Heart transplant waiting list implications of increased ventricular assist device use as a bridge strategy: A national analysis.

The use of ventricular assist devices (VADs) as a bridge to heart transplant (HT) is increasing, while HT volume remains stagnant. This may portend longer waiting times and an otherwise more competitive environment for all patients on the HT waiting list. A retrospective analysis of patients who were listed for HT in the United Network for Organ Sharing (UNOS) database from 2000 to 2015 was conducted. Mean waiting time, proportion of HT reception (%HT), proportion of death (%death), and proportion of waiting list removal (%removal) were calculated across three eras: Era 1 (2000-2007), Era 2 (2008-2011), and Era 3 (2012-2015). During the study period, 29 728 patients successfully underwent HT. 19 127 (64.3%) were directly transplanted (direct HT); 4491 (15.1%) received VADs prior to listing as a bridge to decision (BTD); and 4593 (15.5%) received VADs after listing as a bridge to transplant (BTT). Across the three eras, the average number of registrants per year grew. Among all groups, waiting time increased across the eras. %HT generally decreased in the BTD and BTT groups but remained constant in the direct HT group. %removal increased, while %death decreased in all group across the eras. Waiting time for HT increased from 2000 to 2015. Patients with VADs as a bridge strategy experienced decreasing %HT and increasing %removal but stable survival. Improvements in VAD safety and durability will ensure their success as part of a bridge strategy to HT under the new UNOS allocation policy.

A Novel Extracorporeal Continuous-Flow Ventricular Assist System for Patients With Advanced Heart Failure　- Initial Clinical Experience.

BACKGROUND: Bridge-to-decision (BTD) devices providing temporary mechanical circulatory support should be introduced to patients with advanced heart failure. This study evaluated the effectiveness and safety of a BTD device comprising an innovative extracorporeal continuous-flow temporary ventricular assist device (VAD) driven by a novel hydrodynamically levitated centrifugal flow blood pump.Methods and Results:Nine patients, comprising 3 with dilated cardiomyopathy, 3 with fulminant myocarditis, and 3 with ischemic heart disease, and 6 males, whose mean age was 47.7±8.1 years, were enrolled into the study. Six patients had Interagency Registry for Mechanically Assisted Circulatory Support profile 1, and 3 were profile 2. The primary endpoint was a composite of survival free from device-related serious adverse events and complications during circulatory support. Eight patients received left ventricular support, of whom 3 received concomitant right ventricular support using extracorporeal membrane oxygenation circuits, as a consequence of severe respiratory failure. One patient with fulminant myocarditis received biventricular support using the novel VAD system. After 19.0±13.5 days, 3 patients were weaned from circulatory support, because their native cardiac function recovered, and 6 patients required conversion to a durable device as a bridge-to-transplantation. One patient had non-disabling ischemic stroke episodes, and no patients died. CONCLUSIONS: This novel extracorporeal VAD system with a hydrodynamically levitated centrifugal pump can safely and successfully bridge patients with advanced heart failure to subsequent therapeutic stages.

Miniaturized centrifugal ventricular assist device for bridge to decision: Preclinical chronic study in a bovine model.

We developed a novel miniaturized extracorporeal centrifugal pump "BIOFLOAT NCVC (Nipro Corporation Osaka, Japan) as a ventricular assist device (VAD) and performed a preclinical study that is part of the process for its approval as a bridge to decision by the pharmaceutical and medical device agencies. The aim of this study was to assess the postoperative performance, hemocompatibility, and anticoagulative status during an extended period of its use. A VAD system, consisting of a hydrodynamically levitated pump, measuring 64 mm by 131 mm in size and weighing 635 g, was used. We installed this assist system in 9 adult calves (body weight, 90 ± 13 kg): as left ventricular assist device (LVAD) in 6 calves and right ventricular assist device (RVAD) in 3 calves, for over 30 days. Perioperative hemodynamic, hematologic, and blood chemistry measurements were obtained and end-organ effects on necropsy were investigated. All calves survived for over 30 days, with a good general condition. The blood pump was operated at a mean rotational speed and a mean pump flow of 3482 ± 192 rpm and 4.08 ± 0.15 L/min, respectively, for the LVAD and 3902 ± 210 rpm and 4.24 ± 0.3 L/min, respectively, for the RVAD. Major adverse events, including neurological or respiratory complications, bleeding events, and infection were not observed. This novel VAD enabled a long-term support with consistent and satisfactory hemodynamic performance and hemocompatibility in the calf model. The hemodynamic performance, hemocompatibility, and anticoagulative status of this VAD system were reviewed.

