Financial implications of using extracorporeal membrane oxygenation following heart transplantation

OBJECTIVES

Primary graft dysfunction after heart transplant is associated with high morbidity and mortality. Extracorporeal membrane oxygenation (ECMO) can be used to wean patients from cardiopulmonary bypass. This study retrospectively reviews a single-centre experience of post-transplant ECMO in regard to outcomes and associated costs.

METHODS

Between May 2006 and May 2019, a total of 267 adult heart transplants were performed. We compared donor and recipient variables, ECMO duration and the incidence of renal failure, bleeding, infection and cost analysis between ECMO and non-ECMO groups.

RESULTS

ECMO support was required postoperatively to manage primary graft dysfunction in 72 (27%) patients. The mean duration of ECMO support was 6 ± 3.2 days. Mean ischaemic times were similar between the groups. There was a significantly higher proportion of ventricular assist device explant to transplant in the ECMO group versus non-ECMO (38.2% vs 14.1%; P < 0.0001). ECMO patients had a longer duration of stay in the intensive care unit (P < 0.0001) and total hospital stay (P < 0.0001). Greater mortality was observed in the ECMO group (P < 0.0001). The median cost of providing ECMO was £18 000 [interquartile range (IQR): £12 750-£24 000] per patient with an additional median £35 225 (IQR: £21 487.25-£51 780.75) for ITU stay whilst on ECMO. The total median cost per patient inclusive of hospital stay, ECMO and dialysis costs was £65 737.50 (IQR: £52 566.50-£95 221.75) in the non-ECMO group compared to £145 415.71 (IQR: £102 523.21-£200 618.96) per patient in the ECMO group (P < 0.0001).

CONCLUSIONS

Patients with primary graft dysfunction following heart transplantation who require ECMO are frequently bridged to a recovery; however, the medium and longer-term survival for these patients is poorer than for patients who do not require ECMO.

Ultrasound-based prediction of interventricular septum positioning during left ventricular support-an experimental study

The implantation of left ventricular assist devices (LVADs) is often complicated by arrhythmias and right ventricular failure (RVF). Today, the pump speed is titrated to optimize device support using single observations of interventricular septum (IVS) positioning with echocardiographic ultrasound (US). The study demonstrates the applicability of three integrated US transducers in the LVAD cannula to monitor IVS positioning continuously and robustly in real time. In vitro, the predictor of the IVS shift shows an overall prediction error for all volume states of less than 20% and provides a continuous assessment for 99% of cases in four differently sized heart phantoms. The prediction of IVS shift depending on the cannula position is robust for azimuthal and polar deviations of ± 20° and ± 8°, respectively. This intracardiac US concept results in a viable predictor for IVS positioning and represents a promising approach to continuously monitor the IVS and ventricular loading in LVAD patients. Graphical abstract.

"BAX602" in Preventing Surgical Adhesion after Extracorporeal Ventricular Assist Device Implantation for Refractory Congestive Heart Failure: Study Protocol for a Multicenter Randomized Clinical Trial

BACKGROUND

The high surgical risk in redo cardiac surgery is largely attributed to adhesions around the epicardium and the great vessels. BAX602 is an adhesion prevention reagent composed of two synthetic polyethylene glycols. Spraying BAX602 over the epicardium and the great vessels reportedly contributes to adhesion prevention after pediatric cardiac surgery. The present study aims to evaluate the safety and effectiveness of BAX602 spray in patients undergoing extracorporeal ventricular assist device implantation surgery to treat refractory congestive heart failure.

METHODS AND DESIGN

This investigator-initiated, multicenter, pivotal, two-arm, open-label, randomized trial will include a total of 30 patients. The primary outcome measure is the severity of adhesions, which will be evaluated during re-sternotomy surgery performed 2-12 weeks after the primary extracorporeal ventricular assist device implantation surgery. The adhesion severity will be evaluated at five predefined sites using a four-grade adhesion evaluation score (0 = no adhesion; 1 = filmy and avascular adhesion; 2 = dense/vascular adhesion; 3 = cohesive adhesion). This measure will be summarized in two ways to evaluate the effect of BAX602: (1) the total score of the severity of adhesions at all five sites (ranging from 0 to 15), and (2) the total number of sites with dense/vascular or cohesive adhesions (ranging from 0 to 5).

