Clinical Performance with the Levitronix Centrimag Short-term Ventricular Assist Device

Use of a surgically implanted, nondischargeable, extracorporeal continuous flow circulatory support system as a bridge to heart transplant

INTRODUCTION AND OBJECTIVES

We aimed to describe the clinical outcomes of the use of the CentriMag acute circulatory support system as a bridge to emergency heart transplantation (HTx).

METHODS

We conducted a descriptive analysis of the clinical outcomes of consecutive HTx candidates included in a multicenter retrospective registry who were treated with the CentriMag device, configured either for left ventricular support (LVS) or biventricular support (BVS). All patients were listed for high-priority HTx. The study assessed the period 2010 to 2020 and involved 16 transplant centers around Spain. We excluded patients treated with isolated right ventricular support or venoarterial extracorporeal membrane oxygenation without LVS. The primary endpoint was 1-year post-HTx survival.

RESULTS

The study population comprised 213 emergency HTx candidates bridged on CentriMag LVS and 145 on CentriMag BVS. Overall, 303 (84.6%) patients received a transplant and 53 (14.8%) died without having an organ donor during the index hospitalization. Median time on the device was 15 days, with 66 (18.6%) patients being supported for> 30 days. One-year posttransplant survival was 77.6%. Univariable and multivariable analyses showed no statistically significant differences in pre- or post-HTx survival in patients managed with BVS vs LVS. Patients managed with BVS had higher rates of bleeding, need for transfusion, hemolysis and renal failure than patients managed with LVS, while the latter group showed a higher incidence of ischemic stroke.

CONCLUSIONS

In a setting of candidate prioritization with short waiting list times, bridging to HTx with the CentriMag system was feasible and resulted in acceptable on-support and posttransplant outcomes.

Predicting outcomes following short-term ventricular assist device implant with the MELD-XI score

BACKGROUND

Short-term continuous flow (STCF) ventricular assist devices (VADs) are utilized in adults with cardiogenic shock; however, mortality remains high. Previous studies have found that high pre-operative MELD-XI scores in durable VAD patients are associated with mortality. The use of the MELD-XI score to predict outcomes in STCF-VAD patients has not been explored. We sought to determine the relationship between MELD-XI and outcomes in adults with STCF-VADs.

METHODS

This was a retrospective review of adults implanted with STCF-VADs between 2009 and 2019. Receiver operating characteristic (ROC) analysis was performed to predict outcomes and Kaplan-Meier analysis was done to assess survival.

RESULTS

Seventy-nine patients were included with a median MELD-XI score of 21.2 (IQR 13.5, 27.0). Patients with an unsuccessful wean from support (p < 0.001) or major post-operative bleeding (p = 0.03) had significantly higher pre-implant MELD-XI scores. The optimal MELD-XI cut-point for mortality was 24.9 with 27.8 for major bleeding. Survival was worse among patients in the high-risk MELD-XI group, however, not statistically significant (p = 0.09). Prior ECMO support, but not MELD-XI, was an independent predictor of unsuccessful wean (p = 0.03).

CONCLUSIONS

Pre-operative MELD-XI score was a moderate predictor of unsuccessful wean with limited utility in predicting bleeding in patients on STCF-VAD support. This scoring system may be useful in the clinical setting for pre-implant risk stratification and counseling among patients and outcomes.

Research progress of portable extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is primarily used for the supportive treatment of patients suffering from severe cardiopulmonary failure. With the continued development of ECMO technology, the relevant scenarios also extend pre-hospital and inter-hospital. In order to meet the needs of emergency treatment in communities, disaster sites and battlefields, inter-hospital transfer and evacuation; miniaturized and portable ECMO has become a current research hotspot.

AREA COVERED

The paper first introduces the principle, composition and common modes of ECMO and summarizes the research status of portable ECMO, Novalung and wearable ECMO, analyzes the characteristics and shortcomings of existing equipment. finally, we discussed the focus and development trend of portable ECMO technology.

EXPERT OPINION

Currently, portable ECMO has many applications in interhospital transport and there are various studies on portable and wearable ECMO devices, but the development of portable ECMO still faces many challenges. In the future, research related to integrated components, rich sensor arrays, Intelligent ECMO system and lightweight technology can make future portable ECMO more suitable for pre-hospital emergency and interhospital transport.

