Survival After Left Ventricular Assist Device With and Without Temporary Right Ventricular Support

Central Venopulmonary Extracorporeal Membrane Oxygenation: Background and Standardized Nomenclature

This review highlights advancements in extracorporeal life support (ECLS), emphasizing the critical role of standardized terminology, particularly for extracorporeal membrane oxygenation (ECMO) in treating right ventricular and respiratory failure. Advocating for the adoption of the Extracorporeal Life Support Organization (ELSO) Maastricht Treaty for ECLS Nomenclature guidelines, it aims to resolve communication barriers in the ECMO field. Focusing on venopulmonary (VP) ECMO utilizing central pulmonary artery (PA) access, this review details surgical approaches and introduces a terminology guide to support effective knowledge exchange and advancements in patient care.

Right Ventricular Assist Device Placement During Left Ventricular Assist Device Implantation Is Associated With Improved Survival

Right ventricular failure (RVF) is a significant cause of mortality in patients undergoing left ventricular assist device (LVAD) implantation. Although right ventricular assist devices (RVADs) can treat RVF in the perioperative LVAD period, liberal employment before RVF is not well established. We therefore compared the survival outcomes between proactive RVAD placement at the time of LVAD implantation with a bailout strategy in patients with RVF. Retrospectively, 75 adult patients who underwent durable LVAD implantation at our institution and had an RVAD placed proactively before LVAD implantation or as a bailout strategy postoperatively due to hemodynamically unstable RVF were evaluated. Patients treated with a proactive RVAD strategy had lower Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) and a higher proportion of these required temporary mechanical circulatory support (MCS) preoperatively. Preoperative hemodynamic profiling showed a low pulmonary artery pulsatility index (PAPi) score of 1.8 ± 1.4 and 1.6 ± 0.94 ( p = 0.42) in the bailout RVAD and proactive RVAD groups, respectively. Survival at 3, 6, and 12 months post-LVAD implantation was statistically significantly higher in patients who received a proactive RVAD. Thus, proactive RVAD implantation is associated with short- and medium-term survival benefits compared to a bailout strategy in RVF patients undergoing LVAD placement.

Right heart failure with left ventricular assist devices: Preoperative, perioperative and postoperative management strategies. A clinical consensus statement of the Heart Failure Association (HFA) of the ESC

Right heart failure (RHF) following implantation of a left ventricular assist device (LVAD) is a common and potentially serious condition with a wide spectrum of clinical presentations with an unfavourable effect on patient outcomes. Clinical scores that predict the occurrence of right ventricular (RV) failure have included multiple clinical, biochemical, imaging and haemodynamic parameters. However, unless the right ventricle is overtly dysfunctional with end-organ involvement, prediction of RHF post-LVAD implantation is, in most cases, difficult and inaccurate. For these reasons optimization of RV function in every patient is a reasonable practice aiming at preparing the right ventricle for a new and challenging haemodynamic environment after LVAD implantation. To this end, the institution of diuretics, inotropes and even temporary mechanical circulatory support may improve RV function, thereby preparing it for a better adaptation post-LVAD implantation. Furthermore, meticulous management of patients during the perioperative and immediate postoperative period should facilitate identification of RV failure refractory to medication. When RHF occurs late during chronic LVAD support, this is associated with worse long-term outcomes. Careful monitoring of RV function and characterization of the origination deficit should therefore continue throughout the patient's entire follow-up. Despite the useful information provided by the echocardiogram with respect to RV function, right heart catheterization frequently offers additional support for the assessment and optimization of RV function in LVAD-supported patients. In any patient candidate for LVAD therapy, evaluation and treatment of RV function and failure should be assessed in a multidimensional and multidisciplinary manner.

Perioperative Right Ventricular Dysfunction and Abnormalities of the Tricuspid Valve Apparatus in Patients Undergoing Cardiac Surgery

Right ventricular (RV) dysfunction frequently occurs after cardiac surgery and is linked to adverse postoperative outcomes, including mortality, reintubation, stroke, and prolonged ICU stays. While various criteria using echocardiography and hemodynamic parameters have been proposed, a consensus remains elusive. Distinctive RV anatomical features include its thin wall, which presents a triangular shape in a lateral view and a crescent shape in a cross-sectional view. Principal causes of RV dysfunction after cardiac surgery encompass ischemic reperfusion injury, prolonged ischemic time, choice of cardioplegia and its administration, cardiopulmonary bypass weaning characteristics, and preoperative risk factors. Post-left ventricular assist device (LVAD) implantation RV dysfunction is common but often transient, with a favorable prognosis upon resolution. There is an ongoing debate regarding the benefits of concomitant surgical repair of the RV in the presence of regurgitation. According to the literature, the gold standard techniques for assessing RV function are cardiac magnetic resonance imaging and hemodynamic assessment using thermodilution. Echocardiography is widely favored for perioperative RV function evaluation due to its accessibility, reproducibility, non-invasiveness, and cost-effectiveness. Although other techniques exist for RV function assessment, they are less common in clinical practice. Clinical management strategies focus on early detection and include intravenous drugs (inotropes and vasodilators), inhalation drugs (pulmonary vasodilators), ventilator strategies, volume management, and mechanical support. Bridging research gaps in this field is crucial to improving clinical outcomes associated with RV dysfunction in the near future.

