associated with waitlist inactivation or death, particularly with concomitant temporary LVAD support. As temporary devices are increasingly used as a bridge to HT, outcomes of patients with tRVADs should inform future allocation policy, particularly for candidates with biventricular failure.

Successful echocardiography-guided medical management of severe early post-implant right ventricular failure in a patient with left ventricular assist device support: a case report

BACKGROUND

Post-implant right heart failure (RHF) has been recognized as a crucial prognostic factor in patients receiving left ventricular assist devices (LVADs), and its management has long attracted attention from cardiologists and surgeons.

CASE PRESENTATION

This report described an 18-year-old female with acutely deteriorating heart failure due to dilated cardiomyopathy who underwent paracorporeal pulsatile-flow LVAD and developed early post-implant RHF. At postoperative day (POD) six, she was almost asymptomatic at rest on 2.5 mg/kg/min of dobutamine; however, the echocardiogram, performed as part of the daily postoperative care, revealed a severely enlarged right ventricle with a decompressed left ventricle, implying the development of post-implant RHF. Bolus infusion of saline and reduction of pump flow (6.0 L/min to 3.0 L/min) led to normalization of both ventricular shapes in 30 s, suggesting that RHF could be managed without surgical interventions. Milrinone was started on POD six, followed by sildenafil administration on POD seven. Fluid balance was strictly adjusted under the close observation of daily echocardiograms. Milrinone and dobutamine were discontinued on PODs 18 and 21, respectively. The patient was listed for a heart transplant on POD 40. Despite reduced right ventricular function (right ventricular stroke work index of 182.34 mmHg*ml/m- 2, body surface area 1.5 m2), she was successfully converted to implantable LVAD on POD 44 with no recurrence of post-implant RHF thereafter for four years.

CONCLUSIONS

In post-implant RHF management, early detection, together with proper and prompt medical management, is crucial to avoiding any surgical intervention. Close observation of daily echocardiograms might be helpful in detecting subclinical RHF and is useful for post-implant medical management.

Temporary Right Ventricular Assist Device Support for Acute Right Heart Failure: A Single-Center Experience

INTRODUCTION

Severe right ventricular (RV) failure is associated with significant morbidity and mortality. Although right ventricular assist devices (RVADs) are increasingly used for refractory RV failure, there is limited data on their short- and long-term outcomes. Therefore, we undertook this study to better understand our experience with temporary RVADs.

METHODS

We conducted a retrospective review of all RVADS performed from 2017 to 2021. Patients supported with surgical RVADs, the Protek Duo device, and the Impella RP device were included. Patients were stratified by the type of RVAD and by etiology of RV failure. Survival was assessed by the Kaplan-Meier method and multivariable Cox proportional hazards regression models.

RESULTS

From 2017 to 2021, 42 patients underwent RVAD implantation: 32 with a Protek Duo, 6 with an Impella RP, and 4 with a surgical RVAD. Majority of patients were already supported with an alternate form of mechanical support. Most patients had impaired renal function, decreased hepatic function, and lactic acidosis at the time of cannulation. The median duration of RVAD support was 8.5 [5-19] d. Survival to decannulation was 68.4%, to discharge was 47.4%, and to 1-y was 40.2%. Multivariable analysis identified elevated total bilirubin levels to be associated with 30-d mortality while increased hemoglobin levels were protective. After RVAD cannulation, the median number of pressors and inotropes was lower (P < 0.01) and the lactic acidosis was less (P < 0.01).

CONCLUSIONS

In conclusion, RVAD support is associated with lower lactate levels, and decreased number of vasoactive medications, but is associated with significant morbidity and mortality.

Right-Sided Mechanical Circulatory Support - A Hemodynamic Perspective

PURPOSE OF REVIEW

Right ventricular (RV) failure is increasingly recognized as a major cause of morbidity and mortality. When RV failure is refractory to medical therapy, escalation to right-sided mechanical circulatory support (MCS) should be considered. In this review, we begin by recapitulating the hemodynamics of RV failure, then we delve into current and future right-sided MCS devices and describe their hemodynamic profiles.

RECENT FINDINGS

The field of temporary right-sided MCS continues to expand, with evolving strategies and new devices actively under development. All right-sided MCS devices bypass the RV, with each bypass configuration conferring a unique hemodynamic profile. Devices that aspirate blood directly from the RV, as opposed to the RA or the IVC, have more favorable hemodynamics and more effective RV unloading. There has been a growing interest in single-access MCS devices which do not restrict patient mobility. Additionally, a first-of-its-kind percutaneous, pulsatile, right-sided MCS device (PERKAT RV) is currently undergoing investigation in humans. Prompt recognition of refractory RV failure and deployment of right-sided MCS can improve outcomes. The field of right-sided MCS is rapidly evolving, with ongoing efforts dedicated towards developing novel temporary devices that are single access, allow for patient mobility, and directly unload the RV, as well as more durable devices.