How to Optimize ECLS Results beyond Ventricular Unloading: From ECMO to CentriMag® eVAD

CentriMag^® extracorporeal VAD support could represent a more physiological choice than conventional ECMO in primary cardiogenic shock. We therefore evaluated the outcome of patients with primary cardiogenic shock who were supported with CentriMag^® extracorporeal VAD implantation versus conventional ECMO. We retrospectively reviewed all extracorporeal life supports implanted for primary cardiogenic shock between January 2009 and December 2018 at our institution. Among 212 patients, 143 cases (67%) were treated exclusively with ECMO (Group 1) and 69 cases (33%) with extracorporeal VAD implantation (Group 2, 48 of whom as conversion of ECMO). ECLS mean duration was 8.37 ± 8.43 days in Group 1 and 14.25 ± 10.84 days in Group 2 (p = 0.001), while the mean rates of the highest predicted flow were 61.21 ± 16.01% and 79.49 ± 18.42% (p = 0.001), respectively. Increasing mechanical support flow was related to in-hospital mortality and overall mortality in Group 1 (HR 11.36, CI 95%: 2.19–44.20), but not in Group 2 (HR 1.48, CI 95%: 0.32–6.80). High-flow ECMO patients had lower survival with respect to high-flow extracorporeal VAD patients (p = 0.027). In the setting of high-flow mechanical circulatory support, CentriMag^® extracorporeal VAD optimized patient survival, granting long-term assistance and physiological circulation patterns.

Extracorporeal Life Support and Temporary CentriMag Ventricular Assist Device to Salvage Cardiogenic-Shock Patients Suffering from Prolonged Cardiopulmonary Resuscitation

Background: The extracorporeal life support (ECLS) and temporary bilateral ventricular assist device (t-BiVAD) are commonly applied in patients with cardiogenic shock. Prolonged cardiopulmonary resuscitation (CPR) has poor prognosis. Herein, we report our findings on a combined ECLS and t-BiVAD approach to salvage cardiogenic-shock patients with CPR for more than one hour. Methods: Fifty-nine patients with prolonged CPR and rescued by ECLS and subsequent t-BiVAD were retrospectively collected between January 2015 and December 2019. Primary diagnoses included ischemic, dilated cardiomyopathy, acute myocardial infarction, post-cardiotomy syndrome, and fulminant myocarditis. The mean LVEF was 16.9% ± 6.56% before t-BiVAD. The median ECLS-to-VAD interval is 26 h. Results: A total of 26 patients (44%) survived to weaning, including 13 (22%) bridged to recovery, and 13 (22%) bridged to transplantation. Survivors to discharge demonstrated better systemic perfusion and hemodynamics than non-survivors. The CentriMag-related complications included bleeding (n = 22, 37.2%), thromboembolism (n = 5, 8.4%), and infection (n = 4, 6.7%). The risk factors of mortality included Glasgow Coma Scale (Motor + Eye) ≤ 5, and lactate ≥ 8 mmol/L at POD-1, persistent ventricular rhythm or asystole, and total bilirubin ≥ 6 mg/dL at POD-3. Mortality factors included septic shock (n = 11, 18.6%), central failure (n = 10, 16.9%), and multiple organ failure (n = 12, 20.3%). Conclusions: Combined ECLS and t-BiVAD could be a salvage treatment for patients with severe cardiogenic shock, especially for those already having prolonged CPR. This combination can correct organ malperfusion and allow sufficient time to bridge patients to recovery and heart transplantation, especially in Asia, where donation rates are low, as well as intracorporeal VAD or total artificial heart being seldom available.

Mechanical Circulatory Support for Right Ventricular Failure

Right ventricular (RV) failure is associated with significant morbidity and mortality, with in-hospital mortality rates estimated as high as 70–75%. RV failure may occur following cardiac surgery in conjunction with left ventricular failure, or may be isolated in certain circumstances, such as inferior MI with RV infarction, pulmonary embolism or following left ventricular assist device placement. Medical management includes volume optimisation and inotropic and vasopressor support, and a subset of patients may benefit from mechanical circulatory support for persistent RV failure. Increasingly, percutaneous and surgical mechanical support devices are being used for RV failure. Devices for isolated RV support include percutaneous options, such as micro-axial flow pumps and extracorporeal centrifugal flow RV assist devices, surgically implanted RV assist devices and veno-arterial extracorporeal membrane oxygenation. In this review, the authors discuss the indications, candidate selection, strategies and outcomes of mechanical circulatory support for RV failure.

