Use of a continuous-flow device in patients awaiting heart transplantation

Outcomes after SynCardia® temporary total artificial heart implantation: A 20-year single-center experience in 196 patients

BACKGROUND

The SynCardia® temporary total artificial heart (TAH) serves as a mechanical circulatory support device for patients suffering from irreversible biventricular failure.

METHODS

This retrospective study analyzed 196 consecutive patients who underwent TAH implantation at our center from 2001 to 2021. We assessed survival rates and all-cause mortality during TAH support, including survival post-heart transplantation.

RESULTS

The median age of patients was 55 years, with 88% being male. The primary diagnoses included cardiomyopathy (43.9%), acute myocardial infarction (26.5%), and postcardiotomy heart failure (15.5%). At implantation, 87.2% of patients were classified as INTERMACS Profile 1. The median duration of support was 96 days (IQR: 23-227). Survival rates at 1, 6, and 12 months were 72%, 41%, and 34%, respectively. Postoperative rethoracotomy was necessary in 44.4% of patients; 39.3% experienced neurological events and 24.6% developed gastrointestinal bleeding. Overall, 64.8% of patients died while on support, primarily due to multiple organ failure (55.9%). Factors such as older age, higher bilirubin levels, postcardiotomy and specific underlying diagnoses were independent predictors of mortality during TAH support. On a positive note, 35.2% of patients underwent successful heart transplants, with 1-, 5-, and 10-year posttransplant survival rates of 65%, 58%, and 51%, respectively.

CONCLUSIONS

While high mortality rates persist among patients with biventricular failure, the SynCardia® TAH offers a viable interim solution for critically ill patients, particularly those who can be successfully bridged to heart transplantation.

Clinical Outcomes of Cardiac Transplantation in Heart Failure Patients with Previous Mechanical Cardiocirculatory Support

Objectives: Heart failure (HF) remains a significant public health issue, with heart transplantation (HT) being the gold standard treatment for end-stage HF. The increasing use of mechanical circulatory support, particularly left ventricular assist devices (LVADs), as a bridge to transplant (BTT), presents new perspectives for increasingly complex clinical scenarios. This study aimed to compare long-term clinical outcomes in patients in heart failure with reduced ejection fraction (HFrEF) receiving an LVAD as BTT to those undergoing direct-to-transplant (DTT) without mechanical support, focusing on survival and post-transplant complications. Methods: A retrospective, single-center study included 105 patients who underwent HT from 2010. Patients were divided into two groups: BTT (n = 28) and DTT (n = 77). Primary endpoints included overall survival at 1 and 7 years post-HT. Secondary outcomes involved late complications, including organ rejection, renal failure, cardiac allograft vasculopathy (CAV), and cerebrovascular events. Results: At HT, the use of LVADs results in longer cardiopulmonary bypass and cross-clamping times in the BTT group; nevertheless, surgical complexity does not affect 30-day mortality. Survival at 1 year was 89.3% for BTT and 85.7% for DTT (p = 0.745), while at 7 years, it was 80.8% and 77.1%, respectively (p = 0.840). No significant differences were observed in the incidence of major complications, including permanent dialysis, organ rejection, and CAV. However, a higher incidence of cerebrovascular events was noted in the BTT group (10.7% vs. 2.6%). Conclusions: LVAD use as BTT does not negatively impact early post-transplant survival compared to DTT. At long-term follow-up, clinical outcomes remained similar across groups, supporting LVADs as a viable option for bridging patients to transplant.

Outcomes of Left Ventricular Assist Devices as Destination Therapy: A Systematic Review with Meta-Analysis

BACKGROUND

Heart failure (HF) is a chronic condition that significantly affects morbidity and mortality. For patients with end-stage HF who are not candidates for heart transplantation, left ventricular assist devices (LVADs) provide mechanical circulatory support as a long-term solution, known as destination therapy (DT).

OBJECTIVE

This meta-analysis aims to synthesize evidence on the survival rates, complications, and quality-of-life improvements associated with LVADs used as destination therapy in patients with end-stage HF.

METHODS

A systematic search of databases, including PubMed, Embase, Cochrane Library, Web of Science, and Scopus, was conducted to identify relevant studies. Studies were selected based on predefined inclusion and exclusion criteria. Data from 12 studies were extracted and analyzed using a random-effects model. Survival rates, complications (e.g., infection and bleeding), and quality-of-life measures were the primary outcomes evaluated.

RESULTS

The analysis showed significant improvements in survival, with a pooled effect size of 0.848 (95% CI: 0.306-1.390, p = 0.002). Complication rates varied, with infections and bleeding being the most common adverse events. Quality of life also improved significantly post-LVAD implantation, with a standardized mean difference of 0.78 (95% CI: 0.65-0.91).

CONCLUSIONS

LVADs as destination therapy provide a viable option for improving the survival and quality of life of end-stage HF patients, despite the associated risks of complications. Further research is needed to refine patient selection and management strategies to optimize outcomes.

Durable left ventricular assist devices: a contemporary review of their benefits and drawbacks

INTRODUCTION

Heart transplantation, the gold standard for end-stage cardiomyopathy, is hindered by donor shortages and clinical deterioration. Left ventricular assist devices (LVADs) have emerged as crucial alternatives, stabilizing hemodynamics, reversing end-organ damage, and enabling patient discharge. Significant engineering advancements and iterative improvements have since produced devices capable of rivaling heart transplantation in early survival potential. This review serves to provide an overview of LVAD technology, an understanding of current device limitations, and preview new technologies being developed to address them.

AREAS COVERED

This manuscript reviews the evolution of LVAD technology, discussing its benefits, drawbacks, and contemporary outcomes. It will detail the progression, current state, and future directions of LVAD technology, emphasizing its pivotal role in managing advanced heart failure.

EXPERT OPINION

The modern day LVAD has significantly extended the lifespan of patients with end-stage heart failure. However, adverse events remain abound and will be the focus of the next generation of devices. A burgeoning pipline of new technologies abound and preview the possibilities of a sustainable solution to a devastating disease.

Living biodrugs and how tissue source influences mesenchymal stem cell therapeutics for heart failure

In this editorial we comment on the article by Safwan M et al. We especially focused on the cardiac function restoration by the use of mesenchymal stem cells (MSCs) therapy for heart failure (HF), which has emerged as a new treatment approach as "Living Biodrugs". HF remains a significant clinical challenge due to the heart's inability to pump blood effectively, despite advancements in medical and device-based therapies. MSCs have emerged as a promising therapeutic approach, offering benefits beyond traditional treatments through their ability to modulate inflammation, reduce fibrosis, and promote endogenous tissue regeneration. MSCs can be derived from various tissues, including bone marrow and umbilical cord. Umbilical cord-derived MSCs exhibit superior expansion capabilities, making them an attractive option for HF therapy. Conversely, bone marrow-derived MSCs have been extensively studied for their potential to improve cardiac function but face challenges related to cell retention and delivery. Future research is focusing on optimizing MSC sources, enhancing differentiation and immune modulation, and improving delivery methods to overcome current limitations.