First-in-man successful use of the SPECTRUM percutaneous dual-stage right ventricle and right atrium to pulmonary artery ventricular assist device

BACKGROUND

Over the past decade, several minimally invasive mechanical support devices have been introduced into clinical practice to support the right ventricle (RV). Percutaneous cannulas are easy to insert, minimally invasive, and treat acute RV failure rapidly. In December 2021, the Food and Drug Administration approved a new 31 French dual lumen single cannula for use as a right ventricular assist device.

AIMS

Descirbe the use of the new dual lumen percutaneous right ventricular assist device (RVAD) cannula.

MATERIAL AND METHODS

Deployment of the RVAD can be done surgically or percutaneously. This cannula, manufactured by Spectrum, is dual staged. It has inflow ports positioned both in the right atrium (RA) as well as the RV for maximal drainage of the right heart. The distal end of the cannula which includes the outflow port is positioned in the pulmonary artery (PA).

RESULTS

Deployment of the Spectrum RVAD can be done percutaneously with transesophageal and flouroscopy guidence. Cannulation requires requisite wire skills in order to navigate into the main pulmonary artery. Utilization of this cannula can be done in acute RV failure secondary to ischemia, post cardiotomy shock, acute respiratory failure or other causes of isolated RV failure.

DISCUSSION

The dual stage drainage design optimizes venous drainage as well as limits suck-down events. Theoretically, direct RV decompression also decreases RV dilation and wall tension, and facilitates improved transmural pressure gradient to reduce RV strain.

CONCLUSION

Here we describe the first-in-man successful use of the dual-stage RA and RV to PA Spectrum cannula in a patient with severe COVID acute respiratory distress syndrome and acute right ventricular failure, bridged to recovery.

Impella RP for Patients with Acute Right Ventricular Failure and Cardiogenic Shock: A Subanalysis from the IMP-IT Registry

The use of percutaneous right ventricular assist devices (pRVADs) to support patients with right ventricular (RV)-predominant cardiogenic shock (CS) refractory to optimal medical therapy is increasing progressively, and the Impella RP is the first FDA-approved pRVAD in such a clinical scenario. The aim of the present study is to report the outcomes of patients treated with Impella RP in the IMP-IT (IMPella Mechanical Circulatory Support Device in Italy) registry, a multicenter registry that evaluated the trends in use and clinical outcomes of the Impella in the setting of CS and high-risk percutaneous coronary intervention in Italy. A total of 15 patients who received Impella RP were enrolled. In 40% of the patients, the main cause was ST-segment elevation myocardial infarction. A total of 40% of patients required biventricular support with a left Impella. Device-related complications were reported in 46.7% of patients. Overall, the in-hospital mortality was 46.7%, whereas the one-year mortality was 53.3%. The composite rate of all-cause death, heart failure (HF) hospitalization, left ventricular assist device (LVAD) and heart transplant at one year was 60%. The Impella RP has favorable survival outcomes in RV-predominant cardiogenic shock. However, the device-related complications are frequent and should be carefully weighed when considering escalation to Impella RP.

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.

Bridge to transplantation from mechanical circulatory support: a narrative review

Objective

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

Background

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

Methods

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

Conclusions

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

The use of mechanical assist devices in the pediatric population

The last two decades have witnessed an expansion in the devices, support strategies, and outcomes for pediatric patients who require mechanical circulatory support. The use of large registries that house data on these devices and the development of shared learning networks have provided clinicians with the ability to critically assess outcomes for emerging and existing technology. The purpose of this review is to provide the reader with perspective on the most contemporary devices utilized for pediatric mechanical circulatory support. It will examine existing support strategies and the most contemporary outcomes regarding these devices including those in high risk patients.

Impella RP as a bridge to cardiac transplant for refractory late right ventricular failure in setting of left ventricular assist device

Right ventricular (RV) failure remains a major complication after surgical implantation of a left ventricular assist device (LVAD). While the use of a percutaneous RV assist device has been described as a short‐term bridge to recovery in end‐stage heart failure patients with early post‐operative RV failure after index LVAD implant, management of refractory late RV failure remains challenging in these patients. We report the first successful case of extended Impella RP use as a safe and effective bridge to orthotopic heart transplant in an LVAD patient with refractory, haemodynamically significant late RV failure. The Impella RP provided support for 37 days. Haemodynamically intolerant arrhythmia precluded use of inotropic support. No adverse complications related to percutaneous Impella RP support were seen. We also review potential considerations for mechanical circulatory support strategies in this setting: central RV assist device cannulation requires sternotomy incision that can impact subsequent cardiac surgeries, while percutaneous Protek Duo insertion requires adequate vessel size and patency. With an LVAD in situ, veno‐arterial extracorporeal membrane oxygenation was not considered for isolated RV support in this case. The patient is currently over 6 months post‐orthotopic heart transplant.