Prediction, prevention, and management of right ventricular failure after left ventricular assist device implantation: A comprehensive review

Left ventricular assist devices (LVADs) are increasingly common across the heart failure population. Right ventricular failure (RVF) is a feared complication that can occur in the early post-operative phase or during the outpatient follow-up. Multiple tools are available to the clinician to carefully estimate the individual risk of developing RVF after LVAD implantation. This review will provide a comprehensive overview of available tools for RVF prognostication, including patient-specific and right ventricle (RV)-specific echocardiographic and hemodynamic parameters, to provide guidance in patient selection during LVAD candidacy. We also offer a multidisciplinary approach to the management of early RVF, including indications and management of right ventricular assist devices in this setting to provide tools that help managing the failing RV.

Days alive and out of hospital after left ventricular assist device implantation

AIMS

Implantation of left ventricular assist devices (LVADs) as a bridge to transplant or as destination therapy is increasing. The selection of suitable patients and outcome assessment belong to the key challenges. Mortality has traditionally been a focus of research in this field, but literature on quality of life is very limited. This study aimed to identify perioperative factors influencing patients' life as measured by days alive and out of hospital (DAOH) in the first year after LVAD implantation.

METHODS AND RESULTS

This retrospective single-centre cohort study screened 227 patients who underwent LVAD implantation at the University Hospital Duesseldorf, Germany, between 2010 and 2020. First, the influence of 10 prespecified variables on DAOH was investigated by univariate analysis. Second, multivariate quantile regression was conducted including all factors with significant influence on DAOH in the univariate model. Additionally, the impact of all variables on 1 year mortality was investigated using Kaplan-Meier curves to oppose DAOH and mortality. In total, 221 patients were included into analysis. As pre-operative factors, chronic kidney disease (CKD), pre-operative mechanical circulatory support (pMCS), and Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) stadium < 3 were associated with lower DAOH at 1 year [CKD: 280 (155-322) vs. 230 (0-219), P = 0.0286; pMCS: 294 (155-325) vs. 243 (0-293), P = 0.0004; INTERMACS 1: 218 (0-293) vs. INTERMACS 2: 264 (6-320) vs. INTERMACS 3: 299 (228-325) vs. INTERMACS 4: 313 (247-332), P ≤ 0.0001]. Intra-operative additional implantation of a right ventricular assist device (RVAD) was also associated with lower DAOH [RVAD: 290 (160-325) vs. 174 (0-277), P ≤ 0.0001]. As post-operative values that were associated with lower DAOH, dialysis and tracheotomy could be identified [dialysis: 300 (252-326) vs. 186 (0-300), P ≤ 0.0001; tracheotomy: 292 (139-325) vs. 168 (0-269), P ≤ 0.0001]. Multivariate analysis revealed that all of these factors besides pMCS were independently associated with DAOH. According to Kaplan-Meier analysis, only post-operative dialysis was significantly associated with increased mortality at 1 year (survival: no dialysis 89.4% vs. dialysis 70.1%, hazard ratio: 0.56, 95% confidence interval: 0.33-0.94; P = 0.031).

CONCLUSIONS

The results of this study indicate that there can be a clear discrepancy between hard endpoints such as mortality and more patient-centred outcomes reflecting life impact. DAOH may relevantly contribute to a more comprehensive selection process and outcome assessment in LVAD patients.

Temporary Right-Ventricular Assist Devices: A Systematic Review

Acute right-sided heart failure (RHF) is a complex clinical syndrome, with a wide range of clinical presentations, associated with increased mortality and morbidity, but about which there is a scarcity of evidence-based literature. A temporary right-ventricular assist device (t-RVAD) is a potential treatment option for selected patients with severe right-ventricular dysfunction as a bridge-to-recovery or as a permanent solution. We sought to conduct a systematic review to determine the safety and efficacy of t-RVAD implantation. Thirty-one studies met the inclusion criteria, from which data were extracted. Successful t-RVAD weaning ranged between 23% and 100%. Moreover, 30-day survival post-temporary RAVD implantation ranged from 46% to 100%. Bleeding, acute kidney injury, stroke, and device malfunction were the most commonly reported complications. Notwithstanding this, t-RVAD is a lifesaving option for patients with severe RHF, but the evidence stems from small non-randomized heterogeneous studies utilizing a variety of devices. Both the etiology of RHF and time of intervention might play a major role in determining the t-RVAD outcome. Standardized endpoints definitions, design and methodology for t-RVAD trials is needed. Furthermore, efforts should continue in improving the technology as well as improving the timely provision of a t-RVAD.