ETHICS AND DISSEMINATION

The study findings will be disseminated at regional, national, and international conferences and through peer-reviewed scientific journals.

TRIAL REGISTRATION

The trial was registered in the UMIN Clinical Trials Registry (UMIN-CTR: UMIN000038998) on 6 January 2020.

Effects of left ventricular assist device on pulmonary functions and pulmonary hemodynamics: A meta-analysis

BACKGROUND

Given current evidence, the effect of left ventricular assist device (LVAD) implantation on pulmonary function tests remains controversial.

AIM

To better understand the factors contributing to the changes seen on pulmonary function testing and the correlation with pulmonary hemodynamics after LVAD implantation.

METHODS

Electronic databases were queried to identify relevant articles. The summary effect size was estimated as a difference of overall means and standard deviation on a random-effects model.

RESULTS

A total of four studies comprising 219 patients were included. The overall mean forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and diffusion lung capacity of carbon monoxide (DLCO) after LVAD implantation were significantly lower by 0.23 L (95%CI: 0.11-0.34, P = 00002), 0.18 L (95%CI: 0.03-0.34, P = 0.02), and 3.16 mmol/min (95%CI: 2.17-4.14, P < 0.00001), respectively. The net post-LVAD mean value of the cardiac index was significantly higher by 0.49 L/min/m² (95%CI: 0.31-0.66, P < 0.00001) compared to pre-LVAD value. The pulmonary capillary wedge pressure and pulmonary vascular resistance were significantly reduced after LVAD implantation by 8.56 mmHg (95%CI: 3.78-13.35, P = 0.0004), and 0.83 Woods U (95%CI: 0.11-1.55, P = 0.02), respectively. There was no significant difference observed in the right atrial pressure after LVAD implantation (0.61 mmHg, 95%CI: -2.00 to 3.32, P = 0.65). Overall findings appear to be driven by studies using HeartMateII devices.

CONCLUSION

LVAD implantation might be associated with a significant reduction of the spirometric measures, including FEV1, FVC, and DLCO, and an overall improvement of pulmonary hemodynamics.

Impact of bridge-to-bridge strategies from paracorporeal to implantable left ventricular assist devices on the pre-heart transplant outcome: A single-center analysis of 134 cases

BACKGROUND

In Japan, patients with heart failure who have a paracorporeal left ventricular assist device (pLVAD) and cannot be weaned from the VAD may undergo conversion to implantable continuous-flow LVAD (iLVAD) via a bridge-to-bridge (BTB) strategy for bridge-to-transplantation (BTT). This study aimed to evaluate the real-world clinical status of BTB strategies.

METHODS

Among 134 patients who underwent iLVAD implantation for BTT, 34 patients underwent conversion from pLVAD to iLVAD (BTB group) and 100 patients underwent iLVAD implantation primarily (primary iLVAD group). The clinical characteristics and outcomes were compared between the two groups.

RESULTS

No significant difference was found in the overall survival between the two groups (p = 0.26; log-rank test). However, the 1-year survival rate and the 1-year freedom from the composite events of death, stroke, systemic infection, and bleeding rate were lower in the BTB group than in the primary iLVAD group (survival rate, 88.2% vs. 99.0%, p = 0.0040; composite event-free survival rate, 26.1% vs. 49.8%, p = 0.030; log-rank test). Multivariate analysis indicated that the BTB strategy [hazard ratio (HR) 1.70, 95% confidence intervals (CI) 1.03-2.72; p=0.036] and serum total bilirubin levels at iLVAD implantation [HR 1.31, 95% CI 1.00-1.65; p=0.043] were independent predictors of 1-year composite events.

CONCLUSIONS

The BTB strategy is useful in providing long-term survival in patients with acute critical diseases. However, the early mortality rate after conversion is higher in patients who underwent the BTB strategy.

Durable ventricular assist device implantation for systemic right ventricle: a case series

Background

A systemic right ventricle (RV) after atrial switch in transposition of the great arteries (TGA) or congenitally corrected TGA (ccTGA) often results in advanced heart failure in adulthood.