When all Else Fails, Try This: The HeartMate III Left Ventricle Assist Device

Heart failure (HF) is a progressive disease. It is estimated that more than 250,000 patients suffer from advanced HF with reduced ejection fraction refractory to medical therapy. With limited donor pool for heart transplant, continue flow left ventricle assist device (LVAD) is a lifesaving treatment option for patients with advanced HF. This review will provide an update on indications, contraindications, and associated adverse events for LVAD support with a summary of the current outcomes data.

Influence of the Outflow Graft Angular Position on the Outcomes in Patients With a Left Ventricular Assist Device

This study aimed to explore the potential impact of the angular position of the outflow graft on thromboembolic events and aortic valve regurgitation in people with a left ventricular assist device (LVAD). We analyzed contrast computed tomography (CT) data of patients with LVAD implantation between 2016 and 2021. Three-dimensional reconstructions of the outflow graft and aortic arch were performed to calculate the horizontal (azimuth) angle and vertical (polar) angle, as well as the relative distance between the outflow graft, aortic valve, and brachiocephalic artery. Among 59 patients (median age 57, 68% male), a vertical angle ≥107° correlated significantly with increased cerebrovascular accidents (hazard ratio [HR]: 5.8, 95% confidence interval [CI]: 1.3-26.3, p = 0.022) and gastrointestinal bleeding (HR: 3.4, 95% CI: 1.0-11.2, p = 0.049) during a median 25 month follow-up. No significant differences were found between the vertical angle and aortic valve regurgitation or survival. The horizontal angle and relative distance did not show differences regarding clinical adverse events. This study emphasizes the importance of the LVAD outflow graft angular position to prevent life-threatening thromboembolic events. This study suggests the need for prospective research to further validate these findings.

Multimodality imaging for the evaluation and management of patients with long-term (durable) left ventricular assist devices

Left ventricular assist devices (LVADs) are gaining increasing importance as therapeutic strategy in advanced heart failure (HF), not only as bridge to recovery or to transplant but also as destination therapy. Even though long-term LVADs are considered a precious resource to expand the treatment options and improve clinical outcome of these patients, these are limited by peri-operative and post-operative complications, such as device-related infections, haemocompatibility-related events, device mis-positioning, and right ventricular failure. For this reason, a precise pre-operative, peri-operative, and post-operative evaluation of these patients is crucial for the selection of LVAD candidates and the management LVAD recipients. The use of different imaging modalities offers important information to complete the study of patients with LVADs in each phase of their assessment, with peculiar advantages/disadvantages, ideal application, and reference parameters for each modality. This clinical consensus statement sought to guide the use of multimodality imaging for the evaluation of patients with advanced HF undergoing LVAD implantation.

Hypertrophic Cardiomyopathy: From Medical Treatment to Advanced Heart Failure Therapies

PURPOSE OF REVIEW

There has been much debate surrounding novel medical therapies and heart transplantation listing challenges in patients with hypertrophic cardiomyopathy (HCM).

RECENT FINDINGS

Recent clinical trials led to FDA approval of mavacamten (a cardiac myosin inhibitor), offering symptom relief and potentially delaying/avoiding invasive septal reduction therapies for some patients with HCM and left ventricular outflow obstruction (LVOTO). For those with refractory symptoms and end-stage heart failure, heart transplantation remains the gold standard. However, the concern for the organ allocation system failing to prioritize those individuals persists. HCM is a heterogeneous genetic condition with variable penetration and clinical presentation. Even though a large portion of patients remain asymptomatic, an important minority develops debilitating symptoms refractory to medical therapy. Post-HT short- and long-term outcomes are favorable. However, HT waitlist mortality remains high. For highly selected patients with HCM, a left ventricular assist device is a viable option.

Mortality in Recipients of Durable Left Ventricular Assist Devices Undergoing Ventricular Tachycardia Ablation

BACKGROUND

Left ventricular assist device (LVAD) recipients have a higher incidence of ventricular tachycardia (VT). However, the role of VT ablation in this population is not well-established.

OBJECTIVES

This single-center retrospective cohort study sought to examine the impact of post-LVAD implant VT ablation on survival.

METHODS

This retrospective study examined a cohort of patients that underwent LVAD implantation at Baylor St. Luke's Medical Center and Texas Heart Institute between January 2011 and January 2021. All-cause estimated mortality was compared across LVAD recipients based on the incidence of VT, timing of VT onset, and the occurrence and timing of VT ablation utilizing Kaplan-Meier survival analysis and Cox proportional hazards models.

RESULTS

Post-implant VT occurred in 53% of 575 LVAD recipients. Higher mortality was seen among patients with post-implant VT within a year of implantation (HR: 1.62 [95% CI: 1.15-2.27]). Among this cohort, patients who were treated with a catheter ablation had superior survival compared with patients treated with medical therapy alone for the 45 months following VT onset (HR: 0.48 [95% CI: 0.26-0.89]). Moreover, performance of an ablation in this population aligned mortality rates with those who did not experience post-implant VT (HR: 1.18 [95% CI: 0.71-1.98]).

CONCLUSIONS

VT occurrence within 1 year of LVAD implantation was associated with worse survival. However, performance of VT ablation in this population was correlated with improved survival compared with medical management alone. Among patients with refractory VT, catheter ablation aligned survival with other LVAD participants without post-implant VT. Catheter ablation of VT is associated with improved survival in LVAD recipients, but further prospective randomized studies are needed to compare VT ablation to medical management in LVAD recipients.

Bridge to Transplantation: Policies Impact Practices

Since the development of the first heart allocation system in 1988 to the most recent heart allocation system in 2018, the road to heart transplantation has continued to evolve. Policies were shaped with advances in temporary and durable left ventricular assist devices as well as prioritization of patients based on degree of illness. Herein, we review the changes in the heart allocation system over the past several decades and the impact of practice patterns across the United States.

Effectiveness of mechanical circulatory support devices in reversing pulmonary hypertension among heart transplant candidates: A systematic review

BACKGROUND

Pulmonary hypertension (PH) poses a significant challenge in the selection of candidates for heart transplantation, impacting their eligibility and post-transplant outcomes. Mechanical circulatory support (MCS) devices, particularly left ventricular assist devices (LVADs), have emerged as a therapeutic option to manage PH in this patient population. This systematic review aims to evaluate the effectiveness of MCS devices in reversing fixed pulmonary hypertension in heart transplant candidates.

METHODS

A comprehensive literature search was conducted across multiple databases, including PubMed, Scopus, and Web of Science, to identify studies that evaluated the effectiveness of MCS devices in reversing fixed pulmonary hypertension in heart transplant candidates. Data on pulmonary vascular resistance, PH reversal, heart transplant eligibility, and post-transplant outcomes were extracted and synthesized.

RESULTS

The review included studies that demonstrated the potential of MCS devices, especially LVADs, to significantly reduce pulmonary vascular resistance and reverse fixed pulmonary hypertension in heart transplant candidates. These findings suggest that MCS devices can improve transplant eligibility and may positively impact post-transplant survival rates. However, the literature also indicates a need for further comparative studies to optimize MCS device selection and treatment protocols.

CONCLUSION

MCS devices, particularly LVADs, play a crucial role in the management of fixed pulmonary hypertension in heart transplant candidates, improving their eligibility for transplantation and potentially enhancing post-transplant outcomes. Future research should focus on comparative effectiveness studies to guide clinical decision-making and optimize patient care in this challenging clinical scenario.