A Comprehensive Review of Mechanical Circulatory Support Devices

Treatment strategies to combat cardiogenic shock (CS) have remained stagnant over the past decade. Mortality rates among patients who suffer CS after acute myocardial infarction (AMI) remain high at 50%. Mechanical circulatory support (MCS) devices have evolved as novel treatment strategies to restore systemic perfusion to allow cardiac recovery in the short term, or as durable support devices in refractory heart failure in the long term. Haemodynamic parameters derived from right heart catheterization assist in the selection of an appropriate MCS device and escalation of mechanical support where needed. Evidence favouring the use of one MCS device over another is scant. An intra-aortic balloon pump is the most commonly used short-term MCS device, despite providing only modest haemodynamic support. Impella CP® has been increasingly used for CS in recent times and remains an important focus of research for patients with AMI-CS. Among durable devices, Heartmate® 3 is the most widely used in the USA. Adequately powered randomized controlled trials are needed to compare these MCS devices and to guide the operator for their use in CS. This article provides a brief overview of the types of currently available MCS devices and the indications for their use.

Novel strategy for improved outcomes of extra-corporeal membrane oxygenation as a treatment for refractory post cardiotomy cardiogenic shock in the current era: a refreshing new perspective

OBJECTIVES

Post-cardiotomy cardiogenic shock is an infrequent but important cause of death following cardiac surgery. Extra-corporeal membrane oxygenation offers the opportunity for temporary cardiovascular support and myocardial rest, with a view to recovery. We examine our results with our recently-implemented management algorithm.

METHODS

We report our series of 15 consecutive patients out of 357 patients [4.2%] who required institution of veno-arterial extra-corporeal membrane oxygenation system support as treatment for Post-cardiotomy cardiogenic shock in the current era [January-2017 to January-2020].

RESULTS

The mean age was 64.3 ± 11.6 years (range: 40-82 years); there were 13 males (86.7%). Duration of veno-arterial extra-corporeal membrane oxygenation support was 6.7 ± 1.9 days. Duration of stay on intensive care unit [ICU] was 18.9 ± 17.1 days. Duration of hospital-stay was 28.3 ± 20.8 days. Survival to discharge and at 2.2 ± 0.9 years was 67%.

CONCLUSIONS

We have shown clearly that veno-arterial extra-corporeal membrane oxygenation is an important rescue option for patients who develop refractory post-cardiotomy cardiogenic shock, with improved survival of 67% at 2.2 ± 0.9 years in those placed on post-cardiotomy veno-arterial extra corporeal membrane oxygenation support, which is superior to that reported hitherto in literature. We have sought to highlight the successes of post cardiotomy veno-arterial extra corporeal membrane oxygenation support, with improved results, based on careful patient selection, as well as diligent management of these critically-ill patients in the postoperative period, prior to establishment of irreversible end-organ dysfunction. Our strategy has also helped us rationalize and optimize the use of this expensive treatment modality.

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%.

Huge thrombus formation in the left ventricle during bilateral CentriMag ventricular assist device with successful bridging to heart transplantation: a case report and review of the literature

Owing to shortage of donor hearts, the ventricular assist device is used as a bridging therapy to heart transplantation. However, thrombus formation is a critical complication during ventricular assist device circulatory support that might result in ischemic infarction of end organs. Here, we report a patient diagnosed with decompensated dilated cardiomyopathy and cardiogenic shock who underwent emergent extracorporeal life support, and subsequent temporary bilateral ventricular assistance with the CentriMag device (Levitronix LLC, Waltham, MA). Daily transthoracic echocardiography did not detect any thrombus formation, and no stroke event occurred during biventricular support. During eventual orthotopic heart transplantation, transesophageal echocardiography detected a huge thrombus in the left ventricle. We removed the biventricular assist device, excised the recipient heart, cleaned up the thrombus, and then implanted the donor heart successfully. No stroke or transient neurological deficit was noted during or after the transplantation. The patient was discharged 14 days after transplantation. No major adverse cardiovascular event was noted during 2 years of outpatient follow-up.

Short-term mechanical circulatory support devices as bridge to heart transplantation: A prospective single-center experience in Argentina

BACKGROUND

Patients with cardiogenic shock may require hemodynamic stabilization with short-term mechanical circulatory support devices (ST-MCS) such as extracorporeal membrane oxygenation (ECMO) and centrifugal pump (CP) as bridge to transplantion (BTT). This study aimed to describe ECMO and CP during BTT and after heart transplant.

METHODS

A cohort of patients on ECMO or CP as BTT between April 2006 and April 2018 in a single hospital.

RESULTS

Thirty-seven consecutive patients with ECMO (n = 14) or CP (n = 23) were included. Acute kidney injury was more prevalent during CP (28.6% vs 69.6%, P = .02). There were no differences in stroke, thrombosis, sepsis, or vasoplegia. Bleeding (0% vs 56.5%, P = .0003) and reoperation (0% vs 47.8%, P = .002) were more frequent in CP group as well as mortality (0 vs 7 [30.4%], P = .03). The remaining 30 patients (81.1%) underwent heart transplantation, without differences in primary graft dysfunction, vasoplegia, reoperation for bleeding, or hospital stay. Mortality was 23.3% at 30 days, similar in both groups, with no further deaths at median follow-up of 44.2 months.

