De Novo Aortic Regurgitation After Continuous-Flow Left Ventricular Assist Device Implantation

Preoperative higher right ventricular stroke work index increases the risk of de novo aortic insufficiency after continuous-flow left ventricular assist device implantation

During continuous-flow left ventricular assist device (CF-LVAD) support, hemodynamic shear stress causes a burden on aortic valve (AV) leaflets, leading to de novo aortic insufficiency (AI). This study investigated the influence of preoperative hemodynamic parameters on de novo AI in CF-LVAD recipients. We reviewed 125 patients who underwent CF-LVAD implantation without concomitant AV surgery between 2005 and 2018. De novo AI was defined as moderate or severe AI in those with none or trivial preoperative AI. During mean 30 ± 16 months of CF-LVAD support, de novo AI-free rate was 86% and 67% at 1 and 2 years, respectively. Multivariable analysis showed that higher right ventricular stroke work index (RVSWI) (hazard ratio, 1.12 /g/m2/beat; 95% confidence interval, 1.00-1.20; p = 0.047) and trivial grade AI (hazard ratio, 2.8; 95% confidence interval, 1.2-6.4; p = 0.020) were independent preoperative risk factors for de novo AI. The longitudinal analysis using generalized mixed effects model showed that higher RVSWI was associated with continuous AV closure after LVAD implantation (Odd ratio, 1.20/g/m2/beat; 95% confidence interval, 1.00-1.43 /g/m2/beat; p = 0.047). Right heart catheterization revealed that preoperative RVSWI was positively correlated with postoperative pump flow index in patients with continuously closed AV (r = 0.44, p = 0.04, n = 22). Preoperative higher RVSWI was a significant risk factor for de novo AI following CF-LVAD implantation. In patients with preserved right ventricular function, postoperative higher pump flow may affect AI development via hemodynamic stress on the AV.

Aortic Root Thrombosis in patients with HeartMate 3 left ventricular assist device support

BACKGROUND

Aortic root thrombosis(ART) is a complication of continuous-flow left ventricular assist device therapy. However, the incidence and related complications of ART in HeartMate 3 (HM3) patients remain unknown.

METHODS

Patients who underwent HM3 implantation from November 2014 to August 2020 at a quaternary academic medical center were included. Demographics and outcomes were abstracted from the medical record. Echocardiograms and contrast-enhanced computed tomography studies were reviewed to identify patients who developed ART and/or moderate or greater aortic insufficiency (AI) on HM3 support.

RESULTS

The study cohort included 197 HM3 patients with a median postimplant follow-up of 17.5 months. Nineteen patients (9.6%) developed ART during HM3 support, and 15 patients (7.6%) developed moderate or greater AI. Baseline age, gender, race, implantation strategy, and INTERMACS classification were similar between the ART and no-ART groups. ART was associated with an increased risk of death, stroke, or aortic valve (AV) intervention (subhazard ratio [SHR] 3.60 [95% confidence interval (CI) 1.71-7.56]; p = 0.001) and moderate or greater AI (SHR 11.1 [CI 3.60-34.1]; p < 0.001) but was not associated with a statistically significantly increased risk of death or stroke on HM3 support (2.12 [0.86-5.22]; p = 0.10). Of the 19 patients with ART, 6 (31.6%) developed moderate or greater AI, necessitating more frequent AV interventions (ART: 5 AV interventions [3 surgical repairs, 1 surgical replacement, 1 transcatheter replacement; 26.3%]; no-ART: 0).

CONCLUSIONS

Nearly 10% of HM3 patients developed ART during device support. ART was associated with increased risk of a composite end-point of death, stroke, or AV intervention as well as moderate or greater AI.