Next-Generation Cardiac Interfacing Technologies Using Nanomaterial-Based Soft Bioelectronics

Cardiac interfacing devices are essential components for the management of cardiovascular diseases, particularly in terms of electrophysiological monitoring and implementation of therapies. However, conventional cardiac devices are typically composed of rigid and bulky materials and thus pose significant challenges for effective long-term interfacing with the curvilinear surface of a dynamically beating heart. In this regard, the recent development of intrinsically soft bioelectronic devices using nanocomposites, which are fabricated by blending conductive nanofillers in polymeric and elastomeric matrices, has shown great promise. The intrinsically soft bioelectronics not only endure the dynamic beating motion of the heart and maintain stable performance but also enable conformal, reliable, and large-area interfacing with the target cardiac tissue, allowing for high-quality electrophysiological mapping, feedback electrical stimulations, and even mechanical assistance. Here, we explore next-generation cardiac interfacing strategies based on soft bioelectronic devices that utilize elastic conductive nanocomposites. We first discuss the conventional cardiac devices used to manage cardiovascular diseases and explain their undesired limitations. Then, we introduce intrinsically soft polymeric materials and mechanical restraint devices utilizing soft polymeric materials. After the discussion of the fabrication and functionalization of conductive nanomaterials, the introduction of intrinsically soft bioelectronics using nanocomposites and their application to cardiac monitoring and feedback therapy follow. Finally, comments on the future prospects of soft bioelectronics for cardiac interfacing technologies are discussed.

Special Considerations for Advanced Heart Failure Surgeries: Durable Left Ventricular Devices and Heart Transplantation

Heart transplantation and durable left ventricular assist devices (LVADs) represent two definitive therapies for end-stage heart failure in the modern era. Despite technological advances, both treatment modalities continue to experience unique risks that impact surgical and perioperative decision-making. Here, we review special populations and factors that impact risk in LVAD and heart transplant surgery and examine critical decisions in the management of these patients. As both heart transplantation and the use of durable LVADs as destination therapy continue to increase, these considerations will be of increasing relevance in managing advanced heart failure and improving outcomes.

Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database

BACKGROUND

Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) on the basis of relative and absolute contraindications to transplantation. Multiple factors may lead to changes in the strategy of support after LVAD implantation.

METHODS

Based on INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020 data, 11,262 patients survived to 3 months on continuous-flow LVADs with intent of BTT or DT. Preimplant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months.

RESULTS

Among 3216 BTT patients at 3 months, later transplant delisting or death without transplant occurred in 536 (16.7%) and was more common with age, profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51; P = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure as defined by inotropic therapy, predicted delisting and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33; P = 0.0024). Of 8046 patients surviving to 3 months with the intent of destination therapy, 750 (9.3%) subsequently underwent listing or transplantation, often with initial histories of acute HF (HR 1.70, 95% CI 1.27-2.27; P = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63; P = 0.0099). Multiple gastrointestinal bleeding events (≥ 4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275; P = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9; P = 0.0011).

CONCLUSIONS

Implant strategies change over time in relation to preimplant characteristics and adverse events post implant. Preimplant recognition of factors predicting later change in implant strategy will refine initial triage, whereas further reduction of post-LVAD complications will expand options, including eventual consideration of heart transplantation.

Management of patients with an electrical storm or clustered ventricular arrhythmias: a clinical consensus statement of the European Heart Rhythm Association of the ESC-endorsed by the Asia-Pacific Heart Rhythm Society, Heart Rhythm Society, and Latin-American Heart Rhythm Society

Electrical storm (ES) is a state of electrical instability, manifesting as recurrent ventricular arrhythmias (VAs) over a short period of time (three or more episodes of sustained VA within 24 h, separated by at least 5 min, requiring termination by an intervention). The clinical presentation can vary, but ES is usually a cardiac emergency. Electrical storm mainly affects patients with structural or primary electrical heart disease, often with an implantable cardioverter-defibrillator (ICD). Management of ES requires a multi-faceted approach and the involvement of multi-disciplinary teams, but despite advanced treatment and often invasive procedures, it is associated with high morbidity and mortality. With an ageing population, longer survival of heart failure patients, and an increasing number of patients with ICD, the incidence of ES is expected to increase. This European Heart Rhythm Association clinical consensus statement focuses on pathophysiology, clinical presentation, diagnostic evaluation, and acute and long-term management of patients presenting with ES or clustered VA.

Left ventricular assist devices: yesterday, today, and tomorrow

The shortcomings of expense, power requirements, infection, durability, size, and blood trauma of current durable LVADs have been recognized for many years. The LVADs of tomorrow aspire to be fully implantable, durable, mitigate infectious risk, mimic the pulsatile nature of the native cardiac cycle, as well as minimize bleeding and thrombosis. Power draw, battery cycle lifespan and trans-cutaneous energy transmission remain barriers to completely implantable systems. Potential solutions include decreases in pump electrical draw, improving battery lifecycle technology and better trans-cutaneous energy transmission, potentially from Free-range Resonant Electrical Energy Delivery. In this review, we briefly discuss the history of LVADs and summarize the LVAD devices in the development pipeline seeking to address these issues.

Tailoring left ventricular assist device cannula implantation using coupled multi-scale multi-objective optimization

BACKGROUND

The frequent occurrence of thromboembolic cerebral events continues to limit the widespread implementation of Ventricular Assist Devices (VAD) despite continued advancements in VAD design and anti-coagulation treatments. Recent studies point to the optimal positioning of the outflow graft (OG) as a potential mitigator of post implantation thromboembolism.

OBJECTIVE

This study aims to examine the tailoring of the OG implantation orientation with the goal of minimizing the number of thrombi reaching the cerebral vessels by means of a formal shape optimization scheme incorporated into a multi-scale hemodynamics analysis.

METHODS

A 3-D patient-specific computational fluid dynamics model is loosely coupled in a two-way manner to a 0-D lumped parameter model of the peripheral circulation. A Lagrangian particle-tracking scheme models and tracks thrombi as non-interacting solid spheres. The loose coupling between CFD and LPM is integrated into a geometric shape optimization scheme which aims to optimize an objective function that targets a drop in cerebral embolization, and an overall reduction in particle residence times.

RESULTS

The results elucidate the importance of OG anastomosis orientation and placement particularly in the case that studied particle release from the OG, as a fivefold decrease in cerebral embolization was observed between the optimal and non-optimal implantations. Another case considered particle release from the ventricle and aortic root walls, in which optimal implantation was achieved with a shallow insertion angle. Particle release from all three origins was investigated in the third case, demonstrating that the optimal configurations were generally characterized by VAD flow directed along the central lumen of the aortic arch. Because optimal configurations depended on the anatomic origin of the thrombus, it is important to determine, in clinical studies, the most likely sites of thrombus formation in VAD patients.