Case summary

Four patients with INTERMACS Class III underwent durable ventricular assist device (VAD) implantation for a systemic RV. Two patients were diagnosed with ccTGA and underwent tricuspid valve replacement, and two were diagnosed with TGA in childhood and underwent Mustard repair. The two patients with ccTGA received an EVAHEART (Sun Medical, Nagano, Japan) and HeartMate 3 (Abbott Laboratories, Abbott Park, IL, USA) at the age of 56 years and 34 years, respectively. Of the patients with TGA, one received a Heartmate II at age 40 years, and one received a HeartMate 3 at age 40 years. All patients were weaned from cardiopulmonary bypass without subpulmonic VAD support and transferred to the intensive care unit with optimum VAD support. No in-hospital deaths, cerebrovascular accidents, or other major complications occurred. The post-VAD right heart catheter study showed a remarkable reduction in pulmonary capillary wedge pressure in all patients.

Discussion

The indications for and surgical technique of durable VAD implantation for a systemic RV after atrial switch of TGA or ccTGA have not been fully established. A durable VAD, including the HeartMate 3, was successfully implanted in four such patients in this study. Pre-operative three-dimensional computed tomography images and intraoperative transoesophageal echocardiography guidance helped to determine the positions of the inflow and pump.

Accuracy of Doppler blood pressure measurement in HeartMate 3 ventricular assist device patients

Aims

Optimal blood pressure (BP) control is imperative to reduce complications, especially strokes, in continuous flow ventricular assist device (VAD) patients. Doppler BP has been shown to be an accurate and reliable non‐invasive BP measurement method in HeartMate II and HVAD patients. We examined whether Doppler BP is also accurate in patients with the HeartMate 3 VAD.

Methods and results

In a prospective, longitudinal cohort of HeartMate 3 patients, arterial line BP and simultaneously measured Doppler opening pressure were obtained. Correlation and agreement between Doppler opening pressure and arterial line mean arterial pressure (MAP) versus systolic blood pressure (SBP) were analysed, as well as the effect of pulse pressure on the accuracy of Doppler opening pressure.

A total of 589 pairs of simultaneous Doppler opening pressure and arterial line pressure readings were obtained in 43 patients. Doppler opening pressure had good correlation with intra‐arterial MAP (r = 0.754) and more closely approximated MAP than SBP (mean error 2.0 vs. −8.6 mmHg). Pulse pressure did not have a clinically significant impact on the accuracy of the Doppler BP method. These results in HeartMate 3 patients are very similar to previous results in HeartMate II and HVAD patients.

Conclusions

Doppler BP method should be the default non‐invasive BP measurement method in continuous flow VAD patients including patients implanted with the HeartMate 3.

Mechanical Support of the Failing Fontan Circulation

The Fontan is the final common pathway for most single ventricle lesions. It is not a durable circulation and many Fontan patients eventually present for advanced heart failure therapies including mechanical circulatory support. While there have been advancements in available durable devices, many pediatric patients have size, anatomical, and physiologic constraints that make placement of adult ventricular assist devices challenging. And, Fontan failure comes in different varieties, including failure with preserved systolic function. This subset of patients requires either a subpulmonary assist device or a total artificial heart. Unique operative maneuvers, including atrial cannulation and atrioventricular valve manipulation have allowed many failing Fontan patients to be bridged to transplant after recovery of end-organ dysfunction and improved nutrition. The Advanced Cardiac Therapies Improving Outcomes Network is a multicenter learning network of pediatric hospitals implanting, managing, and studying ventricular assist devices in children and adults with congenital heart disease. This network is advancing the knowledge of outcomes and approaches to mechanical circulatory support in those with congenital heart disease, including Fontans. The congenital heart disease community continues to work toward and hope for a smaller durable device that will help this complex cohort of patients.

Pathophysiology and molecular signalling in pediatric heart failure and VAD therapy

Heart Failure (HF) is a progressive clinical syndrome characterized by molecular and structural abnormalities that result in impaired ventricular filling and a reduced blood ejection. In pediatric patients, HF represents an important cause of morbidity and mortality, but underlying cause, presentation and disease course remains unclear in many cases. It is evident that a child is not a "small adult" and findings are not comparable. The adoption of a standardized clinical and surgical tools as well as increased biomolecular research and therapeutic trials targeting pediatric patients with HF would greatly improve the management of this special class of patients. This review examines the most current information about the pathophysiology and molecular mechanisms related to HF in children to identify gaps in our knowledge base to further improve clinical care and outcomes.