Real-time regurgitation estimation in percutaneous left ventricular assist device fully supported condition using an unscented Kalman filter

Objective.Significant aortic regurgitation is a common complication following left ventricular assist device (LVAD) intervention, and existing studies have not attempted to monitor regurgitation signals and undertake preventive measures during full support. Regurgitation is an adverse event that can lead to inadequate left ventricular unloading, insufficient peripheral perfusion, and repeated episodes of heart failure. Moreover, regurgitation occurring during full support due to pump position offset cannot be directly controlled through control algorithms. Therefore, accurate estimation of regurgitation during percutaneous left ventricular assist device (PLVAD) full support is critical for clinical management and patient safety.Approach.An estimation system based on the regurgitation model is built in this paper, and the unscented Kalman filter estimator (UKF) is introduced as an estimation approach. Three offset degrees and three heart failure states are considered in the investigation. Using the mock circulatory loop experimental platform, compare the regurgitation estimated by the UKF algorithm with the actual measured regurgitation; the errors are analyzed using standard confidence intervals of ±2 SDs, and the effectiveness of the mentioned algorithms is thus assessed. The generalization ability of the proposed algorithm is verified by setting different heart failure conditions and different rotational speeds. The root mean square error and correlation coefficient between the estimated and actual values are quantified and the statistical significance of accuracy differences in estimation is illustrated using one-way analysis of variance (One-Way ANOVA), which in turn assessed the accuracy and stability of the UKF algorithm.Main results.The research findings demonstrate that the regurgitation estimation system based on the regurgitation model and UKF can relatively accurately estimate the regurgitation status of patients during PLVAD full support, but the effect of myocardial contractility on the estimation accuracy still needs to be taken into account.Significance.The proposed estimation method in this study provides essential reference information for clinical practitioners, enabling them to promptly manage potential complications arising from regurgitation. By sensitively detecting LVAD adverse events, valuable insights into the performance and reliability of the LVAD device can be obtained, offering crucial feedback and data support for device improvement and optimization.

Transcatheter management of pure native aortic valve regurgitation in patients with left ventricular assist device

OBJECTIVES

Aortic valve regurgitation (AR) frequently complicates the clinical course after left ventricular assist device (LVAD) implantation. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement (SAVR) in this cohort with a mostly high surgical risk profile. The unique challenges in LVAD patients, such as presence of non-calcified aortic valves and annular dilatation, raise concerns about device migration and paravalvular leakage (PVL) leading to missing device success. This study evaluates procedural outcomes and survival rates in LVAD patients who underwent TAVI, emphasizing strategies to enhance device success.

METHODS

Between January 2017 and April 2023, 27 LVAD patients with clinically significant AR underwent elective or urgent TAVI at our centre. Primary end-points were procedural success rates, without the need for a second transcatheter heart valve (THV) and postprocedural AR/PVL. Secondary outcomes included survival rates and adverse events.

RESULTS

Among the cohort, 14.8% received AR-dedicated TAVI devices, with none requiring a second THV. There was no intraprocedural AR, and 1 patient (25%) had AR > 'trace' at discharge. Additionally, 25.9% underwent device landing zone (DLZ) pre-stenting with a standard TAVI device, all without needing a second THV. There was no intraprocedural AR, and none to trace AR at discharge. Among the 59.3% receiving standard TAVI devices, 37.5% required a second THV. In this subgroup, intraprocedural AR > 'trace' occurred in 12.5%, decreasing to 6.25% at discharge. In-hospital mortality was 3.7%, and median follow-up survival was 388 days (interquartile range 208-1167 days).

CONCLUSIONS

TAVI yields promising procedural outcomes and early survival rates in LVAD patients with AR. Tailored TAVI devices and pre-stenting techniques enhance procedural success. Continued research into these strategies is essential to optimize outcomes in this complex patient cohort.