Managing ventricular arrhythmias and implantable cardiac defibrillator shocks after left ventricular assist device implantation

Continuous flow left ventricular assist devices (CF-LVADs) have been shown to reduce mortality and morbidity in patients with advanced heart failure with reduced ejection fraction. However, ventricular arrhythmias (VA) are common, are mostly secondary to underlying myocardial scar, and have a higher incidence in patients with pre-LVAD VA. Sustained VA is well tolerated in the LVAD patient but can result in implantable defibrillator (ICD) shocks, right ventricular failure, hospitalizations, and reduced quality of life. There is limited data regarding best practices for the medical management of VA as well as the role for procedural interventions in patients with uncontrolled VA and/or ICD shocks. Vast majority of CF-LVAD patients have a preexisting cardiovascular implantable electronic device (CIED) and ICD and/or cardiac resynchronization therapies are continued in many. Several questions, however, remain regarding the efficacy of ICD and CRT following CF-LVAD. Moreover, optimal CIED programming after CF-LVAD implantation. Therefore, the primary objective of this review article is to provide the most up-to-date evidence and to provide guidance on the clinical significance, pathogenesis, predictors, and management strategies for VA and ICD therapies in the CF-LVAD population. We also discuss knowledge gaps as well as areas for future research.

Durability of Tricuspid Valve Repair in Patients Undergoing Left Ventricular Assist Device Implantation

Objectives: Benefits of tricuspid valve repair (TVR) in left ventricular assist device (LVAD) patients have been questioned. High TVR failure rates have been reported. Remaining or recurring TR was found to be a risk factor for right heart failure (RHF). Therefore, we assessed our experience. Methods: Since 12/2010, 195 patients have undergone LVAD implantation in our center. Almost half (n = 94, 48%) received concomitant TVR (LVAD+TVR). These patients were included in our analysis. Echocardiographic and clinical data were assessed. Median follow-up was 2.8 years (7 days-0.6 years). Results were correlated with clinical outcomes. Results: LVAD+TVR patients were 59.8 ± 11.4 years old (89.4% male) and 37.3% were INTERMACS level 1 and 2. Preoperative TR was moderate in 28 and severe in 66 patients. RV function was severely impaired in 61 patients reflected by TAPSE-values of 11.2 ± 2.9 mm (vs. 15.7 ± 3.8 mm in n = 33; p < 0.001). Risk for RHF according to EUROMACS-RHF risk score was high (>4 points) in 60 patients, intermediate (>2-4 points) in 19 and low (0-2 points) in 15. RHF occurred in four patients (4.3%). Mean duration of echocardiographic follow-up was 2.8 ± 2.3 years. None of the patients presented with severe and only five (5.3%) with moderate TR. The vast majority (n = 63) had mild TR, and 26 patients had no/trace TR. Survival at 1, 3 and 5 years was 77.4%, 68.1% and 55.6%, 30-day mortality was 11.7% (n = 11). Heart transplantation was performed in 12 patients (12.8%). Conclusions: Contrary to expectations, concomitant TVR during LVAD implantation may result in excellent repair durability, which appears to be associated with low risk for RHF.

Hemocompatibility and biophysical interface of left ventricular assist devices and total artificial hearts

ABSTRACT

Over the past 2 decades, there has been a significant increase in the utilization of long-term mechanical circulatory support (MCS) for the treatment of cardiac failure. Left ventricular assist devices (LVADs) and total artificial hearts (TAHs) have been developed in parallel to serve as bridge-to-transplant and destination therapy solutions. Despite the distinct hemodynamic characteristics introduced by LVADs and TAHs, a comparative evaluation of these devices regarding potential complications in supported patients, has not been undertaken. Such a study could provide valuable insights into the complications associated with these devices. Although MCS has shown substantial clinical benefits, significant complications related to hemocompatibility persist, including thrombosis, recurrent bleeding, and cerebrovascular accidents. This review focuses on the current understanding of hemostasis, specifically thrombotic and bleeding complications, and explores the influence of different shear stress regimens in long-term MCS. Furthermore, the role of endothelial cells in protecting against hemocompatibility-related complications of MCS is discussed. We also compared the diverse mechanisms contributing to the occurrence of hemocompatibility-related complications in currently used LVADs and TAHs. By applying the existing knowledge, we present, for the first time, a comprehensive comparison between long-term MCS options.

Advanced Heart Failure: Therapeutic Options and Challenges in the Evolving Field of Left Ventricular Assist Devices

Heart Failure is a chronic and progressively deteriorating syndrome that has reached epidemic proportions worldwide. Improved outcomes have been achieved with novel drugs and devices. However, the number of patients refractory to conventional medical therapy is growing. These advanced heart failure patients suffer from severe symptoms and frequent hospitalizations and have a dismal prognosis, with a significant socioeconomic burden in health care systems. Patients in this group may be eligible for advanced heart failure therapies, including heart transplantation and chronic mechanical circulatory support with left ventricular assist devices (LVADs). Heart transplantation remains the treatment of choice for eligible candidates, but the number of transplants worldwide has reached a plateau and is limited by the shortage of donor organs and prolonged wait times. Therefore, LVADs have emerged as an effective and durable form of therapy, and they are currently being used as a bridge to heart transplant, destination lifetime therapy, and cardiac recovery in selected patients. Although this field is evolving rapidly, LVADs are not free of complications, making appropriate patient selection and management by experienced centers imperative for successful therapy. Here, we review current LVAD technology, indications for durable MCS therapy, and strategies for timely referral to advanced heart failure centers before irreversible end-organ abnormalities.

Pectoral muscle mass is not a robust prognostic factor for survival after left ventricular assist device (LVAD) implantation

BACKGROUND

Left ventricular assist devices (LVAD) are an established treatment for end-stage left ventricular heart failure. Parameters are needed to identify the most appropriate patients for LVADs. This study aimed to evaluate pectoral muscle mass and density as prognostic parameters.

METHODS

This single-center study included all patients with LVAD implantation between January 2010 and October 2017 and a preoperative chest CT scan. Pectoral muscle mass was assessed using the Pectoralis Muscle Index (PMI, surface area indexed to height, cm2/m2) and pectoral muscle density by Hounsfield Units (HU). Overall mortality was analyzed with Kaplan-Meier survival analysis and 1-year and 3-year mortality with receiver operating characteristic (ROC) curves and Cox regression models.

RESULTS

57 patients (89.5% male, mean age 57.8 years) were included. 64.9% of patients had end-stage left ventricular failure due to ischemic heart disease and 35.1% due to dilated cardiomyopathy. 49.2% of patients had preoperative INTERMACS profile of 1 or 2 and 33.3% received mechanical circulatory support prior to LVAD implantation. Total mean PMI was 4.7 cm2/m2 (± 1.6), overall HU of the major pectoral muscle was 39.0 (± 14.9) and of the minor pectoral muscle 37.1 (± 16.6). Mean follow-up was 2.8 years (± 0.2). Mortality rates were 37.5% at 1 year and 48.0% at 3 years. Neither PMI nor HU were significantly associated with overall mortality at 1-year or 3-year.

CONCLUSIONS

The results of our study do not confirm the association between higher pectoral muscle mass and better survival after LVAD implantation previously described in the literature.