CONCLUSIONS

In patients with cardiogenic shock, ST-MCS with ECMO or CP as BTT are a lifesaving approach allowing successful transplantation in the majority of cases, with good short- and long-term survival.

Outcomes of percutaneous temporary biventricular mechanical support: a systematic review

Percutaneous biventricular assist devices (BiVAD) are a recently developed treatment option for severe cardiogenic shock. This systematic review sought to identify indications and outcomes of patients placed on percutaneous BiVAD support. An electronic search was performed to identify all appropriate studies utilizing a percutaneous BiVAD configuration. Fifteen studies comprising of 20 patients were identified. Individual patient survival and outcomes data were combined for statistical analysis. All 20 patients were supported with a microaxial LVAD, 12/20 (60%) of those patients were supported with a microaxial (RMA) right ventricular assist device (RVAD), and the remaining 8/20 (40%) patients were supported with a centrifugal extracorporeal RVAD (RCF). All patients presented with cardiogenic shock, and of these, 12/20 (60%) presented with a non-ischemic etiology vs 8/20 (40%) with ischemic disease. For the RMA group, RVAD support was significantly longer [RMA 5 (IQR 4-7) days vs RCF 1 (IQR 1-2) days, p = 0.03]. Intravascular hemolysis post-BiVAD occurred in three patients (27.3%) [RMA 3 (33.3%) vs RCF 0 (0%), p = 0.94]. Five patients received a durable left ventricular assist device, one patient received a total artificial heart, and one patient underwent a heart transplantation. Estimated 30-day mortality was 15.0%, and 78.6% were discharged alive. Both strategies for percutaneous BiVAD support appear to be viable options for severe cardiogenic shock.

Use of a Virtual Mock Loop model to evaluate a new left ventricular assist device for transapical insertion

We are developing a novel type of miniaturized left ventricular assist device that is configured for transapical insertion. The aim of this study was to assess the performance and function of a new pump by using a Virtual Mock Loop system for device characterization and mapping. The results, such as pressure-flow performance curves, from pump testing in a physical mock circulatory loop were used to analyze its function as a left ventricular assist device. The Virtual Mock Loop system was programmed to mimic the normal heart condition, systolic heart failure, diastolic heart failure, and both systolic and diastolic heart failure, and to provide hemodynamic pressure values before and after the activation of several left ventricular assist device pump speeds (12,000, 14,000, and 16,000 r/min). With pump support, systemic flow and mean aortic pressure increased, and mean left atrial pressure and pulmonary artery pressure decreased for all heart conditions. Regarding high pump-speed support, the systemic flow, aortic pressure, left atrial pressure, and pulmonary artery pressure returned to the level of the normal heart condition. Based on the test results from the Virtual Mock Loop system, the new left ventricular assist device for transapical insertion may be able to ease the symptoms of patients with various types of heart failure. The Virtual Mock Loop system could be helpful to assess pump performance before in vitro bench testing.

Evaluation of in vitro hemolysis and platelet activation of a newly developed maglev LVAD and two clinically used LVADs with human blood

In vitro hemolysis testing remains one of the most important performance measures to judge the hemocompatibility of a left ventricular assist device (LVAD). Clinically relevant operating conditions and appropriate testing blood are essential to infer in vitro data for potential clinical use. This in vitro study was carried out to evaluate and compare the hemolytic performance of a newly developed magnetically levitated (maglev) LVAD (CH-VAD) with two clinically used LVADs (HVAD and HeartMate II (HMII)) using fresh human blood. A small volume (~300 mL) in vitro circulating flow loop was constructed with a LVAD generated flow of 4.5 L/min at the nominal or reported clinical operating speed for each LVAD. The blood was circulated in the loop for 4 hours with samples drawn at baseline and hourly. Plasma-free hemoglobin (PFH) concentrations in the hourly blood samples were determined with spectrophotometry. Normalized index of hemolysis (NIH) was calculated to compare the hemolytic performance of the CH-VAD and the two reference LVADs. Platelet activation was measured with flow cytometry. The experimental test for each device was repeated at least 7 times. The data from this study showed that all the three LVADs generated very low hemolysis (NIH <0.01 g/100 L). The CH-VAD was found to have a significantly lower NIH value (0.00135 ± 0.00032 g/100 L) compared to the HVAD (0.00525 ± 0.00183 g/100 L) and the HMII (0.00583 ± 0.00182 g/100 L). No statistically significant difference in device-generated hemolysis was found between the HVAD and the HMII. The level of platelet activation induced by the CH-VAD is significantly lower than those by the HVAD and the HMII. The data suggest that the shear-induced hemolysis and platelet activation of the CH-VAD are acceptable relative to the two LVADs currently in clinical use.