Regurgitation during the fully supported condition of the percutaneous left ventricular assist device

Objective.A percutaneous left ventricular assist device (PLVAD) can be used as a bridge to heart transplantation or as a temporary support for end-stage heart failure. Transvalvularly placed PLVADs may result in aortic regurgitation due to unstable pump position during fully supported operation, which may diminish the pumping effect of forward flow and predispose to complications. Therefore, accurate characterization of aortic regurgitation is essential for proper modeling of heart-pump interactions and validation of control strategies.Approach.In the present study, an improved aortic valve model was used to analyze the severity of regurgitation produced by different pump position offsets. The link between pump position offset degree and regurgitation is validated in the fixed speed mode, and the influence of pump speed on regurgitation is verified in the variable speed mode, using the mock circulatory loop (MCL) experimental platform.Main results.The greater the pump offset and the more severe the regurgitation, the more carefully the pump speed needs to be managed. To avoid over-pumping, the recommended pump speed in this study should not exceed 30 000 rpm.Significance.The modeling approach provide in this study not only makes it easier to comprehend the impact of regurgitation events on the entire interactive system during mechanical assistance, but it also aids in providing timely alerts and suitable management measures.

Patient-specific, echocardiography compatible flow loop model of aortic valve regurgitation in the setting of a mechanical assist device

Background

Aortic regurgitation (AR) occurs commonly in patients with continuous-flow left ventricular assist devices (LVAD). No gold standard is available to assess AR severity in this setting. Aim of this study was to create a patient-specific model of AR-LVAD with tailored AR flow assessed by Doppler echocardiography.

Methods

An echo-compatible flow loop incorporating a 3D printed left heart of a Heart Mate II (HMII) recipient with known significant AR was created. Forward flow and LVAD flow at different LVAD speed were directly measured and AR regurgitant volume (RegVol) obtained by subtraction. Doppler parameters of AR were simultaneously measured at each LVAD speed.

Results

We reproduced hemodynamics in a LVAD recipient with AR. AR in the model replicated accurately the AR in the index patient by comparable Color Doppler assessment. Forward flow increased from 4.09 to 5.61 L/min with LVAD speed increasing from 8,800 to 11,000 RPM while RegVol increased by 0.5 L/min (2.01 to 2.5 L/min).

Conclusions

Our circulatory flow loop was able to accurately replicate AR severity and flow hemodynamics in an LVAD recipient. This model can be reliably used to study echo parameters and aid clinical management of patients with LVAD.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

Key questions about aortic insufficiency in patients with durable left ventricular assist devices

The development of the latest generation of durable left ventricular assist devices (LVAD) drastically decreased adverse events such as pump thrombosis or disabling strokes. However, time-related complications such as aortic insufficiency (AI) continue to impair outcomes following durable LVAD implantation, especially in the context of long-term therapy. Up to one-quarter of patients with durable LVAD develop moderate or severe AI at 1 year and its incidence increases with the duration of support. The continuous regurgitant flow within the left ventricle can compromise left ventricular unloading, increase filling pressures, decrease forward flow and can thus lead to organ hypoperfusion and heart failure. This review aims to give an overview of the epidemiology, pathophysiology, and clinical consequences of AI in patients with durable LVAD.

Concomitant or late aortic valve intervention and its efficacy for aortic insufficiency associated with continuous-flow left ventricular assist device implantation

Moderate to severe aortic insufficiency (AI) in patients who underwent continuous-flow left ventricular assist device (CF-LVAD) implantation is a significant complication. According to the INTERMACS registry analysis, at least mild AI occurs in 55% of patients at 6 months after CF-LVAD implantation and moderate to severe AI is significantly associated with higher rates of re-hospitalization and mortality. The clinical implications of these data may underscore consideration of prophylactic aortic valve replacement, or repair, at the time of CF-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AI that is more than mild. More crucially, even if a native aortic valve is seemingly competent at the time of VAD implantation, we frequently find de novo AI as time goes by, potentially due to commissural fusion in the setting of inconsistent aortic valve opening or persistent valve closure caused by CF-LVAD support, that alters morphological and functional properties of innately competent aortic valves. Therefore, close monitoring of AI is mandatory, as the prognostic nature of its longitudinal progression is still unclear. Clearly, significant AI during VAD support warrants surgical intervention at the appropriate timing, especially in patients of destination therapy. Nonetheless, such an uncertainty in the progression of AI translates to a lack of consensus regarding the management of this untoward complication. In practice, proposed surgical options are aortic valve replacement, repair, closure, and more recently transcatheter aortic valve implantation or closure. Transcatheter approach is of course less invasive, however, its efficacy in terms of long-term outcome is limited. In this review, we summarize the recent evidence related to the pathophysiology and surgical treatment of AI associated with CF-LVAD implantation.