Ventricular Arrhythmias in Left Ventricular Assist Device Patients-Current Diagnostic and Therapeutic Considerations

Left ventricular assist devices (LVAD) are used in the treatment of advanced left ventricular heart failure. LVAD can serve as a bridge to orthotopic heart transplantation or as a destination therapy in cases where orthotopic heart transplantation is contraindicated. Ventricular arrhythmias are frequently observed in patients with LVAD. This problem is further compounded as a result of diagnostic difficulties arising from presently available electrocardiographic methods. Due to artifacts from LVAD-generated electromagnetic fields, it can be challenging to assess the origin of arrhythmias in standard ECG tracings. In this article, we will review and discuss common mechanisms, diagnostics methods, and therapeutic strategies for ventricular arrhythmia treatment, as well as numerous problems we face in LVAD implant patients.

Integration of implantable device therapy in patients with heart failure. A clinical consensus statement from the Heart Failure Association (HFA) and European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC)

Implantable devices form an integral part of the management of patients with heart failure (HF) and provide adjunctive therapies in addition to cornerstone drug treatment. Although the number of these devices is growing, only few are supported by robust evidence. Current devices aim to improve haemodynamics, improve reverse remodelling, or provide electrical therapy. A number of these devices have guideline recommendations and some have been shown to improve outcomes such as cardiac resynchronization therapy, implantable cardioverter-defibrillators and long-term mechanical support. For others, more evidence is still needed before large-scale implementation can be strongly advised. Of note, devices and drugs can work synergistically in HF as improved disease control with devices can allow for further optimization of drug therapy. Therefore, some devices might already be considered early in the disease trajectory of HF patients, while others might only be reserved for advanced HF. As such, device therapy should be integrated into HF care programmes. Unfortunately, implementation of devices, including those with the greatest evidence, in clinical care pathways is still suboptimal. This clinical consensus document of the Heart Failure Association (HFA) and European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) describes the physiological rationale behind device-provided therapy and also device-guided management, offers an overview of current implantable device options recommended by the guidelines and proposes a new integrated model of device therapy as a part of HF care.

Pre- and Post-Implant Endoscopy in Left Ventricular Assist Device Recipients: A Single-Center Experience

Background

Gastrointestinal bleeding (GIB) is common in left ventricular assist devices (LVADs) patients, but the optimal screening approach before LVAD implantation is still unclear. The aim of the study was to describe our experience with pre- and post-LVAD implantation endoscopic screening and subsequent GI bleeding in this cohort.

Methods

A retrospective review was conducted among all patients who underwent LVAD implantation at Saint Luke's Hospital, between 2010 and 2020. The data were reviewed to determine the yield and safety of endoscopic procedures performed within 1 month before LVAD placement and the incidence of GIB within 1 year after implantation.

Results

A total of 167 LVAD patients met the inclusion criteria, and 23 underwent pre-implantation endoscopic evaluation. Angiodysplasia had a significantly higher odds ratio (OR) of 9.41 (95% confidence interval (CI): 2.01 - 44.09) in post-LVAD endoscopy, while there was no significant difference in bleeding from other sources such as peptic ulcer disease or diverticular bleeding. There was no difference in the incidence of GIB in patients who underwent endoscopic evaluation pre-LVAD compared to post-LVAD GIB (32.6% vs. 39.1%, P = 0.64). Endoscopy was well-tolerated in this cohort, and argon plasma coagulation was the most commonly used intervention to achieve hemostasis.

Conclusions

According to our results, we recommend against routine pre-LVAD endoscopic screening. Instead, we suggest an individualized approach, where decisions are made on a case-by-case basis.

Partial Pressure of End-Tidal Oxygen and Blood Lactate During Cardiopulmonary Exercise Testing in Healthy Older Participants and Patients at Risk of Cardiac Disease

Background

The partial pressure of end-tidal oxygen (PETO2) and end-tidal oxygen concentration (ETO2) are among the indices that can be measured by exhaled gas analysis. Several observational studies have shown that skeletal muscle function is impaired in patients with cardiac disease; thus, the assessment of skeletal muscle function is important. Additionally, although it has recently been suggested that the difference in PETO2 from rest to the ventilatory anaerobic threshold (VAT) reflects oxygen availability in peripheral factors, primarily skeletal muscle, the evidence for this is not well established. Therefore, we hypothesized and investigated whether increased blood lactate (BLa) levels, resulting from decreased skeletal muscle and mitochondrial oxygen availability, and PETO2 dynamics during cardiopulmonary exercise testing (CPET) would be related.

Methods

All participants performed the symptomatic limited CPET, and their BLa levels were measured. The difference in PETO2 and ETO2 from rest to VAT determined by the V-slope method (ΔPETO2 and ΔETO2) was calculated and compared with the increase in BLa due to exercise testing.

Results

We recruited 22 healthy older participants (nine males; 69.4 ± 6.8 years) and 11 patients with cardiovascular risk (eight males; 73.0 ± 8.8 years). ΔPETO2 and ΔETO2 did not differ between the two groups (P = 0.355 and P = 0.369, respectively), showing no correlation between increase in BLa from rest to VAT, but were significantly correlated with an increase in BLa from rest to the end of exercise (ΔPETO2, P = 0.030; ΔETO2, P = 0.029). The correlation was particularly pronounced among those at cardiovascular risk (ΔPETO2, P = 0.012; ΔETO2, P = 0.011).

Conclusions

ΔPETO2 and ΔETO2 from rest to VAT during CPET may be useful as indices reflecting skeletal muscle oxygen utilization capacity.

A low-dose thrombolytic infusion protocol for safe and successful treatment of left ventricular assist device thrombosis: a case series

Background

Pump thrombosis is a serious complication of continuous-flow left ventricular assist device (CF-LVAD) therapy. In this study, we aim to report a novel protocol of an intermittent, low-dose, and slow infusion of tissue plasminogen activator (alteplase).

Case summary

We treated seven LVAD pump thrombosis events (HeartMate® II and HeartWare) in four patients with a median age of 52 years (31-63), and all were female. The protocol was applied from January 2015 to December 2018, and it consisted of an intermittent, low-dose, and slow infusion of systemic thrombolytic therapy in the intensive care unit. This therapy resulted in successful resolution of pump thrombosis in six out of seven events. Bleeding complication occurred in one patient, which included a ruptured haemorrhagic ovarian cyst and a small cerebellar intra-parenchymal haemorrhage. All patients were discharged home in a stable condition, except one patient who died during hospitalization because of severe sepsis, pump thrombosis with subsequent pump exchange, and multi-organ failure.

Discussion

A low-dose, prolonged, and systemic thrombolytic infusion protocol is an effective and relatively safe treatment that can lead to a sustained resolution of pump thrombosis with low bleeding complications and failure rates.