Management of COVID-19 in a durable left ventricular assist device recipient: A continuity of care perspective

COVID-19 is impacting the cardiovascular community both here in the United States and globally. The rapidly emerging cardiac complications have heightened implications for those with underlying cardiovascular disease. We describe an early case of COVID-19 in a left ventricular assist device recipient in the United States. We discuss our clinical management during the initial admission, outpatient management, and a unique complication of this disease over a 40-day disease course.

Computed tomography perfusion in patients of stroke with left ventricular assist device

Left ventricular assist devices (LVAD) are widely applied for patients with severe heart failure as a bridge to heart transplantation as well as destination therapy. Patients with implanted LVAD have an increased risk of cerebral thrombosis and computed tomographic perfusion (CTP) has the potential to be performed for early diagnosis and treatment of acute ischemic stroke (AIS), including interventional thrombectomy. Here, we report our series of CTP examination in patients having suspected AIS after LVAD implantation. We retrospectively investigated 33 contrast-enhanced CTPs from January 2017 to December 2018 which were performed in 12 cases of patients because of possible neurological findings leading to suspected AIS during LVAD circulatory support who did not have definite ischemic findings nor intracerebral hemorrhage on non-contrast computed tomography. AIS with perfusion disturbance area was diagnosed in 11 (33.3%) out of a total of 33 CTPs in 4 (33.3%) out of 12 patients. Endovascular thrombectomy (EVT) was successfully performed in this research study four times for three patients. CTP was able to detect and determine the indication for EVT without serious complications. CTP could potentially be the first-choice assessment for early diagnosis of AIS with recoverable ischemic penumbra in patients with LVAD implantation.

Evaluation method and platform of vibrational disturbance test for ventricular assist devices

OBJECTIVE

For ventricular assist devices utilizing levitation bearing technology, collision and wear of the rotor would occur if the bearing cannot resist disturbances from patient activities and vibration/shock impacts. The reliability of ventricular assist devices can be seriously affected, potentially impairing blood compatibility (e.g. thrombus generation) and threatening patient safety. In this article, we proposed a vibrational disturbance test protocol for ventricular assist devices.

METHODS

Two kinds of vibrational disturbances-translational and rotational-were defined and the disturbance levels determined as 6G and 10 rad/s per possible patient activity impact. A test platform was built according to the disturbance level requirements.

RESULTS

The test platform successfully generated the required disturbance. The vibration test evaluation criteria for ventricular assist device assistance (characterized by the pressure head, flow rate, and driving current waveform) were well verified.

CONCLUSION

Compared with translational vibration, rotational vibration had a greater impact on the rotor. Accurate control of high-speed rotor is difficult because of the gyroscopic effect. As conventional random vibration tests cannot cover all risk situations, it is recommended that translational and rotational disturbance tests are carried out for levitation ventricular assist devices. We recommend that researchers and manufacturers pay attention to the vibrational impact of rotor-levitated ventricular assist devices.

Comprehensive review of hemolysis in ventricular assist devices

Ventricular assist devices (VADs) have played an important role in altering the natural history of end-stage heart failure. Low-grade hemolysis has been traditionally described in patients with VADs, indicating effective device functionality. However, clinically significant hemolysis could be crucial in terms of prognosis, calling for prompt therapeutic actions. The absence of solid and widely approved diagnostic criteria for clinically significant hemolysis, render the utilization of hemolysis laboratory markers challenging. Hemolysis incidence varies (5%-18%) depending on definition and among different VAD generations, being slightly higher in continuous-flow devices than in pulsatile devices. Increased shear stress of red blood cells and underlying device thrombosis appear to be the main pathogenetic pathways. No certain algorithm is available for the management of hemolysis in patients with VADs, while close clinical and laboratory monitoring remains the cornerstone of management. Imaging examinations such as echocardiography ramp test or computed tomography scan could play a role in revealing the underlying cause. Treatment should be strictly personalized, including either pharmacological (antithrombotic treatment) or surgical interventions.