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.

Pathophysiology and management of valvular disease in patients with destination left ventricular assist devices

Over the last two decades, implantable continuous flow left ventricular assist devices (LVAD) have proven to be invaluable tools for the management of selected advanced heart failure patients, improving patient longevity and quality of life. The presence of concomitant valvular pathology, including that involving the tricuspid, mitral, and aortic valve, has important implications relating to the decision to move forward with LVAD implantation. Furthermore, the presence of concomitant valvular pathology often influences the surgical strategy for LVAD implantation. Concomitant valve repair or replacement is not uncommonly required in such circumstances, which increases surgical complexity and has demonstrated prognostic implications both short and longer term following LVAD implantation. Beyond the index operation, it is also well established that certain valvular pathologies may develop or worsen over time following LVAD support. The presence of pre-existing valvular pathology or that which develops following LVAD implant is of particular importance to the destination therapy LVAD patient population. As these patients are not expected to have the opportunity for heart transplantation in the future, optimization of LVAD support including ameliorating valvular disease is critical for the maximization of patient longevity and quality of life. As collective experience has grown over time, the ability of clinicians to effectively address concomitant valvular pathology in LVAD patients has improved in the pre-implant, implant, and post-implant phase, through both medical management and procedural optimization. Nevertheless, there remains uncertainty over many facets of concomitant valvular pathology in advanced heart failure patients, and the understanding of how to best approach these conditions in the LVAD patient population continues to evolve. Herein, we present a comprehensive review of the current state of the field relating to the pathophysiology and management of valvular disease in destination LVAD patients.

Impact of progressive aortic regurgitation on outcomes after left ventricular assist device implantation

Aortic regurgitation (AR) following continuous flow left ventricular assist device implantation (cf-LVAD) may adversely impact outcomes. We aimed to assess the incidence and impact of progressive AR after cf-LVAD on prognosis, biomarkers, functional capacity and echocardiographic findings. In an analysis of the PCHF-VAD database encompassing 12 European heart failure centers, patients were dichotomized according to the progression of AR following LVAD implantation. Patients with de-novo AR or AR progression (AR_1) were compared to patients without worsening AR (AR_0). Among 396 patients (mean age 53 ± 12 years, 82% male), 153 (39%) experienced progression of AR over a median of 1.4 years on LVAD support. Before LVAD implantation, AR_1 patients were less frequently diabetic, had lower body mass indices and higher baseline NT-proBNP values. Progressive AR did not adversely impact mortality (26% in both groups, HR 0.91 [95% CI 0.61-1.36]; P = 0.65). No intergroup variability was observed in NT-proBNP values and 6-minute walk test results at index hospitalization discharge and at 6-month follow-up. However, AR_1 patients were more likely to remain in NYHA class III and had worse right ventricular function at 6-month follow-up. Lack of aortic valve opening was related to de-novo or worsening AR (P < 0.001), irrespective of systolic blood pressure (P = 0.67). Patients commonly experience de-novo or worsening AR when exposed to continuous flow of contemporary LVADs. While reducing effective forward flow, worsening AR did not influence survival. However, less complete functional recovery and worse RV performance among AR_1 patients were observed. Lack of aortic valve opening was associated with progressive AR.

HFA of the ESC position paper on the management of LVAD-supported patients for the non-LVAD specialist healthcare provider Part 3: at the hospital and discharge

The growing population of left ventricular assist device (LVAD)‐supported patients increases the probability of an LVAD‐ supported patient hospitalized in the internal or surgical wards with certain expected device related, and patient‐device interaction complication as well as with any other comorbidities requiring hospitalization. In this third part of the trilogy on the management of LVAD‐supported patients for the non‐LVAD specialist healthcare provider, definitions and structured approach to the hospitalized LVAD‐supported patient are presented including blood pressure assessment, medical therapy of the LVAD supported patient, and challenges related to anaesthesia and non‐cardiac surgical interventions. Finally, important aspects to consider when discharging an LVAD patient home and palliative and end‐of‐life approaches are described.