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices

Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failure refractory to medical therapy. However, the incidence of ventricular arrhythmias (VAs) is high in this population, both in the acute and delayed phases after implantation. About one-third of patients implanted with an LVAD will experience sustained VAs, predisposing these patients to worse outcomes and complicating patient management. The combination of pre-existing myocardial substrate and complex electrical remodeling after LVAD implantation account for the high incidence of VAs observed in this population. LVAD patients presenting VAs refractory to antiarrhythmic therapy and catheter ablation procedures are not rare. In such patients, treatment options are extremely limited. Stereotactic body radiation therapy (SBRT) is a technique that delivers precise and high doses of radiation to highly defined targets, reducing exposure to adjacent normal tissue. Cardiac SBRT has recently emerged as a promising alternative with a growing number of case series reporting the effectiveness of the technique in reducing the VA burden in patients with arrhythmias refractory to conventional therapies. The safety profile of cardiac SBRT also appears favorable, even though the current clinical experience remains limited. The use of cardiac SBRT for the treatment of refractory VAs in patients implanted with an LVAD are even more scarce. This review summarizes the clinical experience of cardiac SBRT in LVAD patients and describes technical considerations related to the implementation of the SBRT procedure in the presence of an LVAD.

Evolution of Mechanical Circulatory Support for advanced heart failure

This comprehensive review highlights the significant advancements in Left Ventricular Assist Device (LVAD) therapy, emphasizing its evolution from the early pulsatile flow systems to the cutting-edge continuous-flow devices, particularly the HeartMate 3 (HM3) LVAD. These advancements have notably improved survival rates, reduced complications, and enhanced the quality of life (QoL) for patients with advanced heart failure. The dual role of LVADs, as a bridge-to-transplantation and destination therapy is discussed, highlighting the changing trends and policies in their application. The marked reduction in hemocompatibility-related adverse events (HRAE) with the HM3 LVAD, compared to previous models signifies ongoing progress in the field. Challenges such as managing major infections are discussed, including innovative solutions like energy transfer systems aimed at eliminating external drivelines. It explores various LVAD-associated complications, including HRAE, infections, hemodynamic-related adverse events, and cardiac arrhythmias, and underscores emerging strategies for predicting post-implantation outcomes, fostering a more individualized patient care approach. Tools such as the HM3 risk score are introduced for predicting survival based on pre-implant factors, along with advanced imaging techniques for improved complication prediction. Additionally, the review highlights potential new technologies and therapies in LVAD management, such as hemodynamic ramp tests for optimal speed adjustment and advanced remote monitoring systems. The goal is to automate LVAD speed adjustments based on real-time hemodynamic measurements, indicating a shift towards more effective, patient-centered therapy. The review concludes optimistically that ongoing research and potential future innovations hold the promise of revolutionizing heart failure management, paving the way for more effective and personalized treatment modalities.

Clinical and economic impact of ventricular assist device infections: a real-world claims analysis

BACKGROUND

VAD therapy has revolutionized the treatment of end-stage heart failure, but infections remain an important complication. The objective of this study was to characterize the clinical and economic impacts of VAD-specific infections.

METHODS

A retrospective analysis of a United States claims database identified members ≥ 18 years with a claim for a VAD implant procedure, at least 6 months of pre-implant baseline data, and 12 months of follow-up between 1 June 2016 and 31 December 2019. Cumulative incidence of infection was calculated. Infection and non-infection cohorts were compared regarding mortality, healthcare utilization, and total cost. Regression models were used to identify risk factors associated with infections and mortality.

RESULTS

A total of 2,259 patients with a VAD implant were included, with 369 experiencing infection (12-month cumulative incidence 16.1%). Patients with infection were 2.1 times more likely to die (p < 0.001, 95% CI [1.5-2.9]). The mean 12-month total cost per US patient was $354,339 for the non-infection cohort and $397,546 for the infection cohort, a difference of $43,207 (p < 0.0001).

CONCLUSIONS

VAD infections were associated with higher mortality, more healthcare utilization, and higher total cost. Strategies to minimize VAD-specific infections could lead to improved clinical and economic outcomes.

Cellular and Molecular Mechanisms Activated by a Left Ventricular Assist Device

Left ventricular assist devices (LVADs) represent the final treatment for patients with end-stage heart failure (HF) not eligible for transplantation. Although LVAD design has been further improved in the last decade, their use is associated with different complications. Specifically, inflammation, fibrosis, bleeding events, right ventricular failure, and aortic valve regurgitation may occur. In addition, reverse remodeling is associated with substantial cellular and molecular changes of the failing myocardium during LVAD support with positive effects on patients' health. All these processes also lead to the identification of biomarkers identifying LVAD patients as having an augmented risk of developing associated adverse events, thus highlighting the possibility of identifying new therapeutic targets. Additionally, it has been reported that LVAD complications could cause or exacerbate a state of malnutrition, suggesting that, with an adjustment in nutrition, the general health of these patients could be improved.

Post-transplant survival with pre-transplant durable continuous-flow mechanical circulatory support in a Swiss cohort of heart transplant recipients

BACKGROUND

Worldwide, almost half of all heart transplantation candidates arrive today at their transplant operation with durable continuous-flow mechanical circulatory support (CF-MCS). This evolution is due to a progressive increase of waiting list time and hence an increased risk of haemodynamic worsening. Longer duration of CF-MCS is associated with a higher risk of device-related complications with potential adverse impact on post-transplant outcome as suggested by recent results from the United Network of Organ Sharing of the United States.

METHODS

A 2-centre Swiss heart transplantation programme conducted a retrospective observational study of consecutive patients of theirs who underwent a transplant in the period 2008-2020. The primary aim was to determine whether post-transplant all-cause mortality is different between heart transplant recipients without or with pre-transplant CF-MCS. The secondary outcome was the acute cellular rejection score within the first year post-transplant.

RESULTS

The study participants had a median age of 54 years; 38/158 (24%) were females. 53/158 study participants (34%) had pre-transplant CF-MCS with a median treatment duration of 280 days. In heart transplant recipients with pre-transplant CF-MCS, the prevalence of ischaemic cardiomyopathy was higher (51 vs 32%; p = 0.013), the left ventricular ejection fraction was lower (20 vs 25; p = 0.047) and pulmonary vascular resistance was higher (2.3 vs 2.1 Wood Units; p = 0.047). Over the study period, the proportion of heart transplant recipients with pre-transplant CF-MCS and the duration of pre-transplant CF-MCS treatment increased (2008-2014 vs 2015-2020: 22% vs 45%, p = 0.009; increase of treatment days per year: 34.4 ± 11.2 days, p = 0.003; respectively). The primary and secondary outcomes were not different between heart transplant recipients with pre-transplant CF-MCS or direct heart transplantation (log-rank p = 0.515; 0.16 vs 0.14, respectively; p = 0.81).

CONCLUSION

This data indicates that the strategy of pre-transplant CF-MCS with subsequent orthotopic heart transplantation provides post-transplant outcomes not different to direct heart transplantation despite the fact that the duration of pre-transplant assist device treatment has progressively increased.

