Ventricular Assist Device Research Articles

TCT-580 CFD-Based Performance Prediction and Comprehensive Evaluation of a Newly Development Percutaneous Ventricular Assist Device

TCT-580 CFD-Based Performance Prediction and Comprehensive Evaluation of a Newly Development Percutaneous Ventricular Assist Device

SINGLE-CENTER EXPERIENCE OF HEART TRANSPLANTATION AT THE HEART CENTER OF ASTANA

Background. Chronic heart failure is a major global health issue. As a complication of most cardiovascular diseases, it affects 4% of the population. Heart transplantation is the gold standard in the treatment of patients with end-stage heart failure. Objective of the study was to evaluate early and long-term outcomes of heart transplants performed at the Heart Center University Medical Center (Heart Center) over a 10-year period. Materials and methods. Cross-sectional study was conducted from 2012 to 2022, 86 orthotopic heart transplants were performed at the Heart Center. The analysis of the obtained results was conducted retrospectively. Results. From August 2012 to December 2022, 114 patients were on the waiting list for heart transplantation. Of these, 86 (75.4%) patients underwent transplantation; 10 (8.7%) patients were excluded. Among the 86 patients, 49 (56.9%) had previously undergone cardiac surgery. Of these, 42 (48.8%) had a left ventricular assist device implanted earlier, 3 (3.4%) had a fully artificial heart, and 2 (2.5%) were on temporary mechanical support (central veno-arterial Extracorporeal membrane oxygenation). Hospital mortality was 8 (9.3%) recipients. In 2.7% of cases, the cause of death was an acute cerebrovascular accident on the second day post-surgery. Postoperative renal dysfunction was noted in 28 (32.5%) patients. An analysis of all performed heart transplantation cases showed a 30-day survival rate of 94%, a 1-year survival rate of 84.3%, and a 5-year survival rate of 64.7%. Conclusion. In the hospital period and the first 6 months after heart transplantation, infectious-septic complications were predominant, whereas in later periods, rejection reactions were more common.

Polymeric artificial heart valves derived from modified diol-based polycarbonate polyurethanes

A series of polycarbonate silicone polyurethanes (SiPCUs) have been synthesized to develop elastomers with the mechanical properties, biostability, and biocompatibility required for artificial heart valve manufacturing. In these SiPCUs, the polar functional group 4,4′-dicyclohexylmethane diisocyanate (HMDI) was incorporated into the soft segment 1,6-poly (hexamethylene carbonate) diol (PCDL) to form the modified macromolecular diol, PCDL-HMDI-PCDL. The hard segment consisted of HMDI and the chain extenders 1,4-butanediol and 1,3-bis(4-hydroxybutyl)-1,1,3,3-tetramethyl disiloxane (BHTD). The synthesized PHC-PCUB improves the excessive microphase separation caused by the introduction of PDMS. This material possesses good physicochemical properties, long-term oxidative degradation stability, and comparatively low mechanical performance loss after degradation. Compared to the commercially available bioprosthetic heart valve (BHV) material Glut-PP, PHC-PCUB demonstrated enhanced biocompatibility, good thromboresistant properties, less calcification, and higher endothelial cell adhesion. Furthermore, valve prototypes fabricated with PHC-PCUB showed improved hemodynamic performance under various simulated conditions, highlighting the potential of PHC-PCUB as an advanced material for valve leaflets. Statement of SignificanceArtificial heart valves are crucial for treating valve diseases, and polyurethane-based valves present a promising alternative due to their durability, strong biocompatibility, and customizable properties. This study improves the biostability and post-degradation mechanical properties of siloxane polyurethanes by reducing the content of polydimethylsiloxane (PDMS) and adding modified diol (PCDL-HMDI-PCDL). By integrating hexamethylene diisocyanate (HMDI) and chain extenders, we developed polycarbonate siloxane polyurethanes (SiPCUs) that improve phase mixing, mechanical strength, and oxidative stability. These SiPCUs also exhibit good thromboresistance and calcification resistance, low cytotoxicity, and promote cell adhesion, positioning them as highly promising materials for heart valve leaflets, effectively addressing the limitations of current mechanical and bioprosthetic valves.