Weaning from ventricular assist device support after recovery from left ventricular failure with or without secondary right ventricular failure

Although complete myocardial recovery after ventricular assist device (VAD) implantation is rather seldom, systematic search for recovery is worthwhile because for recovered patients weaning from VADs is feasible and can provide survival benefits with long-term freedom from heart failure (HF) recurrence, even if a chronic cardiomyopathy was the primary cause for the drug-refractory HF necessitating left ventricular (LVAD) or biventricular support (as bridge-to-transplantation or definitive therapy) and even if recovery remains incomplete. LVAD patients explanted for myoacardial recovery compared to those transplanted from LVAD support showed similar survival rates and a significant proportion of explanted patients can achieve cardiac and physical functional capacities that are within the normal range of healthy controls. In apparently sufficiently recovered patients, a major challenge remains still the pre-explant prediction of the weaning success which is meanwhile reliably possible for experienced clinicians. In weaning candidates, the combined use of certain echocardiography and right heart catheterization parameters recorded before VAD explantation can predict post-weaning cardiac stability with good accuracy. However, in the absence of standardization or binding recommendations, the protocols for assessment of native cardiac improvement and also the weaning criteria differ widely among centers. Currently there are still only few larger studies on myocardial recovery assessment after VAD implantation. Therefore, the weaning practice relies mostly on small case series, local practice patterns, and case reports, and the existing knowledge, as well as the partially differing recommendations which are based mainly on expert opinions, need to be periodically systematised. Addressing these shortcomings, our review aims to summarize the evidence and expert opinion on the evaluation of cardiac recovery during mechanical ventricular support by paying special attention to the reliability of the methods and parameters used for assessment of myocardial recovery and the challenges met in both evaluation of recovery and weaning decision making.

Heart failure etiology and risk of right heart failure in adult left ventricular assist device support: the European Registry for Patients with Mechanical Circulatory Support (EUROMACS)

Objectives: Development of right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation remains a leading cause of perioperative morbidity, end-organ dysfunction and mortality. The objective of this study was to investigate whether the etiology of HF (ischemic HF versus non-ischemic HF) affects the risk of RVF within admission for LVAD implantation and during long-term follow-up. Methods: Between January 2011 and June 27, 2018, 3536 patients were prospectively enrolled into EUROMACS registry. Adult patients (>18 years) who received a first time LVAD were included. When excluding patients with congenital, restrictive, hypertrophic, valvular cardiomyopathies, and myocarditis the total population consisted of 2404 patients. Results: The total cohort consists of 2404 patients. Mean age were 55 years and predominantly male sex [2024 (84.2%)]. At the time of LVAD implantation 1355 (56.4%) patients had ischemic HF and 1049 (43.6%) patients had non-ischemic HF. The incidence of RVF was significantly increased in the non-ischemic HF group in the adjusted model (p = .026). The relative risk difference for RVF in patients with non-ischemic HF was in the adjusted model increased by an absolute value of 5.1% (95% CI: 0.61-9.6). In the ischemic HF group 76 patients (13.4%) developed late RVF and 62 patients (14.8%) in the non-ischemic HF group (p = .56). No differences in occurrence of RVF between HF etiology was observed after 2 and 4 years of follow-up, respectively (crude: p = .25, adjusted (sex and age) p = .2 and crude: p = .59, adjusted (sex and age) p = .44). Conclusions: Patients with non-ischemic HF undergoing LVAD had an increased incidence of early RVF compared to patients with ischemic HF in a large European population. During follow-up after discharge 14% patients developed RVF. We recommend HF etiology to be considered in identifying patients who are at risk for postoperative RVF after LVAD implantation.

The Total Artificial Heart: Where Are We?

The total artificial heart (TAH) is a device that replaces the failing ventricles. There have been numerous TAHs designed over the last few decades, but the one with the largest patient experience is the SynCardia temporary TAH. The 50-mL and 70-mL sizes have been approved in the United States, Europe, and Canada as a bridge to transplantation. It is indicated in patients with severe biventricular failure or structural heart issues that preclude the use of a left ventricular assist device. The majority of the patients implanted are Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2. The 1-year survival in experienced centers that have implanted over 10 TAHs is 73%. The risk factors for death include older age, need for preimplantation dialysis, and malnutrition. The most common causes of death are multiple organ failure, usually the result of physiologic deterioration before implantation, and neurologic dysfunction. The device allows the patient to be discharged home and managed as an outpatient. Proper patient selection, the timing of intervention, patient care, and device management are essential for a suitable outcome. In addition, the CARMAT TAH is another device that will soon be studied in a clinical trial in the United States. The BiVACOR TAH is a revolutionary design utilizing electromagnetic levitation that is expected to enter a clinical trial in the next few years.

Temporary left ventricular assist devices as a bridge to heart transplantation

BACKGROUND

To create equitable access to donor organs for the highest mortality patients, the cardiac transplant allocation system now prioritizes patients with surgically implanted temporary left ventricular assist devices (T-LVADs). The outcomes following a direct bridge from a T-LVAD to orthotopic heart transplant (OHT) are not well delineated.

AIM

This study investigates the T-LVAD waitlist outcomes and compares the posttransplant outcomes in patients bridged to OHT with surgically implanted T-LVADs to patients bridged with durable continuous-flow left ventricular assist devices (CF-LVADs).