Turbulent Flow Promotes Cleavage of VWF (von Willebrand Factor) by ADAMTS13 (A Disintegrin and Metalloproteinase With a Thrombospondin Type-1 Motif, Member 13)

Objective—

Acquired von Willebrand syndrome is defined by excessive cleavage of the VWF (von Willebrand Factor) and is associated with impaired primary hemostasis and severe bleeding. It often develops when blood is exposed to nonphysiological flow such as in aortic stenosis or mechanical circulatory support. We evaluated the role of laminar, transitional, and turbulent flow on VWF cleavage and the effects on VWF function.

Approach and Results—

We used a vane rheometer to generate laminar, transitional, and turbulent flow and evaluate the effect of each on VWF cleavage in the presence of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type-1 motif, member 13). We performed functional assays to evaluate the effect of these flows on VWF structure and function. Computational fluid dynamics was used to estimate the flow fields and forces within the vane rheometer under each flow condition. Turbulent flow is required for excessive cleavage of VWF in an ADAMTS13-dependent manner. The assay was repeated with whole blood, and the turbulent flow had the same effect. Our computational fluid dynamics results show that under turbulent conditions, the Kolmogorov scale approaches the size of VWF. Finally, cleavage of VWF in this study has functional consequences under flow as the resulting VWF has decreased ability to bind platelets and collagen.

Conclusions—

Turbulent flow mediates VWF cleavage in the presence of ADAMTS13, decreasing the ability of VWF to sustain platelet adhesion. These findings impact the design of mechanical circulatory support devices and are relevant to pathological environments where turbulence is added to circulation.

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.

Diagnosis, medical treatment, and stepwise mechanical circulatory support for fulminat myocarditis

Fulminant myocarditis is one of the most challenging diseases. We sought to examine the outcomes of our multidisciplinary treatment strategy for fulminant myocarditis. A retrospective review of consecutive 30 patients with fulminant myocarditis was conducted. Of the 30 patients, 25 required mechanical circulatory support (MCS). Percutaneous extracorporeal membrane oxygenation (ECMO) was the first-line therapy to rescue the patients and inserted in 23 of them. The other 2 were implanted with temporary ventricular assist device (t-VAD) with extracorporeal centrifugal pump(s). Sixteen of the ECMO-supported patients were later transitioned to t-VAD. Of the 18 patients who underwent t-VAD support, heart function recovered and the VAD was explanted in 10. Four patients were bridged to long-term VAD and the other 4 died on t-VAD. Two patients were directly bridged to long-term VAD by ECMO. Heart function recovered only with ECMO in 4 patients and 1 died on ECMO. Overall survival rate was 83.3%. The duration of ECMO support significantly correlated with total bilirubin level, which was a significant risk factor for mortality. Pathologically, 7 patients (23.3%) had eosinophilic myocarditis and 1 (3.3%) had giant-cell myocarditis, and all the 8 patients underwent immunosuppressive therapy including steroids. Heart function recovered to normal level in 7 of them (87.5%). Timely conversion from the percutaneous ECMO to the temporary VAD before elevation of total bilirubin level is crucial for improving the clinical outcomes. Endomyocardial biopsy is needed to be done as soon as possible, because immunosuppressive therapy carries promising outcomes in certain etiologies.

Progressive spontaneous coronary artery dissection secondary to fibromuscular dysplasia requiring mechanical circulatory support

Spontaneous coronary artery dissection (SCAD) usually appears as an acute coronary syndrome with good prognosis. We present the case of a 39-year-old woman with progressive SCAD secondary to fibromuscular dysplasia with catastrophic course. The patient required several mechanical circulatory support systems including a left ventricular assist device (CentriMag^®, Thoratec, Pleasanton, CA, USA) as bridge to recovery. <Learning objective: The beneficial use of mechanical circulatory support devices as a bridge to recovery or heart transplant in the setting of refractory cardiogenic shock in spontaneous coronary artery dissection.>.

Rotary mechanical circulatory support systems

A detailed survey of the current trends and recent advances in rotary mechanical circulatory support systems is presented in this paper. Rather than clinical reports, the focus is on technological aspects of these rehabilitating devices as a reference for engineers and biomedical researchers. Existing trends in flow regimes, flow control, and bearing mechanisms are summarized. System specifications and applications of the most prominent continuous-flow ventricular assistive devices are provided. Based on the flow regime, pumps are categorized as axial flow, centrifugal flow, and mixed flow. Unique characteristics of each system are unveiled through an examination of the structure, bearing mechanism, impeller design, flow rate, and biocompatibility. A discussion on the current limitations is provided to invite more studies and further improvements.