Nine Years of Continuous Flow LVAD (HeartMate 3): Survival and LVAD-Related Complications before and after Hospital Discharge.

End-stage heart failure is associated with high mortality. Recent developments such as the left ventricular assist device (LVAD) have improved patient outcomes. The HeartMate 3 LVAD is a novel centrifugal pump that was developed to provide hemodynamic support in heart failure patients, either as a bridge-to-transplant (BTT), myocardial recovery, or destination therapy (DT). Our objective was to evaluate the survival rates and LVAD-related complications of the HeartMate 3 LVAD before and after hospital discharge in our center. We retrospectively reviewed all patients implanted with the HeartMate 3 LVAD in our institute between September 2015 and June 2024. Patients who received a Heart Ware Ventricular Assist Device (HVAD) and HeartMate 2 LVAD devices were excluded. The primary endpoint was survival before and after hospital discharge. The secondary endpoints included an incidence of serious LVAD adverse events (bleeding, major infection, hemolysis, device thrombosis and malfunction, and neurological dysfunction) and the causes of re-admission along the follow-up period. A total of 48 consecutive HeartMate 3 LVAD patients were enrolled in this study. The mean age was 56.1 ± 10.6 years. A total of 72.9% of patients received LVAD therapy as a BTT, 14.6% as DT, 10.4% as a bridge-to-decision, and 2.1% as a bridge-to-recovery. A total of 85.4% of patients were discharged after implantation. The main cause for in-hospital mortality was right ventricular failure (8.3%), followed by stroke, abdominal bleeding, and multi-organ failure (2.1% each). One patient (2.1%) had successful heart transplantation, 26 patients (63.4%) are still on LVAD support, and 11 (26.8%) patients have died during follow-up. The main cause of mortality after hospital discharge was sepsis, which occurred in 9.8% of patients, followed by right ventricular failure, non-LVAD-related causes, unknown causes with two (4.9%) cases each, and one case of fatal stroke (2.4%). During the follow-up, there was no need for LVAD replacement. HeartMate 3 LVAD is associated with excellent in-hospital survival rates in patients with end-stage heart failure. Right ventricular failure was the main cause of death before hospital discharge, whereas sepsis was the main cause of death after hospital discharge.

Aortic regurgitation in left ventricular assist device patients - Does aortic root dilatation contribute to valve incompetence?

Aortic regurgitation (AR) is a known complication after left ventricular assist device (LVAD) implantation potentially leading to recurrent heart failure. Possible pathomechanisms include valvular pathologies and aortic root dilatation. We assessed aortic root dimensions in a group of consecutive LVAD patients who received HeartMate 3. Since 11/2015, we identified 68 patients with no or mild AR at the time of HeartMate 3 implantation who underwent serial echocardiography to assess AR and aortic root dimensions (annulus, sinus, and sinotubular junction). Median follow-up was 40 months (2-94 months). Results were correlated with clinical outcomes. Patients were 60 ± 10 years old, predominantly male (88%) and 35% presented in preoperative critical condition as defined by INTERMACS levels 1 and 2. During follow-up, 23 patients developed AR ≥ II (34%). Actuarial incidence was 8% at 1 year, 29% at 3 years and 41% at 5 years. Echocardiography revealed practically stable root dimensions at the latest follow-up compared to the preoperative state (annulus: 23 ± 3 mm vs. 23 ± 2 mm, sinus: 32 ± 4 mm vs. 33 ± 3 mm, sinotubular junction: 27 ± 3 mm vs. 28 ± 3 mm), irrespective of the development of AR. Serial CT angiograms were performed in 13 patients to confirm echocardiographic findings. Twenty-one patients died during LVAD support leading to a 5-year survival of 71%, showing no difference between patients with and without AR ≥ II (p = 0.573). At least moderate AR develops over time in a substantial fraction of patients (one-third over 3 years). The mechanism does not seem to be related to dilatation of the aortic annulus or root.