Predictors and Long-Term Impact of De Novo Aortic Regurgitation in Continuous Flow Left Ventricular Assist Devices Using Vena Contracta

The aim of this study was to identify the optimal echocardiographic measurement of aortic regurgitation (AR) in continuous flow left ventricular assist devices (LVAD) and determine risk factors and clinical implications of de novo AR. Echocardiographic images from consecutive patients who underwent LVAD implantation from February 2007 to March 2017 were reviewed. Severity of de novo AR was determined by vena contracta (VC). Preimplant clinical characteristics, LVAD settings at discharge, and outcomes including heart failure hospitalizations, all-cause mortality, and ventricular arrhythmias of patients with greater than or equal to moderate de novo AR were compared with those with mild or no AR. Among 219 patients, greater than or equal to moderate de novo AR occurred in 65 (29.7%). Left ventricular assist devices support duration was longer with greater than or equal to moderate AR than no or mild AR. In multivariable analysis, preimplant trivial AR and persistent aortic valve (AV) closure were independently associated with de novo AR. By time-varying covariate analysis, survival and freedom from cardiovascular events in greater than or equal to moderate AR were significantly worse (hazard ratio [HR] = 3.947, p < 0.001 and HR = 4.666, p < 0.001). In conclusion, de novo greater than or equal to moderate AR measured by VC increases risk of adverse events. Longer LVAD support duration, preimplant trivial AR, and a closed AV are associated with occurrence of greater than or equal to moderate de novo AR.

Prediction of aortic valve regurgitation after continuous-flow left ventricular assist device implantation using artificial intelligence trained on acoustic spectra

Significant aortic regurgitation (AR) is a common complication after continuous-flow left ventricular assist device (LVAD) implantation. Using machine-learning algorithms, this study was designed to examine valuable predictors obtained from LVAD sound and to provide models for identifying AR. During a 2-year follow-up period of 13 patients with Jarvik2000 LVAD, sound signals were serially obtained from the chest wall above the LVAD using an electronic stethoscope for 1 min at 40,000 Hz, and echocardiography was simultaneously performed to confirm the presence of AR. Among the 245 echocardiographic and acoustic data collected, we found 26 episodes of significant AR, which we categorized as “present”; the other 219 episodes were characterized as “none”. Wavelet (time–frequency) analysis was applied to the LVAD sound and 19 feature vectors of instantaneous spectral components were extracted. Important variables for predicting AR were searched using an iterative forward selection method. Seventy-five percent of 245 episodes were randomly assigned as training data and the remaining as test data. Supervised machine learning for predicting concomitant AR involved an ensemble classifier and tenfold stratified cross-validation. Of the 19 features, the most useful variables for predicting concomitant AR were the amplitude of the first harmonic, LVAD rotational speed during intermittent low speed (ILS), and the variation in the amplitude during normal rotation and ILS. The predictive accuracy and area under the curve were 91% and 0.73, respectively. Machine learning, trained on the time–frequency acoustic spectra, provides a novel modality for detecting concomitant AR during follow-up after LVAD.

Treatment With Impella Increases the Risk of De Novo Aortic Insufficiency Post Left Ventricular Assist Device Implant

BACKGROUND

Impella (Abiomed Inc, Danvers, MA) is a temporary mechanical support device positioned across the aortic valve, and can be used to support patient before LVAD implantation. There are no data on the incidence of aortic insufficiency (AI) in patients supported with Impella as a bridge to durable LVAD implantation. We sought to assess the incidence of AI in patients with Impella support as a bridge to durable left ventricular assist device (LVAD) implantation.