Bridge to transplant or recovery in cardiogenic shock in a developing country

Background Durable mechanical support devices are prohibitively expensive in our health system and may be unsuitable for critically ill patients. CentriMag is an alternative bridge to transplantation or recovery. Methods We retrospectively reviewed 28 patients (23 males) aged 13-60 years who received CentriMag support. The etiology was ischemic in 13 (46%), dilated cardiomyopathy in 8 (29%), and others in 7 (25%). All patients were in Interagency Registry for Mechanically Assisted Circulatory Support class I, and 27 (96%) had multiorgan failure; 2 (7%) were post-cardiotomy and 12 (43%) had a previous cardiac arrest (mean arrest time 21 ± 17 min). Results Thirty-day post-implant survival was 79% (22 patients). Twenty (71%) patients were successfully bridged to transplantation or recovery. The mean support time was 40 days; 12 (43%) patients had >4-weeks' support (longest was 292 days). Eight (29%) patients died on support. Complications included bleeding in 10 (36%) cases, immediate stroke in 4 (14%), and dialysis in 8 (29%). There was no stroke during subsequent support. Eighteen (64%) patients underwent transplantation, and 17 of them were discharged. Two (7%) patients recovered and were discharged. Two-year survival was 62% ± 10%. Mean follow-up was 21 months (total follow-up 579 months). Two (7%) patients died during follow-up. All survivors were in New York Heart Association class I. Conclusions CentriMag is useful for medium-term support for cardiogenic shock in a developing country. Support for >4 weeks is feasible. The stroke rate is low during support. The major drawback is prolonged intensive care unit stay.

Short-Term Ventricular Assist Device as a Bridge to Decision in Cardiogenic Shock: Is It a Justified Strategy?

Purpose

Low cardiac output syndrome is associated with significant mortality. In patients with refractory low cardiac output left ventricular assist devices (VAD) are used to re-establish cardiac output and to prevent death. However, long-term LVAD implantation in these is complicated by a high rate of right heart failure and mortality. Therefore, our strategy is to implant a short-term VAD (left or biventricular) as a bridge to decission.

Methods

We retrospectively analysed data from 66 patients who received a short-term LVAD support prior to implantation of a long-term LVAD or HTx between 2003 and 2014. We performed short-term LVAD (CentriMag; Thoratec) implantation via median sternotomy with percutaneous cannulas. Patients were included regardless of perioperative status and severity of heart failure. Patients suffering postcardiotomy cardiogenic shock, receiving isolated RVAD as well as posttransplant patients were excluded from this study.

Results

Mean duration of support in the survivor group was 35 ± 25 days versus 25 ± 25 days in the nonsurvivor group (n.s.), range from 1 to 109 days. The overall survival on support was 40 (60%) patients. In the survivor group 12 patients could be successfully weaned from the system, 12 patients received a heart transplant and in 16 a long-term VAD was implanted. In the nonsurvivor group the rate of pre-operative extracorporeal life support, the rate of postoperative renal failure and multiorgan failure was significantly higher.

Conclusions

Thanks to its capacity for full ventricular support, short-term univentricular or biventricular LevotronixCentriMag VAD currently represents an ideal solution for bridge-to-decision.

Advanced mechanical circulatory support for post-cardiotomy cardiogenic shock: a 20-year outcome analysis in a non-transplant unit

Background

Post-cardiotomy cardiogenic shock (PCCS) has an incidence of 2–6 % after routine adult cardiac surgery. 0.5–1.5 % are refractory to inotropic and intra-aortic balloon pump (IABP) support. Advanced mechanical circulatory support (AMCS) can be used to salvage carefully selected number of such patients. High costs and major complication rates have lead to centralization and limited funding for such devices in the UK. We have looked the outcomes of such devices in a non-transplant, intermediate-size adult cardiothoracic surgery unit.

Methods

Inclusion criteria included any adult patient who had received salvage veno-arterial extra-corporeal membrane oxygenation (V-A ECMO) or a ventricular assist device (VAD) for PCCS refractory to IABP and inotropic support following cardiac surgery from April 1995-April 2015.

Results

Sixteen patients met the inclusion criteria. Age range was 34–83 years (median 71). There was a male predominance of 12 (75 %). Overall, 15 (94 %) had received ECMO of which, 10 (67 %) had received central ECMO and 5 (33 %) had received peripheral ECMO. One patient (6 %) had a VAD. The most common complication was haemorrhage. Stroke, femoral artery pseudo-aneurysm, sepsis and renal failure also occurred. Thirty-day survival was 37.5 %. Survival rate to hospital discharge was 31.2 %. All survivors had NYHA class I-II at 24 months follow-up.