METHODS

Adults recorded in the United Network for Organ Sharing registry bridged to OHT with a durable CF-LVAD and T-LVADs, with or without temporary right ventricular assist devices (T-RVADs), between 2010 and 2018 were included. Propensity matching and multivariable Cox regression were utilized to compare outcomes.

RESULTS

Of 504 patients waitlisted with T-LVADs, the majority were transplanted (50%), bridged to CF-LVAD (17%), or recovered (9%). A total of 9047 recipients were bridged to OHT during the study period with 8875 CF-LVADs and 172 T-LVADs. Early survival in propensity-matched T-LVAD ± T-RVAD patients was similar to CF-LVAD ± T-RVAD patients but reduced at a 1-year follow-up. This difference in survival at 1-year follow-up was attributable to significantly reduced survival in patients with combined T-LVAD + T-RVAD support when compared with CF-LVAD, isolated T-LVAD and combined CF-LVAD + T-RVAD support (80% vs 90% vs 90% vs 91%; P = .005).

CONCLUSIONS

This study demonstrates that most patients waitlisted with a T-LVAD are successfully bridged to durable therapy or recover, and those bridged to OHT have acceptable posttransplant outcomes, particularly when T-RVADs are not required.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Mechanical circulatory support for the right ventricle in combination with a left ventricular assist device

Introduction: Right heart failure (RHF) in patients with a left ventricular assist device (LVAD) carries a poor prognosis although the treatment strategy including mechanical circulatory support for the failing right ventricle (RV) has not been well established. Areas covered: In this review, we describe an overview of RHF post-LVAD implant including natural history, prevalence, pathophysiology, outcomes, and challenges to predict RHF post-LVAD implant. Then, we focus on right ventricular assist devices (RVADs) and their clinical outcomes. Recently developed percutaneous RVADs are the major advance in this field. Finally, we discuss future perspectives to overcome limitations of the current treatment options. Expert opinion: In the absence of dedicated RVAD system RHF post-LVAD implant may have been undertreated. Now that dedicated percutaneous RVADs have emerged, surgeons are encouraged to use these new devices to improve outcomes of LVAD therapy. As experience accumulates, we should be able to establish the best possible strategy to treat early RHF post-LVAD implant. Late RHF is another form of RHF post-LVAD implant and has been underappreciated. Further research is mandatory to clarify the mechanism and risk factors. There are still unmet needs for a dedicated implantable RVAD for a subset of patients who need long-term RV support.

Temporary support strategies for cardiogenic shock: extracorporeal membrane oxygenation, percutaneous ventricular assist devices and surgically placed extracorporeal ventricular assist devices

The majority of clinical pathways and paradigms utilized in the treatment and management of cardiogenic shock with temporary mechanical circulatory support (MCS) are largely based on individual physician intuition and ad hoc problem-solving. Substantial mortality gains in the acute myocardial infarction cardiogenic shock (AMI-CS) population were observed with the reported outcomes of the SHOCK trial in 1999 compared to previous populations with AMI-CS. Nonetheless even in the age of percutaneous coronary intervention (PCI) of the infarct related artery, survival rates continue to be only approximately 50%. The conventional focus since the SHOCK trial has centered on revascularization strategies and the subsequent medical management of these patients post-PCI with ever diminishing returns. Perhaps we have hit the "glass ceiling" with current strategies and it is time to explore novel strategies to salvage not only the heart but more importantly the patient and potentially more of both. Going forward, researchers need to focus on developing a systematic approach to problem solving in utilizing MCS for patients with cardiogenic shock. Effective methodologies that are evidence based will help physicians in their decision-making when considering temporary MCS for patients.

Temporary assist device support for the right ventricle: pre-implant and post-implant challenges

Severe right ventricular (RV) failure is more likely reversible than similar magnitudes of left ventricular (LV) failure and, because reversal of both adaptive remodeling and impaired contractility require most often only short periods of support, the use of temporary RV assist devices (t-RVADs) can be a life-saving therapy option for many patients. Although increased experience with t-RVADs and progresses made in the development of safer devices with lower risk for complications has improved both recovery rate of RV function and patient survival, the mortality of t-RVAD recipients can still be high but it depends mainly on the primary cause of RV failure (RVF), the severity of end-organ dysfunction, and the timing of RVAD implantation, and much less on adverse events and complications related to RVAD implantation, support, or removal. Reduced survival of RVAD recipients should therefore not discourage appropriate application of RVADs because their underuse further reduces the chances for RV recovery and patient survival. The article reviews and discusses the challenges related to the pre-implant and post-implant decision-making processes aiming to get best possible therapeutic results. Special attention is focused on pre-implant RV assessment and prediction of RV improvement during mechanical unloading, patient selection for t-RVAD therapy, assessment of unloading-promoted RV recovery, and prediction of its stability after RVAD removal. Particular consideration is also given to prediction of RVF after LVAD implantation which is usually hampered by the complex interactions between the different risk factors related indirectly or directly to the RV potential for reverse remodeling and functional recovery.