Detection of acquired von Willebrand syndrome after ventricular assist device by total thrombus-formation analysis system

AIMS

Bleeding is a serious complication in patients with continuous-flow left ventricular assist device (CF-LVAD). Acquired von Willebrand syndrome (AVWS; type 2A) develops because of high shear stress inside the pumps and is a cause of bleeding complication. Although von Willebrand factor (vWF) multimer analysis is useful for diagnosing AVWS, it is only performed in specialized research institutes. A novel microchip flow chamber system, the total thrombus-formation analysis system (T-TAS), is a point-of-care system to evaluate the thrombus-formation process and useful for monitoring platelet thrombus-formation capacity in patients receiving antiplatelet therapy and the diagnosis and evaluation of the clinical severity of von Willebrand disease type 1. However, little is known about the association between AVWS and platelet thrombus-formation capacity evaluated by T-TAS in patients with CF-LVAD. We aimed to evaluate the utility of T-TAS for easy detection of AVWS in patients with CF-LVAD.

METHODS AND RESULTS

We simultaneously evaluated the vWF large multimers and T-TAS parameters in four consecutive patients with axial-type CF-LVAD and eight control patients treated with aspirin and warfarin. vWF large multimer index was defined as the proportion of large multimers in total vWF derived from a normal control plasma. T-TAS analyses different thrombus-formation processes using two microchips with different thrombogenic surfaces. PL₂₄ -AUC₁₀ levels in the platelet (PL) chip are highly sensitive for platelet functions, while AR₁₀ -AUC₃₀ levels in the atheroma (AR) chip allow the assessment of the overall haemostatic ability. vWF large multimer index and T-TAS parameters were decreased in all patients with CF-LVAD. The mean PL₂₄ -AUC₁₀ level (5.4 ± 2.9 vs. 219 ± 67; P < 0.01), AR₁₀ -AUC₃₀ level (338 ± 460 vs. 1604 ± 160; P < 0.01) and vWF large multimer index (49 ± 11% vs. 112 ± 27%; P < 0.01) were significantly lower in the patients with CF-LVAD than in control patients. One patient showed changes in T-TAS levels before and after implantation of CF-LVAD. PL₂₄ -AUC₁₀ and AR₁₀ -AUC₃₀ levels decreased from 438.1 to 5.0 and from 1667.9 to 1134.3, respectively.

CONCLUSIONS

In patients with CF-LVAD, the platelet thrombus-formation capacity was extremely impaired because of AVWS, and T-TAS parameters could detect the presence of AVWS. T-TAS can be used for easy detection of AVWS as a point-of-care testing. Further studies with a large sample size are needed to validate our results in several LVAD models and evaluate the prognostic value of bleeding complications and thromboembolism in patients with LVAD.

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.

Berlin Heart EXCOR Support in the First Year of Life: A Single Centre Experience

BACKGROUND

Berlin Heart EXCOR Pediatric Ventricular Assist Device (BHE) (Berlin Heart AG, Berlin, Germany, BHE) is used worldwide for mechanical circulatory support as a bridge to transplantation or recovery for children with end-stage heart failure. The study aim was to evaluate morbidity and mortality of children less than one year old supported with BHE to identify predictors of adverse outcomes.

METHODS

Data of all children aged less than one year supported with BHE between 2005 and 2018 at the Royal Children's Hospital, Melbourne were reviewed. Adverse events were defined using PediMACS criteria.

RESULTS

Fourteen (14) children under 1 year of age were implanted with BHE at a median age and weight of 0.37 years (IQR 0.09-0.7) and 5.7 kg (IQR 3.5-7.95) respectively. Four (4) patients were neonates, and 10 were older infants. Twelve (12) patients had cardiomyopathy and two, myocarditis. Preoperative extracorporeal membrane oxygenation (ECMO) support was required in six patients for a mean of 9 days (IQR 6-13). Sepsis occurred in five patients (36%) and thromboembolic stroke in two patients (14%). Survival to bridge to transplantation (11) and recovery (1) was achieved in 12 patients (86%). Mortality was 14%. The median duration of BHE support was 110 days (IQR 40-161). Both patients who died were neonates with myocarditis and required surgical re-intervention during BHE support.