The Ventricular Assist Device team in the management of patients treated with long-term Mechanical Circulatory Support

The number of people with heart failure is increasing rapidly worldwide. Despite preventive measures, optimal medical therapy, and cardiac transplantation, the overall morbidity and mortality of this syndrome remain high. Ventricular assist devices are well established as a treatment for heart failure and are increasingly used globally, both for destination therapy and as a bridge to cardiac transplantation. The management of these patients requires the training of a highly specialized team to ensure optimal outcomes. This article focuses on implementing a multidisciplinary team on the ventricular assist device, ensuring comprehensive care for implanted patients to mitigate potential complications early.

Total Artificial Heart Implantation as a Bridge to Transplantation in Slovakia.

Although left ventricular assist device implantation represents the majority of durable mechanical circulatory support implants for patients with advanced heart failure, as many as 20 to 30% will subsequently have right heart failure requiring extended inotropic support or short-term mechanical circulatory support, and the total artificial heart is an established tool in the bridge to transplant armamentarium. The aim of this short report is to present our center's experience with the use of SynCardia total artificial heart. Between November 2017 and April 2021, 10 SynCardia total artificial heart devices were implanted. Of the 10 patients who underwent total artificial heart implantation, 6 (60%) were successfully bridged to transplant with a median time of 6.5 (interquartile range [IQR] 6-8) months, and 4 patients died on device support during the index hospitalization. The 30-day, 1-year, and 3-year survival rates after heart transplantation were the same at 66.7% (4/6). Despite the uncertain future of total artificial hearts, it remains a viable option for patients who require biventricular bridge to transplant or for a select subset of patients with advance heart failure who may not otherwise survive.

The Right Ventricular-Arterial Compliance Index: A Novel Hemodynamic Marker to Predict Right Heart Failure Following Left Ventricular Assist Device.

The development of right heart failure (RHF) in patients with advanced heart failure following left ventricular assist device (LVAD) implantation remains difficult to predict. We proposed a novel composite hemodynamic index-the right ventricular-arterial compliance index (RVACi), derived from pulmonary artery pulse pressure (PAPP), ejection time (ET), heart rate (HR), and cardiac output (CO), with and expressed as mm Hg·s/L. We then conducted a retrospective, single-center analysis comparing the predictive value of RVACi for the development of RHF or unplanned right ventricular (RV) mechanical circulatory support following LVAD implantation against existing hemodynamic indices. One hundred patients were enrolled after screening 232 patients over a 10 year period, with 74 patients having complete hemodynamic data for RVACi calculation. There was good correlation between pulmonary arterial capacitance (R² = 0.48) and pulmonary vascular resistance (R² = 0.63) with RVACi, but not RV stroke work index or pulmonary artery pulsatility index. Reduced baseline RVACi (52 ± 23 vs. 92 ± 55 mm Hg·s/L; p = 0.02) was the strongest hemodynamic predictor of unplanned RV mechanical circulatory support requirement in patients following LVAD insertion. Composite pulsatile hemodynamic indices including RVACi may provide additional insight over existing hemodynamic indices for the prediction of RHF and need for RV mechanical circulatory support.

Five-Year Outcomes in Patients Implanted With a HeartMate 3 Left Ventricular Assist Device at a High-Volume Center.

Five-Year Outcomes in Patients Implanted With a HeartMate 3 Left Ventricular Assist Device at a High-Volume Center.

ACTION-ARC Pediatric and Adult Congenital Heart Disease Ventricular Assist Device Adverse Event Definitions-2023.

Adverse events (AEs) experienced by children and adults with congenital heart disease (CHD) on ventricular assist devices (VADs) are sometimes unique to these populations. The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) and the Academic Research Consortium (ARC) aimed to harmonize definitions of pediatric and CHD AEs for use in clinical trials, registries, and regulatory evaluation. Data from the ACTION registry and adjudication committee were used to adapt general mechanical circulatory support ARC definitions. This ACTION-ARC international expert panel of trialists, clinicians, patients, families, statisticians, biomedical engineers, device developers, and regulatory agencies drafted and iterated definitions harmonized to ACTION data and existing literature during sessions conducted between December 2022 and May 2023, followed by dissemination across clinical/research audiences and professional organizations and further revision. Both email-linked, internet-based surveys and in-person discussions were used as a modified Delphi process. Nineteen AE types were identified and defined, including seven new event types and six event types that were deleted and will no longer be collected, achieving consensus. ACTION-ARC paired rigorous development with methodical stakeholder involvement and dissemination to define pediatric VAD AEs to facilitate assimilation of data across future clinical trials and evaluation of devices for VAD-supported children and adults with CHD.