Outcomes After Extracorporeal Right Ventricular Assist Device Combined With Durable Left Ventricular Assist Device Support

BACKGROUND

Right heart failure occurs in 9% to 44% of left ventricular assist device (LVAD) implants, of which less than 10% require right ventricular assist device (RVAD) support either concurrently with the LVAD or staged, as a delayed procedure. We have reported our outcomes based on whether the RVAD was placed concurrently or staged.

METHODS

Clinical data were obtained from the Duke University Medical Center database. The study focused on all consecutive adult patients who received continuous flow LVAD with either concurrent or staged (within 7 days) extracorporeal, temporary RVAD, between October 2007 and October 2017. Adverse event profiles and ability to wean from RVAD were compared between these two groups.

RESULTS

Overall, 43 patients required an extracorporeal RVAD; 67% (n = 29) were implanted concurrently and 33% (n = 14) were implanted as staged after the LVAD. In all, 67% of patients (n = 29) could be weaned to an isolated LVAD. The 30-day, inhospital, and total mortality rates for our cohort were 14%, 28%, and 51% respectively. The mortality rate in the study period for the staged implants was 71% versus 45% for the concurrent implants (p = 0.101). In addition, staged RVAD implantation carried a significantly higher rate of postoperative renal failure (64% versus 28%, p = 0.044).

CONCLUSIONS

There was a low incidence of need for RVAD in our cohort. The majority could be weaned to an isolated LVAD. Morbidity and mortality rates of this mode of biventricular support remain high. Early institution of RVAD support was associated with reduced rates of post-LVAD renal failure rates.

Evaluation of Cardiac Recovery in Ventricular Assist Device Recipients: Particularities, Reliability, and Practical Challenges

In carefully selected patients with ventricular assist devices (VADs), good long-term results after device weaning and explantation can be achieved when reverse remodelling and improvement of native cardiac function occur. Monitoring of cardiac size, geometry, and function after initial VAD implantation is necessary to identify such patients. Formal guidelines for recovery assessment in patients with VADs do not exist, and protocols for recovery assessment and criteria for device weaning and explantation vary among centres. Barriers to evaluation of cardiac recovery include technical problems in obtaining echo images in patients with VADs, time restrictions for necessary VAD reductions/interruptions during assessment, and regurgitant flow patterns that occur with interruption of continuous flow VADs. The few larger studies addressing cardiac recovery after VAD implantation employed varied study designs, limiting interpretation. Current clinical practice is guided largely by local practice patterns, case reports, and small case series, and the available body of research-consisting mostly of expert opinions-has not been systematically addressed. This summary reviews evidence and expert opinion on VAD-promoted cardiac recovery assessment, its reliability, and associated challenges.

Utilization and Outcomes of Temporary Mechanical Circulatory Support for Graft Dysfunction After Heart Transplantation

Graft dysfunction is the main cause of early mortality after heart transplantation. In cases of severe graft dysfunction, temporary mechanical circulatory support (TMCS) may be necessary. The aim of this systematic review was to examine the utilization and outcomes of TMCS in patients with graft dysfunction after heart transplantation. Electronic search was performed to identify all studies in the English literature assessing the use of TMCS for graft dysfunction. All identified articles were systematically assessed for inclusion and exclusion criteria. Of the 5,462 studies identified, 41 studies were included. Among the 11,555 patients undergoing heart transplantation, 695 (6.0%) required TMCS with patients most often supported using venoarterial extracorporeal membrane oxygenation (79.4%) followed by right ventricular assist devices (11.1%), biventricular assist devices (BiVADs) (7.5%), and left ventricular assist devices (LVADs) (2.0%). Patients supported by LVADs were more likely to be supported longer (p = 0.003), have a higher death by cardiac event (p = 0.013) and retransplantation rate (p = 0.015). In contrast, patients supported with BiVAD and LVAD were more likely to be weaned off support (p = 0.020). Overall, no significant difference was found in pooled 30 day survival (p = 0.31), survival to discharge (p = 0.19), and overall survival (p = 0.51) between the subgroups. Temporary mechanical circulatory support is an effective modality to support patients with graft dysfunction after heart transplantation. Further studies are needed to establish the optimal threshold and strategy for TMCS and to augment cardiac recovery and long-term survival.

The neutrophil to lymphocyte ratio in patients supported with extracorporeal membrane oxygenation

INTRODUCTION

The neutrophil to lymphocyte ratio (NLR) has proven to be a robust predictor of mortality in a wide range of cardiovascular diseases. This study investigated the predictive value of the NLR in patients supported by extracorporeal membrane oxygenation (ECMO) systems.

METHODS

This study included 107 patients who underwent ECMO implantation for cardiogenic shock. Median preoperative NLR was used to divide the cohort, with Group 1 NLR <14.2 and Group 2 with NLR ≥14.2. Survival, the primary outcome, was compared between groups.

RESULTS

The study cohort was composed of 64 (60%) males with an average age 53.1 ± 14.9 years. Patients in Group 1 had an average NLR of 7.5 ± 3.5 compared to 27.1 ± 19.9 in Group 2. Additionally, those in Group 2 had significantly higher preoperative blood urea nitrogen (BUN) and age. Survival analysis indicated a thirty-day survival of 56.2%, with significantly worsened mortality in patients with NLR greater than 14.2, p=0.047.