METHODS

We reviewed all patients undergoing primary LVAD implantation at the University of Pennsylvania from January 2015 onward, comparing those supported with Impella as temporary mechanical support with those supported by either venoarterial extracorporeal life support or an intra-aortic balloon pump. We reviewed transthoracic echocardiography preoperatively, as well as at 1 week, 1, 3, 6, 9, and 12 months after LVAD implantation.

RESULTS

A total of 215 echocardiograms were analyzed in 41 patients. Eleven patients were supported with Impella before LVAD implant-6 patients with Impella alone (5 with Impella CP, 1 with Impella 5.0) and 5 with Impella in conjunction with venoarterial extracorporeal life support (2 with Impella 2.5, 2 with Impella CP, and 1 with Impella 5.0). After LVAD implant, mild or moderate AI developed in 82% of patients supported with Impella (9 of 11) compared with 43% of those without Impella (13 of 30) (P = .038).

CONCLUSIONS

Patients supported by Impella as a bridge to durable LVAD have a higher risk of developing AI. Further studies are needed to assess this risk as the use of the Impella increases.

Use of patient-specific computational models for optimization of aortic insufficiency after implantation of left ventricular assist device

OBJECTIVE

Aortic incompetence (AI) is observed to be accelerated in the continuous-flow left ventricular assist device (LVAD) population and is related to increased mortality. Using computational fluid dynamics (CFD), we investigated the hemodynamic conditions related to the orientation of the LVAD outflow in these patients.

METHOD

We identified 10 patients with new aortic regurgitation, and 20 who did not, after LVAD implantation between 2009 and 2018. Three-dimensional models of patients' aortas were created from their computed tomography scans. The geometry of the LVAD outflow graft in relation to the aorta was quantified using azimuth angles (AA), polar angles (PAs), and distance from aortic root. The models were used to run CFD simulations, which calculated the pressures and wall shear stress (rWSS) exerted on the aortic root.

RESULTS

The AA and PA were found to be similar. However, for combinations of high values of AA and low values of PA, there were no patients with AI. The distance from aortic root to the outflow graft was also smaller in patients who developed AI (3.39 ± 0.7 vs 4.07 ± 0.77 cm, P = .04). There was no significant difference in aortic root pressures in the 2 groups. The rWSS was greater in AI patients (4.60 ± 5.70 vs 2.37 ± 1.20 dyne/cm², P < .001). Qualitatively, we observed a trend of greater perturbations, regions of high rWSS, and flow eddies in the AI group.

CONCLUSIONS

Using CFD simulations, we demonstrated that patients who developed de novo AI have greater rWSS at the aortic root, and their outflow grafts were placed closer to the aortic roots than those patients without de novo AI.

Transcatheter aortic valve replacement thrombosis in patient supported with durable left ventricular assist device

Aortic insufficiency (AI) is a frequent problem after continuous-flow left ventricular assist device (LVAD) implantation and results in increased morbidity and mortality. Advances in transcatheter aortic valve replacement (TAVR) technology have resulted in this being discussed as a potential option for LVAD patients with AI. While small case series have been published, we report the first case of TAVR thrombosis in an LVAD patient. This case highlights a major diagnostic and management dilemma that should become more present if this strategy becomes more widespread.

Continuous-Flow Left Ventricular Assist Devices and Valvular Heart Disease: A Comprehensive Review

Mechanical circulatory support with implantable durable continuous-flow left ventricular assist devices (CF-LVADs) represents an established surgical treatment option for patients with advanced heart failure refractory to guideline-directed medical therapy. CF-LVAD therapy has been demonstrated to offer significant survival, functional, and quality-of-life benefits. However, nearly one-half of patients with advanced heart failure undergoing implantation of a CF-LVAD have important valvular heart disease (VHD) present at the time of device implantation or develop VHD during support that can lead to worsening right or left ventricular dysfunction and result in development of recurrent heart failure, more frequent adverse events, and higher mortality. In this review, we summarize the recent evidence related to the pathophysiology and treatment of VHD in the setting of CF-LAVD support and include a review of the specific valve pathologies of aortic insufficiency (AI), mitral regurgitation (MR), and tricuspid regurgitation (TR). Recent data demonstrate an increasing appreciation and understanding of how VHD may adversely affect the hemodynamic benefits of CF-LVAD support. This is particularly relevant for MR, where increasing evidence now demonstrates that persistent MR after CF-LVAD implantation can contribute to worsening right heart failure and recurrent heart failure symptoms. Standard surgical interventions and novel percutaneous approaches for treatment of VHD in the setting of CF-LVAD support, such as transcatheter aortic valve replacement or transcatheter mitral valve repair, are available, and indications to intervene for VHD in the setting of CF-LVAD support continue to evolve.