Assessment of Safety and Effectiveness of the Extracorporeal Continuous-Flow Ventricular Assist Device (BR16010) Use as a Bridge-to-Decision Therapy for Severe Heart Failure or Refractory Cardiogenic Shock: Study Protocol for Single-Arm Non-randomized, Uncontrolled, and Investigator-Initiated Clinical Trial.

BACKGROUND: The management of heart failure patients presenting in a moribund state remains challenging, despite significant advances in the field of ventricular assist systems. Bridge to decision involves using temporary devices to stabilize the hemodynamic state of such patients while further assessment is performed and a decision can be made regarding patient management. The purpose of this study (NCVC-BTD_01, National Cerebral and Cardiovascular Center-Bridge to Dicision_01) is to assess the safety and effectiveness of the newly developed extracorporeal continuous-flow ventricular assist system employing a disposable centrifugal pump with a hydrodynamically levitated bearing (BR16010) use as a bridge-to-decision therapy for patients with severe heart failure or refractory cardiogenic shock. METHOD/DESIGN: NCVC-BTD_01 is a single-center, single-arm, open-label, exploratory, medical device, investigator-initiated clinical study. It is conducted at the National Cerebral and Cardiovascular Center in Japan. A total of nine patients will be enrolled in the study. The study was planned using Simon's minimax two-stage phase design. The primary endpoint is a composite of survival free of device-related serious adverse events and complications during device support. For left ventricular assistance, withdrawal of a trial device due to cardiac function recovery or exchange to other ventricular assist devices (VADs) for the purpose of bridge to transplantation (BTT) during 30 days after implantation will be considered study successes. For right ventricular assistance, withdrawal of tal device due to right ventricular function recovery within 30 days after implantation will be considered a study success. Secondary objectives include changes in brain natriuretic peptide levels (7 days after implantation of a trial device and the day of withdrawal of a trial device), period of mechanical ventricular support, changes in left ventricular ejection fraction (7 days after implantation of a trial device and the day of withdrawal of a trial device), and changes in left ventricular diastolic dimension (7 days after implantation of a trial device and the day of withdrawal of a trial device). ETHICS AND DISSEMINATION: We will disseminate the findings through regional, national, and international conferences and through peer-reviewed journals. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN-CTR; R000033243) registered on 8 September 2017.

Novel temporary left ventricular assist system with hydrodynamically levitated bearing pump for bridge to decision: initial preclinical assessment in a goat model.

The management of heart failure patients presenting in a moribund state remains challenging, despite significant advances in the field of ventricular assist systems. Bridge to decision involves using temporary devices to stabilize the hemodynamic state of such patients while further assessment is performed and a decision can be made regarding patient management. We developed a new temporary left ventricular assist system employing a disposable centrifugal pump with a hydrodynamically levitated bearing. We used three adult goats (body weight, 58-68 kg) to investigate the 30-day performance and hemocompatibility of the newly developed left ventricular assist system, which included the pump, inflow and outflow cannulas, the extracorporeal circuit, and connectors. Hemodynamic, hematologic, and blood chemistry measurements were investigated as well as end-organ effect on necropsy. All goats survived for 30 days in good general condition. The blood pump was operated at a rotational speed of 3000-4500 rpm and a mean pump flow of 3.2 ± 0.6 L min. Excess hemolysis, observed in one goat, was due to the inadequate increase in pump rotational speed in response to drainage insufficiency caused by continuous contact of the inflow cannula tip with the left ventricular septal wall in the early days after surgery. At necropsy, no thrombus was noted in the pump, and no damage caused by mechanical contact was found on the bearing. The newly developed temporary left ventricular assist system using a disposable centrifugal pump with hydrodynamic bearing demonstrated consistent and satisfactory hemodynamic performance and hemocompatibility in the goat model.

Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation as a Bridge to Decision for Pediatric Fulminant Myocarditis.

It is essential to establish an appropriate initial treatment strategy for pediatric fulminant myocarditis. We reviewed eight cases of pediatric fulminant myocarditis that required extracorporeal membrane oxygenation (ECMO) from 2012 to 2015. The median age was 8 years (range 3 months-13 years), and the median body surface area was 0.89 m(2) (range 0.35-1.34 m(2) ). Peripheral veno-arterial ECMO was initially applied, and we evaluated whether heart decompression was sufficient. If the pump flow was insufficient, central cannulation was performed via median sternotomy (central ECMO). The need for subsequent ventricular assist device (VAD) support was determined 72 h after ECMO initiation. Six patients were bridged to recovery using peripheral ECMO support only (for 3-11 days), whereas two required VAD support. One patient was switched to central ECMO before VAD implantation. Three patients died of multiorgan failure, even though cardiac function recovered in two of those patients. The duration from hospital arrival to ECMO initiation was shorter in the survival (3.3 ± 1.3 h; range 1.6-4.7 h) than in the nonsurvival group (32 ± 28 h; range 0.7-55 h). Peripheral ECMO can be useful as a bridge to decision for pediatric fulminant myocarditis, which is frequently followed by a successful bridge to recovery. It is important to determine whether ECMO support should be initiated before organ dysfunction advances to preserve organ function, which provides a better bridge to subsequent VAD therapy and heart transplant or recovery.

Comparison of Impella 5.0 and extracorporeal left ventricular assist device in patients with cardiogenic shock.

INTRODUCTION: Choice of mechanical circulatory support to stabilize hemodynamics until cardiac recovery or next treatment is a strategic cornerstone for improving outcomes in patients with severe cardiogenic shock. We aimed to clarify the difference in treatment course and outcomes with the use of Impella 5.0 and an extracorporeal left ventricular assist device (eLVAD) in patients with cardiogenic shock refractory to medical therapy or other mechanical circulatory support. METHODS: We performed a retrospective medical record review of consecutive patients who were implanted with Impella 5.0 or eLVAD as a bridge to decision at our medical center. RESULTS: A total of 26 patients (median age 40 years, 16 males) were analyzed. Of seven patients managed with Impella 5.0, the Impella 5.0 was removed successfully in two patients and five patients underwent surgery for durable LVAD implantation. Of 19 patients managed with eLVAD, the eLVAD was successfully removed in 3 patients, 9 patients required durable LVAD, and 7 patients died during eLVAD management. The period between Impella 5.0 or eLVAD implantation to durable LVAD surgery was significantly shorter with Impella 5.0 (58 vs 235 days, p = 0.001). Cardiopulmonary bypass time was significantly shorter and a significantly smaller amount of red blood cell transfusion was required with Impella 5.0 (149 vs 192 min, p = 0.042; 7.0 vs 15.0 units, p = 0.019). There were four massive stroke events with eLVAD, but no massive stroke event with Impella 5.0. CONCLUSION: Impella 5.0 facilitates smoother management as a bridge to decision and reduces surgical invasiveness during durable LVAD implantation.

Current indication and practical management of percutaneous left ventricular assist device support therapy in Japan.

Impella (Abiomed, Danvers, MA, USA) is a recently-innovated (commercially available from 2017 in Japan) percutaneous left ventricular assist device which is inserted percutaneously and transfers blood from the left ventricle to the ascending aorta, improving systemic circulation and end-organ dysfunction as well as unloading left ventricle in patients with cardiogenic shock. Impella has not yet shown a significant survival benefit in patients with cardiogenic shock compared to intra-aortic balloon pump in randomized control trials, but gives powerful circulatory support immediately with minimally invasive manner when used in appropriate patients at optimal timing with adequate management. In this review article, we will introduce and discuss optimal and practical management of Impella therapy in Japan.