Accelerated Wean: A Novel 3 Day Berlin Heart Protocol in a Pediatric Patient.

We present the case of a 4 year old child who developed cardiogenic shock due to permanent junctional reciprocating tachycardia, requiring left ventricular assist device (LVAD) support. Despite the initial critical clinical presentation, successful myocardial recovery was achieved over 5 months, allowing for successful LVAD explantation. The patient's young age and behavioral issues were constraining factors for a prolonged LVAD wean trial. A modified wean protocol over a 3 day period with parameters for assessment of cardiac recovery before LVAD explantation is described.

Clinical Outcomes of Left Ventricular Assist Device Bleeding Complication.

Bleeding complications have emerged as major causes of morbidity and mortality in patients with implantable left ventricular assist devices (LVAD). We hypothesized that the hemodynamics after LVAD implantation may influence the occurrence of bleeding complications after LVAD implantation. We retrospectively evaluated 78 patients who underwent continuous-flow LVAD implantation and hemodynamic ramp test after LVAD implantation between July 2017 and July 2023 at Osaka University. The bleeding complication occurred in 13 patients. The rates of freedom from bleeding complications at 1, 3, and 5 years were 94%, 85%, and 74%. Gastrointestinal bleeding, nose bleeding, and intraperitoneal hemorrhage occurred in six, three, and two patients, respectively. Preoperative average brachial-ankle pulse wave velocity (baPWV) was positively associated with bleeding complication (1,276 ± 280 vs. 1,098 ± 190 cm/s p = 0.04). In the hemodynamic ramp test, systemic vascular resistance (SVR) in patients with bleeding complications was higher than that in patients without bleeding complications (SVR: 1,359 ± 341 vs. 1,150 ± 217 dyne sec/cm5, p = 0.01). High preoperative baPWV and high SVR in the hemodynamic ramp test were significantly associated with bleeding complications after LVAD implantation. Arteriosclerosis is a risk factor for bleeding complications after LVAD implantation.

Outcomes of Intracorporeal Continuous and Paracorporeal Pulsatile Ventricular Assist Devices in Pediatric Patients 10-30 kg: Erratum.

Outcomes of Intracorporeal Continuous and Paracorporeal Pulsatile Ventricular Assist Devices in Pediatric Patients 10-30 kg: Erratum.

A review of polymeric heart valves leaflet geometric configuration and structural optimization

Valvular heart disease (VHD) is a major cause of loss of physical function, quality of life and longevity, and its prevalence is growing worldwide due to increased survival rates and an aging population. The most common treatment for VHD is surgical heart valve replacement with mechanical heart valves (MHVs) and bioprosthetic heart valves (BHVs), but with different limitations. Polymeric heart valves (PHVs) exhibit promising material properties, valve dynamics and biocompatibility, representing the most feasible alternative to existing artificial heart valves. However, inadequate fatigue performance remains a critical obstacle to their clinical translation. In this case, geometry and material design are essential to obtain the best mechanical properties of the PHV. In this study, we summarized the effects of optimal design of PHVs from geometrical configuration optimization (valve height, thickness and design curve) and structural material optimization (anisotropy, fiber reinforcement, variable thickness, microstructure and asymmetric optimization), and selected the parameters including Effective Orifice Area (EOA), Regurgitant fraction (RF), and Stress Distribution to compare the performance of valves. It would provide the theoretical support for the optimal design of PHVs.

The Association Between Pulmonary Vascular Resistance and Posttransplant Outcomes Differs by Left Ventricular Assist Device Status.