Hemodynamic effects of support modes of LVADs on the aortic valve

As the alternative treatment for heart failure, left ventricular assist devices (LVADs) have been widely applied to clinical practice. However, the effects of the support modes of LVADs on the biomechanical states of the aortic valve are still poorly understood. Hence, the present study investigates such effects and proposes a novel fluid-structure interaction (FSI) approach that combines the lattice Boltzmann method (LBM) and finite element (FE) method. Two support modes of LVADs, namely constant speed mode and constant flow mode, which have been widely applied to clinical practice, are also designed. Results demonstrate that the support modes of LVADs could significantly affect the biomechanical states of the aortic valve and the blood flow pattern of the ascending aorta. Compared with those in the constant flow mode, the leaflets in the constant speed mode could achieve better dynamic performance and lower stress during the systolic phase. The max radial displacement of the leaflets in the constant speed mode is at 8 mm, whereas that in the constant flow mode is at 0.8 mm. Furthermore, the outflow of LVADs directly impacts the aortic surfaces of the leaflets during the diastolic phase by increasing the level of wall shear stress of the leaflets. The leaflets in the constant speed mode receive less impact than those in the constant flow mode. The condition with such minimal impact is conducive to maintaining the normal structure of leaflets and benefits the reduction of the risk of valvular diseases. In sum, the support modes of LVADs exert a crucial effect on the biomechanical environment of the aortic valve. The constant speed mode is better than the constant flow mode in terms of providing a good hemodynamic environment for the aortic valve.

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.

Practical valvular issues in patients requiring ventricular assist devices

PURPOSE OF REVIEW

As ventricular assist device (VAD) therapy in patients with advanced heart failure continues to grow, experience with concomitant valvular diseases present either before or after VAD implantation continues to accrue. In this review, we discuss recent data and current practice as it pertains to the subject of concomitant valvular disease in patients requiring VADs.

RECENT FINDINGS

Persistent aortic valve closure has been identified as a potential contributor to aortic valve 'disuse atrophy' resulting in valve degeneration. Dilation of the aortic root may be predictive of future development of aortic insufficiency. Novel echocardiographic parameters to identify the severity of aortic insufficiency following VAD implantation may be useful for risk stratification. Concomitant repair of significant mitral regurgitation may confer benefit to pulmonary vascular resistance and right ventricular function; however, this remains controversial. Concomitant repair of significant tricuspid regurgitation has not demonstrated early postoperative benefit nor survival benefit. Atrial fibrillation has emerged as a risk factor that may predict accelerated progression of postoperative tricuspid regurgitation.

SUMMARY

Management of aortic insufficiency, mitral regurgitation or tricuspid regurgitation in patients requiring VADs continues to be the source of controversy. As experience accrues with varying strategies to prevent or manage these valvular lesions, our understanding of the impact of these strategies continues to evolve.

A Comprehensive Imaging Approach to Guide the Management of Patients with Continuous-Flow Left Ventricular Assist Devices

Recent advances in mechanical circulatory support have allowed patients with end-stage heart failure to be successfully bridged to heart transplantation or live for many years on continuous-flow left ventricular assist devices (CF-LVADs) as destination therapy. As survival and quality of life continue to improve and the number of patients supported by CF-LVADs continues to grow, utilization of different imaging modalities in the care for these patients has become an integral part of many heart failure centers. We review currently available imaging modalities, with a focus on echocardiography, that aid to diagnose and manage common adverse events associated with CF-LVADs.