Temporary ventricular assist device implantation by sternotomy-avoiding technique for bridge-to-decision therapy: a comparison with conventional implantation.

OBJECTIVE: Temporary ventricular assist device (VAD) is a commonly used therapeutic option for cardiogenic shock. Patients requiring this treatment are often critical, and clinical outcomes remain unsatisfactory. This study evaluated the feasibility and efficacy of a sternotomy-avoiding technique for temporary VAD implantation to improve patient outcomes. METHODS: Between December 2012 and November 2018, seven patients underwent temporary VAD implantation by sternotomy-avoiding technique (SA group) and eight by median sternotomy technique (MS group). Pre- and intraoperative characteristics, postoperative 7-day hemodynamic parameters, 30-day mortality, and adverse events were compared between the groups. RESULTS: More than 50% of the patients were mechanically supported before temporary VAD implantation. Cardiopulmonary bypass time was significantly shorter in the SA than in the MS group (84 min vs 215 min; p = 0.011); surgical time tended to be shorter in the SA group (385 min vs 461 min; p = 0.064). Pump index, cardiac index, mixed venous oxygen saturation, and central venous pressure did not differ significantly during the first seven days of support. The 30-day incidence of any adverse event was not significantly different between the groups. No patients in the SA group needed re-exploration for surgical bleeding. Thirty-day all-cause mortality rates were 29% in the SA group and 0% in the MS group (p = 0.11). CONCLUSIONS: The sternotomy-avoiding and conventional techniques resulted in comparable short-term hemodynamic support. The sternotomy-avoiding technique was associated with a potential reduction in risk of re-exploration for bleeding. These results support the usefulness of the sternotomy-avoiding procedure for selected patients.

Outcome of CentriMag™ extracorporeal mechanical circulatory support use in critical cardiogenic shock (INTERMACS 1) patients.

Purpose: Prognosis of patients presenting with INTERMACS 1 critical cardiogenic shock is generally poor. The aim of our study was to investigate the results of CentriMag™ extracorporeal short-term mechanical circulatory support as a bridge to decision in patients presenting with critical cardiogenic shock in our unit. Methods: We retrospectively analysed 63 consecutive patients from January 2005 to June 2017, who were treated with a CentriMag™ device at our institution as a bridge to decision. Patients requiring extracorporeal support for post-cardiotomy shock and for primary graft dysfunction after heart transplantation were excluded. Results: Patients' median age was 44 years (IQR 31-52, range 15.4-62.0) and 42 (67%) were male. Primary diagnosis at presentation was ischaemic cardiomyopathy (n = 24; 38.1%), viral myocarditis (n = 19; 30.2%), idiopathic dilated cardiomyopathy (n = 8; 12.7%), and others (n = 12; 19%). The median duration of support was 25 (IQR 9.5-56) days. A total of 7 (11%) patients were supported with peripheral veno-arterial (VA) extra corporeal membrane oxygenation (ECMO), 6 (9%) with central VA ECMO, 8 (13%) with left ventricular assist device (LVAD), 17 (27%) with biventricular assist device (BiVAD), and 25 (40%) with ECMO and then converted to BiVAD. Overall, 22 (34.9%) patients died while on CentriMag™ mechanical circulatory support. Complications included bleeding requiring reoperation/intervention in 24 (38%), renal failure requiring dialysis in 29 (46%), bacterial infections in 23 (37%), fungal infections in 15 (24%), critical limb ischaemia in 6 (10%), and stroke in 8 (13%). The overall survival to successful explant from CentriMag™ was 65.1% (n = 41) and survival to hospital discharge was 58.7% (n = 37). Of these, 10 (16%) had cardiac recovery and were successfully explanted, 20 (32%) were bridged to heart transplantation, 11 (17%) were bridged to long-term left ventricular assist device, 3 (4.7%) were later on transplanted, and 1 (1.6%) recovered to decommissioning. The 1-, 5-, and 10-year survival rates were 55%, 46%, and 23% respectively. Conclusion: Our results demonstrate an excellent outcome with the use of the CentriMag™ device in this seriously ill population. Despite requiring multiple procedures, over 58% of patients were discharged from hospital with 5-year survival of 46%.