DISCUSSION

Our study shows the NLR has prognostic value in patients undergoing ECMO implantation. Leukocytes are known contributors to myocardial damage and neutrophil infiltration is associated with damage caused by myocardial ischemia.

Pulmonary Arterial Compliance Improves Rapidly After Left Ventricular Assist Device Implantation

Pulmonary artery compliance (PAC) contributes to right ventricular (RV) afterload, is decreased in the setting of increased left ventricular (LV) filling pressures, and may be an important component of World Health Organization (WHO) group II pulmonary hypertension (PH). Left ventricular assist device (LVAD) implantation can rapidly change LV filling, but its relationship with PAC is unknown. Right heart catheterization was performed preoperatively, postoperatively (between 48 and 72 hours), and >30 days post-LVAD implantation in a cohort of 64 patients with end-stage systolic heart failure. Within 72 hours, LVAD implantation was associated with an increase in PAC (2.0-3.7 ml/mm Hg, p < 0.0001), a decrease in pulmonary vascular resistance (3.5-1.7 Wood units, p < 0.0001). Pulmonary arterial compliance did not increase further at the >30 post-LVAD time point (3.7 ± 1.7 to 3.6 ± 0.44 ml/mm Hg, p = 0.44). Pulmonary artery compliance improves rapidly after LVAD implantation. This suggests that more permanent changes in the pulmonary vascular bed may not be responsible for the abnormal PAC observed in WHO group II PH.

Cardiac passive-aggressive behavior? The right ventricle in patients with a left ventricular assist device

INTRODUCTION

Right ventricular failure (RVF) affects up to 50% of patients post-left ventricular assist device (LVAD) implantation, and carries significant morbidity and mortality. There is no widely-used long-term mechanical support option for the right ventricle, thus early identification, prevention and medical treatment of RVF is of the upmost importance. Areas covered: A PubMed search was first completed searching 'Right ventricular failure post-LVAD' which yielded 152 results, and a subsequent search was performed under 'RV mechanical support' which yielded 374 results, and was filtered to 'humans' and literature written in English, generating 219 results. We focused this research on pre-operative risk factors identified in the literature for developing RVF-post LVAD implantation, and the medical and surgical treatment options for RVF, including mechanical treatment options. Expert commentary: There is little consensus on pre-operative risk factors that reliably predict RVF post-LVAD implantation. Large prospective randomized trials would help clarify indications for specific medical and surgical therapy. We gather this knowledge in the present article and describe the main RVF remediation modalities. Surgeons and anesthesiologists should help prevent and have a low threshold for initiating supportive treatment for RVF, which may include increasingly invasive therapies up to long-term mechanical RV support.

Minimally invasive approach for percutaneous CentriMag right ventricular assist device support using a single PROTEKDuo Cannula

Background

Right ventricular failure is a serious complication after left ventricular assist device placement.

Case Presentation

A 70-year-old male in decompensated heart failure with right ventricular failure after the placement of a left ventricular assist device. A single dual-lumen PROTEKDuo cannula was inserted percutaneously via the internal jugular vein to draw blood from the right atrium and return into the pulmonary artery using the CentriMag system, by passing the failing ventricle. The patient was successfully weaned from right ventricular assist device.

Conclusions

In comparison to two-cannula conventional procedures, this right ventrivular assist device system improves patient rehabilitation and minimizes blood loss and risk of infection, while shortening procedure time and improving clinical outcomes in right ventricular failure.

Costs and Outcomes in the Care of Bi-ventricular Support as a Bridge to Cardiac Transplant

Bi-ventricular (Bi-V) mechanical circulatory support is commonly used as a bridge to cardiac transplant. However, the optimal strategy is unknown. We examined the outcomes, as well as the costs in the use of Bi-V support as a bridge to cardiac transplant. From 2001 to 2014, three different Bi-V support strategies were utilized: 1) Para-corporeal ventricular assist device (PVAD-2001-2006), 2) Heartmate II left ventricular assist device in conjunction with a temporary CentriMag right ventricular assist device (HMII + CMAG-2006-2012), and the total artificial heart (TAH-2012-2014). Total costs were derived from the hospitalization at implant, and postimplant costs defined as equipment and re-hospitalizations before transplantation. Sixty-five (34 PVADs, 20 HMII + CMAG, and 11 TAHs) devices were used as a bridge for transplant. There were no differences in implant variables including age, INTERMACS score, or implant length of stay. Although the wait list mortality was not different between groups (PVAD-32%, HMII + CMAG-45%, TAH-54%; p = 0.3), the percentage of patients transplanted were highest in the PVAD group: (PVAD-55.8%, HMII + CMAG-30.0%, TAH-18.2%; p = 0.01). Total costs were not significantly different between groups (PVAD-$306,166 ± 247,839, HMII + CMAG-$278,958 ± 135,324, TAH-$321,387 ± 21,2477; p = 0.5). Despite variations in therapy, outcomes and costs for patients requiring Bi-V support as a bridge to cardiac transplant have remained constant.