Conclusions

Our survival rate is similar to that reported in several previous studies. However, the use of AMCS for refractory PCCS is associated with serious complications. The survivors in our cohort appear to maintain an acceptable quality of life.

Tissue plasminogen activator treatment of bilateral pulmonary emboli in a pediatric patient supported with a ventricular assist device

Bleeding and thrombosis are well-known potential complications of VAD support. We present a pediatric patient who developed massive bilateral pulmonary emboli while on BiVAD support that was successfully treated with intravenous tPA and bridged to heart transplant.

Thoratec CentriMag for temporary treatment of refractory cardiogenic shock or severe cardiopulmonary insufficiency: a systematic literature review and meta-analysis of observational studies

The aim of the study was to systematically evaluate effect of CentriMag heart pump (Thoratec Corporation) as temporary ventricular assist device (VAD) and part of extracorporeal membrane oxygenation (ECMO) system on outcomes in patients with cardiac or cardiac-respiratory failure. A systematic search was conducted in five databases for the period 2003 to 2012. Fifty-three publications with data for 999 patients, supported with CentriMag, were included. In 72% studies, CentriMag was used as a VAD and in 25% as part of ECMO circuit. Mean duration of VAD support was 25.0 days in precardiotomy group, 10.9 days in postcardiac surgery cardiogenic shock group, 8.8 days in post-transplant graft failure and rejection group, and 16.0 days in post-LVAD placement right ventricular failure group. Survival on support was 82% (95% CI 70-92) for VAD support in precardiotomy cardiogenic shock indication, 63% (95% CI 46-78) in VAD support in postcardiac surgery cardiogenic shock indication, 62% (95% CI 46-76) in VAD support in post-transplant graft rejection or failure indication, and 83% (95% CI 73-92) in VAD support in post-LVAD placement right ventricular failure indication. CentriMag is an effective technology for temporary support of patients with cardiac and cardiorespiratory failure.

Current state-of-the-art of device therapy for advanced heart failure

Heart failure remains one of the most common causes of morbidity and mortality worldwide. The advent of mechanical circulatory support devices has allowed significant improvements in patient survival and quality of life for those with advanced or end-stage heart failure. We provide a general overview of past and current mechanical circulatory support devices encompassing options for both short- and long-term ventricular support.

Results of extracorporeal life support implementation in routine clinical practice: single center experience

Aim

To describe our experience in the clinical application of extracorporeal life support (ECLS) and analyze whether ECLS leads to acceptable clinical outcomes in patients with cardiac failure.

Methods

Data from clinical database of University Hospital Center Zagreb, Croatia, on 75 patients undergoing ECLS support from 2009 to 2014 due to cardiac failure were retrospectively analyzed. Outcomes were defined as procedural and clinical outcomes. ECLS as a primary procedure and ECLS as a postcardiotomy procedure due to inability to wean from cardiopulmonary bypass were analyzed.

Results

ECLS was used in 75 adult patients, and in 24 (32%) of those procedural success was noted. ECLS was implemented as a primary procedure in 36 patients and as a postcardiotomy procedure in 39 patients. Nine out of 39 (23.08%) patients had postcardiotomy ECLS after heart transplantation. Bleeding complications occurred in 30 (40%) patients, both in primary (11/36 patients) and postcardiotomy group (19/39 patients). ECLS was established by peripheral approach in 46 patients and by central cannulation in 27 patients. In 2 patients, combined cannulation was performed, with an inflow cannula placed into the right atrium and an outflow cannula placed into the femoral artery. Eleven patients treated with peripheral approach had ischemic complications.

Conclusion

ECLS is a useful tool in the treatment of patients with refractory cardiac failure and its results are encouraging in patients who otherwise have an unfavorable prognosis.

Devices in heart failure--the new revolution

Heart failure is a growing epidemic, with more patients living longer and suffering from this disease. There is a growing segment of patients who have persistent symptoms despite pharmacologic therapy. In an era when transplants are rare, the need for devices and interventions that can assist ventricular function is paramount. This review goes through the devices used in heart failure, including left ventricular reconstruction, aortic counterpulsation, short-term mechanical circulatory support, long-term mechanical circulatory support, and right heart interventions.