Percutaneous temporary circulatory support devices and their use as a bridge to decision during acute decompensation of advanced heart failure.

Temporary mechanical cardiac support (TMCS) devices intend to restore systemic perfusion and prevent further end-organ damage in patients with refractory cardiogenic shock until the insult is addressed. TMCS has been associated with reductions in hospital costs and in-hospital mortality. We review the four primary TMCS modalities available: intra-aortic balloon pump, TandemHeart, veno-arterial extracorporeal membrane oxygenation, and Impella pump. All have their own implantation technique and hemodynamic profile, and their use may therefore be tailored to the specific patient's needs. The appropriate TMCS may thus help stabilize the patient, enabling the care team to make decisions about durable support or transplantation.

Use of a percutaneous temporary circulatory support device as a bridge to decision during acute decompensation of advanced heart failure.

BACKGROUND: Prognosis is poor for patients with decompensated advanced heart failure (HF) refractory to medical therapy. Evaluating candidacy for durable mechanical circulatory support (MCS), cardiac transplantation, or palliative care is complex, and time is often needed to stabilize the patient hemodynamically. The Impella 5.0 (Abiomed, Danvers, MA) is a minimally invasive axial-flow catheter capable of providing full temporary hemodynamic support. We report a multicenter series on the use of this device for bridge to decision (BTD) in decompensated advanced HF patients. METHODS: In a retrospective evaluation at 3 centers of patients with advanced HF who acutely decompensated and received the Impella 5.0 for BTD, we analyzed demographics, procedural characteristics, in-hospital and intermediate-term outcomes, and in-hospital complications. RESULTS: There were 58 patients who met inclusion criteria from 2010 to 2015. All were inotrope dependent. The mean ejection fraction was 13%, and median age was 59 years (interquartile range, 48-64 years). Mean duration of support was 7 days (range, 0-22 days). Thirty-nine patients survived to next therapy (67%), with most receiving durable MCS (n = 20) or heart transplantation (n = 15). In-hospital complications included bleeding (n = 9) and hemolysis (n = 4). Of patients who survived to the next therapy, 1-year survival was 65% for those who received durable MCS, 87% for those who received a transplant, and 75% for those who were stabilized and weaned. CONCLUSIONS: The Impella 5.0 may provide a BTD strategy for patients with advanced HF and acute hemodynamic instability. Prospective studies are needed to evaluate the safety and effectiveness of this device in this patient population.

Contemporary mechanical circulatory support therapy for postcardiotomy shock.

Significant progress has been made in the use of mechanical circulatory support (MCS), particularly in the clinical success in durable left ventricular assist device. Short-term MCS has also advanced in the form of venoarterial extracorporeal membrane oxygenation, external centrifugal VADs as well as percutaneous VADs. Postcardiotomy shock (PCS) is a rare clinical entity associated with substantial morbidity and mortality. It is characterized by heart failure that either results in an inability to wean from cardiopulmonary bypass or that occurs in the immediate postoperative period, accounting for the most common indication for MCS. The reported in-hospital mortality of the PCS patients remains high, consistently over 50%, despite ongoing refinements of MCS technology. The optimization of selection criteria and the prompt institution of MCS are likely the keys to improving this persistently high mortality rate. Unfortunately, the lack of a clear definition for PCS in the literature limits scientific analyses and comparison of the existing evidence. To establish the treatment strategy and appropriately manage this challenging disease, substantial and fundamental effort by the cardiovascular society is imperative.