Impact of time off anticoagulation in patients with continuous-flow left ventricular assist devices

Patients with left ventricular assist devices (LVADs) receive anticoagulation to decrease the risk of thrombosis. Various circumstances require discontinuing anticoagulation in LVAD patients, but the risks entailed are not well defined. In a retrospective review of LVAD implantation procedures, we examined the effect of time off anticoagulation on thrombosis and mortality rates after implantation. An international normalized ratio ≤ 1.5 was used to screen for patients taken off anticoagulation. Patients were divided into three groups by the cumulative number of days off anticoagulation: no discontinuation, short-term discontinuation (< 30 days), and long-term discontinuation (≥ 30 days). Rates of ischemic stroke, pump thrombosis, and mortality were compared among groups. Of 245 patients who underwent LVAD implantation during the study, 70 (28.6%) were off anticoagulation during follow-up: 37 (15.1%) had short-term discontinuation (median, 11 days), and 33 (13.5%) had long-term discontinuation (median, 124 days). Patients with long-term discontinuation had a higher rate of ischemic stroke (adjusted hazard ratio 8.5, p = 0.001) and death (adjusted hazard ratio 3.9, p = 0.001). The three groups did not differ in pump thrombosis rate. We conclude that after LVAD implantation, discontinuing anticoagulation for ≥ 30 days is independently associated with an increased risk of ischemic stroke and death.

When all Else Fails, Try This: The HeartMate III Left Ventricle Assist Device

Heart failure (HF) is a progressive disease. It is estimated that more than 250,000 patients suffer from advanced HF with reduced ejection fraction refractory to medical therapy. With limited donor pool for heart transplant, continue flow left ventricle assist device (LVAD) is a lifesaving treatment option for patients with advanced HF. This review will provide an update on indications, contraindications, and associated adverse events for LVAD support with a summary of the current outcomes data.

Trends and predictors of intracranial hemorrhage in patients with advanced heart failure on left ventricular assist device from 2005 to 2014 in the United States

OBJECTIVES

Left ventricular assist devices are known to extend survival in patients with advanced heart failure; however, their association with intracranial hemorrhage is also well-known. We aimed to explore the risk trend and predictors of intracranial hemorrhage in patients with left ventricular assist devices.

MATERIAL AND METHODS

We included patients aged 18 years or older with left ventricular assist devices hospitalized in the US from 2005 to 2014 using the National Inpatient Sample. We computed the survey-weighted percentages with intracranial hemorrhage across the 10-year study period and assessed whether the proportions changed over time. Predictors of intracranial hemorrhage were evaluated using multivariable logistic regression model.

RESULTS

Of 33,246 hospitalizations, 568 (1.7%) had intracranial hemorrhage. The number of left ventricular assist devices placements increased from 873 in 2005 to 5175 in 2014. However, the risk of intracranial hemorrhage remained largely unchanged (1.7% to 2.3%; linear trend, P = 0.604). The adjusted odds of intracranial hemorrhage were increased with the presence of one of the following variables: female sex (odds ratio [OR], 1.58; 95% CI, 1.03-2.43), history of ischemic stroke (OR, 3.13; 95% CI, 1.86-5.28), or Charlson Comorbidity Index score of 3 or more (OR, 77.40; 95% CI, 10.03-597.60).

CONCLUSIONS

Over the last decade, the risk of intracranial hemorrhage has remained relatively unchanged despite an increase in the use of left ventricular assist devices in patients with advanced heart failure. Women, higher Charlson Comorbidity Index scores, and history of ischemic stroke were associated with higher odds of intracranial hemorrhage in patients with left ventricular assist devices.

Effect of Aortic Valve Opening Pattern on Endothelial Function After Continuous-Flow Left Ventricular Assist Device Implantation

This study aimed to evaluate the effects of aortic valve opening patterns on endothelial functions in patients undergoing continuous-flow left ventricular assist device (CF-LVAD) implantation. This study included 43 patients who underwent CF-LVAD implantation and 35 patients with heart failure reduced ejection fraction (HFrEF; control group). The CF-LVAD group was divided into three subgroups based on aortic valve opening patterns: open with each beat, intermittently opening, and not opening groups. Flow-mediated dilatation (FMD) and pulsatility index (PI) were compared before and 3 months after CF-LVAD implantation. Cardiopulmonary exercise test (CPET) and 6 minute walk test (6-MWT) scores were measured at baseline and follow-up in the CF-LVAD group. The mean FMD and PI of patients in the CF-LVAD group reduced 3 months after implantation. Patients with intermittently opening and not opening aortic valves had worse endothelial function at follow-up. Before and 3 months after implantation FMD% did not significantly differ in patients whose aortic valves were open with each beat (4.72 ± 1.06% vs. 4.67 ± 1.16%, p = 0.135). Pulsatility index changes paralleled FMD changes. Cardiopulmonary exercise test and 6-MWT scores improved after implantation but without significant differences between subgroups. Maintaining normal aortic valve function after CF-LVAD implantation may reduce endothelial dysfunction; however, larger studies are needed for long-term clinical effects.

Review of Implantable Left Ventricular Assist Devices

Mechanical circulatory support has been an indispensable treatment for severe heart failure. While the development of a total artificial heart has failed, left ventricular assist devices (LVAD) have evolved from extracorporeal to implantable types. The first generation implantable LVAD (pulsatile device) was used as a bridge to transplantation, and demonstrated improvement in survival rate and activity of daily living. The evolution from the first-generation (pulsatile device) to the second-generation (continuous flow device: axial flow pump and centrifugal pump) has resulted in many clinical benefits by reducing mechanical failures and minimizing device size. Furthermore, third-generation devices, which use a moving impeller suspended by magnetic and/or hydrodynamic forces, have improved overall device reliability and durability. Unfortunately, there are still many device-related complications, and further device development and improvement of patient management methods are required. However, we expect to see further development of implantable VADs, including for destination therapy, in future.

Design and characteristics of the prophylactic intra-operative ventricular arrhythmia ablation in high-risk LVAD candidates (PIVATAL) trial

BACKGROUND

The use of a Left Ventricular Assist Device (LVAD) in patients with advanced heart failure refractory to optimal medical management has progressed steadily over the past two decades. Data have demonstrated reduced LVAD efficacy, worse clinical outcome, and higher mortality for patients who experience significant ventricular tachyarrhythmia (VTA). We hypothesize that a novel prophylactic intra-operative VTA ablation protocol at the time of LVAD implantation may reduce the recurrent VTA and adverse events postimplant.

METHODS

We designed a prospective, multicenter, open-label, randomized-controlled clinical trial enrolling 100 patients who are LVAD candidates with a history of VTA in the previous 5 years. Enrolled patients will be randomized in a 1:1 fashion to intra-operative VTA ablation (n = 50) versus conventional medical management (n = 50) with LVAD implant. Arrhythmia outcomes data will be captured by an implantable cardioverter defibrillator (ICD) to monitor VTA events, with a uniform ICD programming protocol. Patients will be followed prospectively over a mean of 18 months (with a minimum of 9 months) after LVAD implantation to evaluate recurrent VTA, adverse events, and procedural outcomes. Secondary endpoints include right heart function/hemodynamics, healthcare utilization, and quality of life.

CONCLUSION

The primary aim of this first-ever randomized trial is to assess the efficacy of intra-operative ablation during LVAD surgery in reducing VTA recurrence and improving clinical outcomes for patients with a history of VTA.