Mitral valve and short-term ventricular assist devices; potential mechanical complications

Mechanical complications of ventricular assist devices (VADs) are rare but serious. The authors describe two cases of different mechanical complications of VADs that can affect the mitral valve. Attention should be paid to the position of the inflow/outflow cannula after off-loading of the ventricle, especially in acute heart failure and normal atrial dimensions. Complete off-loading of the left ventricle in the presence of a bioprosthetic mitral valve might cause fusion of the valve leaflets leading to mitral stenosis, which will call for another intervention.

Pearls and pitfalls in short-term mechanical circulatory assist: how to avoid and manage complications

In today's era, given the worsening risk profiles of patients undergoing cardiac surgery, the increasing number of complex cardiac surgeries, and the increasing number of patients undergoing thoracic organ transplantation, short-term mechanical circulatory assist (MCA) devices are indispensable. MCA devices are capable of supporting heart and lung function and have emerged as potentially lifesaving instruments, but may prove to be as hazardous as helpful due to their inherent tendency toward hemolysis, thromboembolism, and hemorrhage. Although MCA devices are being used regularly at some specialized centers, surgeries involving MCA are not as common as other routine cardiac surgeries, and even though professionals implanting and maintaining short-term MCAs are well acquainted with operating such devices, it is not uncommon to come across complications as a result of minor mistakes committed while dealing with them. Avoiding simple mistakes and taking proper precautions while implanting and maintaining these devices can prevent major catastrophes. We discuss commonly encountered problems and complications during the implantation and maintenance of short-term MCAs and offer reasonable and practical solutions. In addition, crucial issues such as anticoagulation, replacement of the device circuit, and management of the distal perfusion cannula are discussed. Continuous and efficient monitoring of the MCA device and the patient supported on MCA, together with anticipation and avoidance of complications, is key for successful short-term MCA support.

A comparison study of haemolysis production in three contemporary centrifugal pumps

One challenge in providing extracorporeal circulation is to supply optimal flow while minimising adverse effects, such as haemolysis. To determine if the recent generation constrained vortex pumps with their inherent design improvements would lead to reduced red cell trauma, we undertook a study comparing three devices. Utilizing a simulated short-term ventricular assist circuit primed with whole human blood, we examined changes in plasma free haemoglobin values over a six-day period. The three pumps investigated were the Maquet Rotaflow, the Levitronix PediVAS and the Medos Deltastream DP3.This study demonstrated that all three pumps produced low levels of haemolysis and are suitable for use in a clinical environment. The Levitronix PediVAS was significantly less haemolytic than either the Rotaflow (p<0.05) or the DP3 (p<0.05). There was no significant difference in plasma free haemoglobin between the Rotaflow and the DP3 (p=0.71).

Mechanical circulatory support: devices, outcomes and complications

Systolic heart failure is a problem of substantial magnitude worldwide. Over the last 25 years great progress has been made in the medical management of heart failure with the recognition of the benefits of beta-adrenergic blockade, modulation of the renin-angiotensin and mineralocorticoid axes and judicious diuretic therapy. In addition, cardiac resynchronization therapy and prophylactic implantation of cardiac defibrillators have been responsible for measurable benefits in terms of functional status and dysrhythmia-related mortality, respectively. Unfortunately, progressive cardiac dysfunction often results in activity limitation, symptoms at rest, hospital admission, end-organ dysfunction and death despite maximal implementation of standard therapies. Heart transplantation has been a dramatic and effective therapy for end-stage heart failure, but it remains limited by a shortage of donor organs, strict criteria defining acceptable recipients and often unsatisfactory long-term success. Mechanical alternatives to support the failing circulation have been sought for the last 50 years. The history of device development has been marked in general by the slow progress achieved by a few dedicated and persevering pioneers. In the past decade, however, evolving technology has dramatically changed the field and broadened the options for the treatment of advanced heart failure. This review will detail the important milestones and the current state of the art, with an emphasis on implantable devices for intermediate to long term support.

Use of a single-circuit CentriMag® for biventricular support in postpartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) is defined by acute heart failure in the late stages of pregnancy to a few months postpartum. Cardiogenic shock in PPCM, though rare, can be life-threatening, often requiring support with mechanical circulatory support devices. We present a case of 37-year-old Caucasian female who developed cardiogenic shock within 24 hours of the delivery of her twins. The echocardiogram demonstrated severe biventricular failure which necessitated biventricular device placement and support with a CentriMag® centrifugal pump. This biventricular support was employed, using a single-circuit CentriMag® pump, using a ‘Y’ connection which made weaning from right-sided support and conversion to univentricular support easier and feasible. The patient recovered four weeks later and was explanted off the CentriMag® support and did well. This technology allows for the CentriMag® to be considered as an early option for biventricular support in the treatment and management of these patients as a bridge to recovery.