Elevated pulmonary vascular resistance (PVR) is a risk factor for mortality after heart transplantation (HT), but whether this association differs for patients with and without left ventricular assist device (LVAD) support before HT is unknown. We analyzed adult first-time HT recipients from the United Network for Organ Sharing (UNOS) registry transplanted between 2010 and 2021. We quantified the association between PVR and the outcomes of 30 day graft failure and 1 year mortality using multivariable logistic regression, stratified by LVAD support status at the time of HT. Pulmonary vascular resistance was modeled using restricted cubic splines to identify clinically relevant risk thresholds. We also examined the association with 10 year survival using multivariable Cox proportional hazards regression. For PVR values less than approximately 2 WU, higher PVR was independently associated with a higher risk of early graft failure (odds ratio [OR] = 1.58, 95% CI: 1.06-2.36) and a higher risk of 1 year mortality (OR = 1.32, 95% CI: 1.10-1.59) among LVAD patients only (interaction p = 0.023 and 0.03, respectively). However, for patients surviving at least 1 year, PVR was not associated with long-term mortality among either subgroup. Whether more aggressive reduction of PVR among HT candidates supported with LVADs can mitigate these risks requires further study.

Exercise training in left ventricular assist device patients: Protocol of an individual participant data meta-analysis.

Although left ventricular assist device (LVAD) implantation improves prognosis of advanced heart failure patients still suffer from impaired exercise capacity and quality of life (QoL). Exercise training may improve both; however, the available evidence about exercise training effects in LVAD patients remains inconclusive due to small and monocentric randomized controlled trials. This study aims to aggregate the individual participant data (IPD) to perform meta-analysis on the safety and efficacy of exercise training on exercise capacity and QoL over standard care in LVAD patients. Randomized controlled trials comparing exercise training and standard care (no supervised training) will be identified through database searching. Corresponding authors of eligible randomized controlled trials will be invited to share IPD. All IPD will be checked, recalculated to validate findings in initial reports, merged in a single dataset and stored in a secured encrypted database server. The merged IPD will be screened for quality, risk of bias, and heterogeneity of the included trials. Random effects meta-analyses will be conducted using one-stage and two-stage approaches, in particular with a view to subgroup analyses. Based on findings of the individual randomized trials, we expected to obtain superior effects of exercise training on submaximal exercise capacity and QoL and similar effects on maximal aerobic capacity when compared with standard care. Our study will be the first to harmonize IPD in meta-analysis to demonstrate the effects of exercise training on exercise performance and QoL over standard care in LVAD patients. CRD42023480119.

Innovations in Imaging: 18F-Fluorodeoxyglucose PET/CT for Assessment of Cardiovascular Infection and Inflammation.

18F-Fluorodeoxyglucose positron emission tomography (PET) combined with computed tomography (CT), referred to as 18F-FDG PET/CT, plays a significant role in the diagnosis and management of patients with systemic infectious and inflammatory conditions. This review provides an overview of 18F-FDG PET/CT in systemic infectious and inflammatory conditions, including infective endocarditis (IE), cardiac implantable electrical device (CIED)/left ventricular assist device (LVAD) infection, sarcoidosis, and large-vessel vasculitis (LVV). This review highlights the past and present literature in the increasing role of 18F-FDG PET/CT in cardiovascular inflammation and infection, including diagnostic and prognostic findings. They key aspects of this paper are to highlight the importance of 18F-FDG PET/CT in cardiovascular infection and inflammation, and to provide illustrations of how it can contribute to patient diagnosis and management.

Ratio of pulmonary artery diameter to ascending aortic diameter and its association with right ventricular failure after left ventricular assist device implantation