Right Ventricular Assist Device Configuration for Remote Decannulation

Preoperative risk factors, intraoperative fluid shifts, and transfusions place patients at increased risk for right ventricular failure during left ventricular assist device implantation. Despite aggressive use of inotropes and pulmonary vasodilators, in severe cases of RV failure, a right ventricular assist device may be required. For the past several years, we have been implanting right ventricular assist devices in the presented configuration, allowing less invasive removal without sternotomy. The method is presented herein.

Long-term total cardiac support in a Fontan-type circulation with HeartMate II left ventricular assist device

Interest in utilizing long-term mechanical circulatory support for Fontan-type circulation has been high. Unfortunately, so far such attempts have not been successful. Herein, we are presenting the first case of an individual with biventricular heart failure and Fontan-type circulation on long-term mechanical circulatory support with a continuous-flow left ventricular assist device.

Use of Heart Failure Medical Therapies Among Patients With Left Ventricular Assist Devices: Insights From INTERMACS

BACKGROUND

Use of left ventricular assist devices (LVADs) for treatment of advanced heart failure has expanded significantly over the past decade. However, concomitant use of heart failure medical therapies after implant is poorly characterized.

METHODS AND RESULTS

We examined the use of heart failure medications before and after LVAD implant in adult patients enrolled in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) between 2008 and 2013 (N = 9359). Using logistic regression, we examined relationships between patient characteristics and medication use at 3 months after implant. Baseline rates of heart failure therapies before implant were 38% for angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), 55% for β-blockers, 40% for mineralocorticoid receptor antagonists (MRAs), 87% for loop diuretics, 54% for amiodarone, 11% for phosphodiesterase inhibitors, 22% for warfarin, and 54% for antiplatelet agents. By 3 months after implant, the rates were 50% for ACE inhibitors or ARBs, 68% for β-blockers, 33% for MRAs, 68% for loop diuretics, 42% for amiodarone, 21% for phosphodiesterase inhibitors, 92% for warfarin, and 84% for antiplatelet agents. In general, age, preimplant INTERMACS profile, and prior medication use were associated with medication use at 3 months.

CONCLUSIONS

Overall use of neurohormonal antagonists was low after LVAD implant, whereas use of loop diuretics and amiodarone remained high. Heart failure medication use is highly variable, but appears to generally increase after LVAD implantation. Low neurohormonal antagonist use may reflect practice uncertainty in the clinical utility of these medications post-LVAD.

Right atrial pressure/pulmonary artery wedge pressure ratio: A more specific predictor of survival in pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease. Current prognostic models are not ideal, and identifying more accurate prognostic variables is needed. The objective of this study was to evaluate the relative prognostic value of the right atrial pressure/pulmonary artery wedge pressure (RAP/PAWP) ratio in PAH patients. We hypothesized that the RAP/PAWP ratio is more predictive of survival than any of the other measured or calculated hemodynamic variables.

METHODS

We performed a secondary analysis of a PAH cohort (Cohort 1) and validated our results in a separate cohort (Cohort 2). Cohort 1 included primarily patients enrolled in prospective, short-term, randomized clinical trials and subsequently followed long term. Cohort 2 included patients prospectively enrolled in a PAH registry at a tertiary PAH referral center.

RESULTS

Cohort 1 (n = 847) and Cohort 2 (n = 697) had a mean age of 47 and 54 years, respectively. Most were female (78% and 73%, respectively), Caucasian (83% and 82%), with advanced functional class disease status (New York Heart Association Functional Class III/IV 85% and 68%) and with significantly elevated hemodynamics (mean RAP/PAWP ratio: 1.2 and 1.0; pulmonary vascular resistance: 13.5 and 9.4 Wood units). RAP/PAWP ratio indicated a 1-year hazard ratio of 1.44 (p = 0.0001) and 1.35, respectively (p < 0.0001), and was the most consistently predictive hemodynamic variable across the 2 cohorts. These results remain valid even when adjusted for other covariables in multivariable regression models.

CONCLUSIONS

The RAP/PAWP ratio is a more specific predictor of survival than any other hemodynamic variable, and we recommend that it be used in clinical prognostication and PAH predictive models.

Left ventricular assist device management and complications

Patients on long-term left ventricular assist device (LVAD) support present unique challenges in the intensive care unit. It is crucial to know the status of end-organ perfusion, which may require invasive hemodynamic monitoring with a systemic arterial and pulmonary artery catheter. Depending on the indication for LVAD support (bridge to decision or cardiac transplantation vs destination therapy), it is important to readdress goals of care with the patient (if possible) and their family after major events have occurred that challenge the survival of the patient.

Survival on biventricular mechanical support with the Centrimag® as a bridge to decision: a single-center risk stratification

Objective:

Temporary mechanical assist devices are increasingly being used as a lifesaving bridge to decision in patients requiring cardiopulmonary resuscitation. We report our single-center experience with biventricular Centrimag® pumps over a five-year period.