CONCLUSIONS

BHE provides excellent support as a bridge to transplantation or recovery in infants, with a low incidence of neurological dysfunction. Neonates with myocarditis may be at greater risk for death after BHE implantation.

Thoracoscopic repair of diaphragmatic hernia following ventricular assist device implantation

Background

Diaphragmatic hernia is a rare complication of ventricular assist device (VAD), mainly developing after explantation of the device. We herein report a case of diaphragmatic hernia that developed following the implantation of VAD.

Case presentation

A 4-month-old girl with a diagnosis of dilated cardiomyopathy underwent VAD implantation for a bridge to heart transplantation. Three months later, intermittent vomiting developed, and left-sided diaphragmatic hernia was confirmed on plain X-ray and computed tomography. Without any findings of ischemia, we performed elective thoracoscopic repair of the diaphragmatic hernia. In the right decubitus position, thoracoscopy revealed the small intestine to be herniated into the left thorax. After reduction of the herniated intestine, the defect of the diaphragm (3 × 2 cm in size) was directly closed with interrupted non-absorbable sutures. Her postoperative course was uneventful.

Conclusion

Thoracoscopic repair of diaphragmatic hernia associated with VAD implantation may be a safe approach.

Computational modeling of a right-sided Fontan assist device: Effectiveness across patient anatomies and cannulations

The use of mechanical circulatory support for failing Fontan patients is an area of growing interest, as the increased life expectancy of these patients continues to be accompanied by numerous end-organ complications. In vitro work has shown positive results using the CentriMag device for right-sided Fontan support, however the generalizability across various patient anatomies and cannulations is unknown. Computational simulations are first validated against in vitro modeling, then used to assess generalizability and further explore hemodynamic metrics including relative pressure changes, hepatic flow distribution, wall shear stress and power added. Computational modeling matched previous in vitro work very well, with vessel flow rates and relative average pressure change each within 1%. Positive results were seen across all patient anatomies and cannulations. On average, pressure from the vena cava to pulmonary arteries increased by 5.4 mmHg corresponding to 32 mW of power added. Hepatic flow distribution and wall shear stress were within acceptable ranges, with an average hepatic flow distribution of 47% and all patients showing ≤ 1% of the total Fontan connection surface area at a wall shear stress above 150 Pa. The positive results previously seen using CentriMag as a right-sided Fontan support device were found to be repeatable across multiple patient anatomies and cannulations. While animal models and eventual patient studies will provide further insight into the efficacy of this support strategy, our findings here suggest this method may reproduce right heart function.

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.

Left Ventricular Assist Device Exchange Increases Heart Transplant Wait-List Mortality

BACKGROUND

The new heart transplant allocation criteria prioritize inpatients who require temporary mechanical circulatory support and give lower urgency to candidates on a durable left ventricular assist device (LVAD) who require a device exchange. This study explores whether the latter group should warrant higher priority to reduce wait-list mortality.

METHODS

This is a retrospective observational study of 13,113 adult heart transplant candidates in the Organ Procurement and Transplantation Network database who underwent LVAD implantation between 2007 and 2017. It evaluates the impact of LVAD exchange on the composite endpoint of death or removal from the wait list owing to worsening medical condition 1 y after device implantation.

RESULTS

There were 1085 pump exchanges in 954 patients (7% of candidates), of which 22% were women. The pump exchange rate was 5.92 events per 100 patient-years. One-year survival was lower for those who required a pump exchange (76.3% versus 88.5%, logrank P < 0.001). This was congruent with the risk-adjusted mortality 1-y after implantation (hazards ratio: 2.56, 95% confidence interval: 2.18-3.00, P < 0.001).

CONCLUSIONS

These findings indicate that among candidates awaiting heart transplantation with a durable LVAD, undergoing pump exchange doubles the risk of 1-y mortality. Giving priority to these candidates may reduce wait-list mortality.

Hemolysis and methemoglobinemia in a child with left ventricular assist Levitronix PediMag

A 5-month-old male was treated with left ventricular assist device due to cardiac failure secondary to dilated cardiomyopathy. The patient developed acute severe intravascular hemolysis with methemoglobinemia and renal failure, related to a mechanical problem due to pump cylinder misalignment. Secondary severe methemoglobinemia has not been previously described in patients undergoing ventricular assist device. Early detection of the signs and symptoms of hemolysis is crucial to prevent further complications.