BackgroundSeveral invasive hemodynamic parameters help predict right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation. However, prediction using non-invasive parameters alone has not been established. The ratio of the diameters of the pulmonary artery (PAD) to those of the ascending aorta (AoD) may indicate past hemodynamic load and cardiac dysfunction. We aimed to investigate a predictive model for RVF after LVAD implantation using non-invasive parameters including PAD/AoD ratio. MethodsWe studied 141 patients who underwent primary LVAD implantation and 117 healthy individuals with computed tomography (CT) data. RVF was defined as the need for a subsequent right ventricular assist device or intravenous inotrope administration for more than 30 days after LVAD implantation. The PAD/AoD ratio was measured at the level of the pulmonary artery bifurcation on the CT transaxial slices. ResultsRVF was observed in 29 patients. The correlation between PAD and AoD differed among healthy individuals, patients with and without RVF. Patients with RVF had higher total bilirubin and log brain natriuretic peptide (BNP) levels, a lower left ventricular end-diastolic diameter (LVDd) index, and a higher PAD/AoD ratio than those without RVF. Decision tree analysis indicated that the subgroup with a high PAD/AoD ratio (≥1.09) and a small LVDd index (<35.4 mm/m2) showed the highest probability of RVF (100 %), while the subgroup with a low PAD/AoD ratio (<1.09) and low log BNP (<2.79) showed the lowest probability of RVF (1 %). ConclusionCombining non-invasive parameters with the PAD/AoD ratio can predict RVF with high accuracy.

Multicenter exploration of specialist palliative care in patients with left ventricular assist devices – a retrospective study

BackgroundThe number of advanced heart failure patients with left ventricular assist devices (LVAD) is increasing. Despite guideline-recommendations, little is known about specialist palliative care involvement in LVAD-patients, especially in Europe. This study aims to investigate timing and setting of specialist palliative care in LVAD-patients.MethodsWe conducted a retrospective multicenter study in 2022. Specialist palliative care services in German LVAD-centers were identified and invited to participate. Forty adult LVAD-patients (mean age 65 years (SD 7.9), 90% male) from seven centers that received a specialist palliative care consultation during hospitalization were included.ResultsIn 37 (67.3%) of the 55 LVAD-centers, specialist palliative care was available. The median duration between LVAD-implantation and first specialist palliative care contact was 17 months (IQR 6.3–50.3 months). Median duration between consultation and death was seven days (IQR 3–28 days). 65% of consults took place in an intensive/intermediate care unit with half of the patients having a Do-Not-Resuscitate order. Care planning significantly increased during involvement (advance directives before: n = 15, after: n = 19, p < 0.001; DNR before: n = 20, after: n = 28, p < 0.001). Symptom burden as assessed at first specialist palliative care contact was higher compared to the consultation requests (request: median 3 symptoms (IQR 3–6); first contact: median 9 (IQR 6–10); p < 0.001) with a focus on weakness, anxiety, overburdening of next-of-kin and dyspnea. More than 70% of patients died during index hospitalization, one third of these in a palliative care unit.ConclusionsThis largest European multicenter investigation of LVAD-patients receiving specialist palliative care shows a late integration and high physical and psychosocial symptom burden. This study highlights the urgent need for earlier integration to identify and address poorly controlled symptoms. Further studies and educational efforts are needed to close the gap between guideline-recommendations and the current status quo.

Assessment of haemolysis models for a positive-displacement total artificial heart.

The assessment and reduction of haemolysis within mechanical circulatory support (MCS) remains a concern with regard to device safety and regulatory approval. Numerical methods for predicting haemolysis have typically been applied to rotary MCS devices and the extent to which these methods apply to positive-displacement MCS is unclear. The aim of this study was to evaluate the suitability of these methods for assessing haemolysis in positive-displacement blood pumps. Eulerian scalar-transport and Lagrangian particle-tracking approaches derived from the shear-based power-law relationship were used to calculate haemolysis in a computational fluid dynamics model of the Realheart total artificial heart. A range of power-law constants and their effect on simulated haemolysis were also investigated. Both Eulerian and Lagrangian methods identified the same key mechanism of haemolysis: leakage flow through the bileaflet valves. Whilst the magnitude of haemolysis varied with different power-law constants, the method of haemolysis generation remained consistent. The Eulerian method was more robust and reliable at identifying sites of haemolysis generation, as it was able to capture the persistent leakage flow throughout the entire pumping cycle. This study paves the way for different positive-displacement MCS devices to be compared across different operating conditions, enabling the optimisation of these pumps for improved patient outcomes.