Method:

Data was retrospectively collected in consecutive patients who required biventricular support from 2008 to 2013. Patients who were supported with central cannulation using the Centrimag® system were analyzed. In addition to demographic information, data pertaining to indications, outcomes and mortality were collected.

Results:

The cohort consisted of 48 patients (19 women and 29 men, mean age of 56 years). The median duration of support was 14 days. The median duration to patient expiration while still on the Centrimag® was 12 days. Thirty-day survival was 56% (27/48). Nine patients were explanted to recovery, while fourteen patients were converted to a durable LVAD, two of whom were then transplanted. We stratified patients into two groups. Group I comprised patients who were either explanted to recovery, converted to durable LVAD or transplanted (23/48) and Group II consisted of patients who either died on the Centrimag® or were explanted for withdrawal of care (25/48). Statistical analysis did not reveal any clinically significant differences between the two groups in terms of age, sex, etiology, hemodynamic, co-morbidities or laboratory parameters.

Conclusion:

The biventricular Centrimag® can be used as a bridge to decision in patients with thirty-day survival of >50%. Parameters to predict 30-day survival in this high-risk cohort continue to remain elusive.

Evolving strategies in the treatment of acute myocardial infarction-induced cardiogenic shock

Despite advances in medical technology and re-vascularization interventions, the mortality rate for cardiogenic shock (CS) following acute myocardial infarction has remained at 50%. The majority of these mortalities are from left ventricular failure resulting in multi-system organ dysfunction. The field of mechanical circulatory support (MCS) has evolved within the past decade, with improved outcomes from extracorporeal membrane oxygenation as well as continuous-flow left ventricular assist devices (CF LVADs). In this paper, we discuss our institutional treatment strategies, the rationale for the protocol development, and our improved outcomes when using MCS in patients with refractory CS following acute myocardial infarction.

Machines versus medication for biventricular heart failure: focus on the total artificial heart

ABSTRACT 

The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

Current status of extracorporeal ventricular assist devices in Japan

Extracorporeal VADs are less expensive, their prices reimbursable by the health insurance being about one-sixth of those of implantable VADs in Japan. However, a disadvantage is that, in Japan, their use is restricted to hospitals, necessitating prolonged hospitalization, reducing the patients' quality of life. According to the Japanese registry for Mechanically Assisted Circulatory Support, the survival rate does not differ significantly between patients with extracorporeal and implantable VADs. As in Europe and North America, extracorporeal VADs in Japan are commonly used as Bridge to Decision or Bridge to Recovery. Extracorporeal VADs are switched to implantable VADs as a Bridge-to-Bridge strategy after stabilization or when cardiac function recovery fails. They are also used as right ventricular assist devices (RVADs) in patients with right heart failure. A special characteristic of extracorporeal VADs in Japan is their frequent use as a Bridge to Candidacy. In Japan, indications for implantable VADs are restricted to patients registered for heart transplantation. Therefore, in patients who cannot be registered for transplantation because of transient renal dysfunction, etc., due to heart failure, extracorporeal VADs are used first, and then replaced by implantable VADs after transplant registry is done. Here, we describe the current status of extracorporeal VADs in Japan, focusing on the environmental backgrounds, along with a review of the relevant literature.

Mesenchymal precursor cells as adjunctive therapy in recipients of contemporary left ventricular assist devices

BACKGROUND

Allogeneic mesenchymal precursor cells (MPCs) injected during left ventricular assist device (LVAD) implantation may contribute to myocardial recovery. This trial explores the safety and efficacy of this strategy.

METHODS AND RESULTS

In this multicenter, double-blind, sham-procedure controlled trial, 30 patients were randomized (2:1) to intramyocardial injection of 25 million MPCs or medium during LVAD implantation. The primary safety end point was incidence of infectious myocarditis, myocardial rupture, neoplasm, hypersensitivity reaction, and immune sensitization (90 days after randomization). Key efficacy end points were functional status and ventricular function while temporarily weaned from LVAD support (90 days after randomization). Patients were followed up until transplant or 12 months after randomization, whichever came first. Mean age was 57.4 (±13.6) years, mean left ventricular ejection fraction was 18.1%, and 66.7% were destination therapy LVADs. No safety events were observed. Successful temporary LVAD weaning was achieved in 50% of MPC and 20% of control patients at 90 days (P=0.24); the posterior probability that MPCs increased the likelihood of successful weaning was 93%. At 90 days, 3 deaths (30%) occurred in control patients, and none occurred in MPC patients. Mean left ventricular ejection fraction after successful wean was 24.0% (MPC=10) and 22.5% (control=2; P=0.56). At 12 months, 30% of MPC patients and 40% of control patients were successfully temporarily weaned from LVAD support (P=0.69), and 6 deaths (30%) occurred in MPC patients. Donor-specific HLA sensitization developed in 2 MPC and 3 control patients and resolved by 12 months.

CONCLUSIONS

In this preliminary trial, administration of MPCs appeared to be safe, and there was a potential signal of efficacy. Future studies will evaluate the potential for higher or additional doses to enhance the ability to wean LVAD recipients off support.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01442129.