Quality of economic evaluations of ventricular assist devices: A systematic review

OBJECTIVE

Because of a lack of suitable heart donors, alternatives to transplantation are required. These alternatives can have high costs. The aim of this study was to perform a systematic review of cost-effectiveness studies of ventricular assist devices (VADs) and to assess the level of evidence of relevant studies. The purpose was not to present economic findings.

METHODS

A systematic review was performed using four electronic databases to identify health economic evaluation studies dealing with VADs. The methodological quality and reporting quality of the studies was assessed using three different tools, the Drummond, Cooper, and CHEERS (Consolidated Health Economic Evaluation Reporting Standards) checklists.

RESULTS

Of the 1,258 publications identified, thirteen articles were included in this review. Twelve studies were cost-utility analyses and one was a cost-effectiveness analysis. According to the Cooper hierarchy scale, the quality of the data used was heterogeneous. The level of evidence used for clinical effect sizes, safety data, and baseline clinical data was of poor quality. In contrast, cost data were of high quality in most studies. Quality of reporting varied between studies, with an average score of 17.4 (range 15-19) according to the CHEERS checklist.

CONCLUSION

The current study shows that the quality of clinical data used in economic evaluations of VADs is rather poor in general. This is a concern that deserves greater attention in the process of health technology assessment of medical devices.

Right heart failure before LVAD implantation predicts right heart failure after LVAD implantation - is it that easy?

Background

Right heart failure (RHF) after left ventricular assist device (LVAD) implantation is common and associated with worse outcome. Prediction of RHF remains challenging. Our study aims to assess predictors of RHF focusing on clinical manifestations.

Methods

We retrospectively analyzed clinical, echocardiographic and hemodynamic parameters of 112 patients undergoing LVAD implantation. Pre-operative, early (ERHF, day 7 and 14) and late postoperative RHF (LRHF, after 1, 3, 6 and 12 months) were assessed.

Results

In the total study population (87.5% men, mean age 55 years), early RHF was frequent (47% on day 7 and 30% on day 14). Prevalence of late RHF and death from RHF was high after 3, 6 and 12 months (23, 24 and 17%). Pre-existing RHF was only associated with early RHF and persistent, but not for new onset late RHF. Early RHF was associated with lower INTERMACS level (p < 0.001), higher pulmonary vascular resistance (p = 0.046) and CVP/PAWP quotient (p = 0.011), higher bilirubin (p = 0.038) and creatinine (p = 0.013). LRHF was associated with creatinine (p = 0.006), urea (p = 0.012) and load adaption index (p = 0.007). Binary logistic regression models identified no single risk factors. Comparing the predictive value of regression models with a model of three clinical findings (INTERMACS level, age and pre-operative RHF) did not reveal differences in RHF.

Conclusions

RHF before LVAD implantation enhances the risk of early RHF and persistent late RHF, but not for new onset late RHF, supporting the hypothesis of differences in the etiology. Echocardiographic or hemodynamic parameters did not show a predictive value for new onset late RHF. Similar predictive value of clinical findings and statistic models of risk factors suggest that a clinical evaluation is equally matched to predict RHF.

Long term CentriMag biventricular support using hybrid cannulation as a bridge to transplant in a pediatric patient

Paracorporeal continuous-flow ventricular assist devices designed for short-term support can also potentially provide long-term circulatory support as bridges to transplantation in children. We describe the long-term use of the CentriMag biventricular assist device with multiple pump changes in a 9-year-old boy with idiopathic-dilated cardiomyopathy. The initially implanted Berlin Heart EXCOR pumps were replaced by CentriMag due to thromboembolic complications. The CentriMag pumps were exchanged 15 times due to clot and fibrin formation or when the pumps reached their expiration dates. Connecting CentriMag to Berlin Heart EXCOR cannulae effectively served as an alternative long-term hybrid bridge to transplantation for 235 days. The patient successfully underwent a transplant after 284 days. Judicious pump monitoring and timely pump exchanges can potentially overcome device-related complications and extend the duration on support.