Left ventricular assist device thrombosis in the setting of supratherapeutic international normalized ratio (INR) and bleeding

A 71-year-old female with heart failure who underwent left ventricular assist device (LVAD) placement presented for evaluation of low hemoglobin and dark stools. She also had leg pain, numbness, and weakness for which she was taking ibuprofen. She was found to have a gastrointestinal bleed, INR of 4.3, and arterial thrombi in the left leg. She was stabilized, had her anticoagulation held, and underwent mechanical thrombectomy. On hospital day 6, LVAD interrogation revealed signs of thrombosis, while subsequent labs revealed a persistently supratherapeutic INR of 5.2. The patient had the LVAD removed and underwent further hematologic workup. Her platelets remained normal throughout the admission, indicating this was not acute disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), or heparin induced thrombocytopenia (HIT). Echocardiography identified it as a primary thrombus. This case illustrates the importance of appropriate anticoagulation to balance the bleeding risk with the risk of thrombi, as well as the importance of maintaining high suspicion for LVAD thrombosis regardless of INR.

Less Invasive Left Ventricular Assist Device Implantation Is Safe and Feasible in Patients With Smaller Body Surface Area

OBJECTIVE

Smaller body surface area (BSA) frequently precludes patients from left ventricular assist device (LVAD) therapy. We sought to investigate the clinical outcomes in patients with small BSA undergoing less invasive LVAD implantation.

METHODS

We conducted a retrospective review of 216 patients implanted with HeartMate 3 LVAD (Abbott, Chicago, IL) via less invasive surgery at our institution. Patients were dichotomized based on their preimplant BSA for comparison between small BSA (≤1.8 m2) and normal/large BSA (>1.8 m2). We analyzed patient perioperative characteristics and outcomes.

RESULTS

In our study, small BSA was found in 32 patients (14.8%), while 184 patients (85.2%) had normal/large BSA. Women were more prevalent in the small BSA group (50.0% vs 13.0%, P < 0.001). Preoperative and intraoperative data showed comparable results. Major complications and hospital length of stay did not differ by BSA group. Patients with smaller BSA had significantly decreased pump parameters at discharge, including LVAD flow (4.11 ± 0.49 vs 4.60 ± 0.54 L/min, P < 0.001) and pump speed (5,200 vs 5,400 rpm, P < 0.001). Survival to discharge and within 6 months after implantation were similar between the groups.

CONCLUSIONS

Our study results suggest that less invasive HeartMate 3 implantation can be safely performed and demonstrates equivalent outcomes in patients with smaller body habitus. Randomized trials are required to confirm our data.

Pulmonary Capillary Recruitment Is Attenuated Post Left Ventricular Assist Device Implantation

There is limited knowledge of pulmonary physiology and pulmonary function after continuous flow-left ventricular assist device (CF-LVAD) implantation. Therefore, this study investigated whether CF-LVAD influenced pulmonary circulation by assessing pulmonary capillary blood volume and alveolar-capillary conductance in addition to pulmonary function in patients with heart failure. Seventeen patients with severe heart failure who were scheduled for CF-LVAD implantation (HeartMate II, III, Abbott, Abbott Park, IL or Heart Ware, Medtronic, Minneapolis, MN) participated in the study. They underwent pulmonary function testing (measures of lung volumes and flow rates) and unique measures of pulmonary physiology using a rebreathe technique that quantified the diffusing capacity of the lungs for carbon monoxide (DLCO) and diffusing capacity of the lungs for nitric oxide before and 3 months after CF-LVAD implantation. After CF-LVAD, pulmonary function was not significantly changed (p >0.05). For lung diffusing capacity, alveolar volume (VA) was not changed (p = 0.47), but DLCO was significantly reduced (p = 0.04). After correcting for VA, DLCO/VA showed a trend toward reduction (p = 0.08). For the alveolar-capillary component, capillary blood volume (Vc) was significantly reduced (p = 0.04), and alveolar-capillary membrane conductance trended toward a reduction (p = 0.06). However, alveolar-capillary membrane conductance/Vc was not altered (p = 0.92). In conclusion, soon after CF-LVAD implantation, Vc is reduced likely because of pulmonary capillary derecruitment, which contributes to the decrease in lung diffusing capacity.

The First Dedicated Comprehensive Heart Failure Program in the United States: The Division of Circulatory Physiology at Columbia Presbyterian (1992-2004)

The first dedicated multidisciplinary heart failure program in the United States was founded as the Division of Circulatory Physiology at the Columbia University College of Physicians & Surgeons in 1992. The Division was administratively and financially independent of the Division of Cardiology and grew to 24 faculty members at its peak. Its administrative innovations included (1) a comprehensive full-integrated service line, with 2 differentiated clinical teams, one devoted to drug therapy and the other to heart transplantation and ventricular assist devices; (2) a nurse specialist/physician assistant-led clinical service; and (3) a financial structure independent of (and not supported by) other cardiovascular medical or surgical services. The division had 3 overarching missions: (1) to promote a unique career development path for each faculty member to be linked to recognition in a specific area of heart failure expertise; (2) to change the trajectory and enhance the richness of intellectual discourse in the discipline of heart failure, so as to foster an understanding of fundamental mechanisms and to develop new therapeutics; and (3) to provide optimal medical care to patients and to promote the ability of other physicians to provide optimal care. The major research achievements of the division included (1) the development of beta-blockers for heart failure, from initial hemodynamic assessments to proof-of-concept studies to large-scale international trials; (2) the development and definitive assessment of flosequinan, amlodipine, and endothelin antagonists; (3) initial clinical trials and concerns with nesiritide; (4) large-scale trials evaluating dosing of angiotensin converting-enzyme inhibitors and the efficacy and safety of neprilysin inhibition; (5) identification of key mechanisms in heart failure, including neurohormonal activation, microcirculatory endothelial dysfunction, deficiencies in peripheral vasodilator pathways, noncardiac factors in driving dyspnea, and the first identification of subphenotypes of heart failure and a preserved ejection fraction; (6) the development of a volumetric approach to the assessment of myocardial shortening; (7) conceptualization and early studies of cardiac contractility modulation as a treatment for heart failure; (8) novel approaches to the identification of cardiac allograft rejection and new therapeutics to prevent allograft vasculopathy; and (9) demonstration of the effect of left ventricular assist devices to induce reverse remodeling, and the first randomized trial showing a survival benefit with ventricular assist devices. Above all, the division served as an exceptional incubator for a generation of leaders in the field of heart failure.

Blood flow kinetic energy is a novel marker for right ventricular global systolic function in patients with left ventricular assist device therapy

Objectives

Right ventricular (RV) failure remains a major concern in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implantation. We aimed to measure the kinetic energy of blood in the RV outflow tract (KE-RVOT) - a new marker of RV global systolic function. We also aimed to assess the relationship of KE-RVOT to other echocardiographic parameters in all subjects and assess the relationship of KE-RVOT to hemodynamic parameters of RV performance in HF patients.

Methods

Fifty-one subjects were prospectively enrolled into 4 groups (healthy controls, NYHA Class II, NYHA Class IV, LVAD patients) as follows: 11 healthy controls, 32 HF patients (8 NYHA Class II and 24 Class IV), and 8 patients with preexisting LVADs. The 24 Class IV HF patients included 21 pre-LVAD and 3 pre-transplant patients. Echocardiographic parameters of RV function (TAPSE, St', Et', IVA, MPI) and RV outflow color-Doppler images were recorded in all patients. Invasive hemodynamic parameters of RV function were collected in all Class IV HF patients. KE-RVOT was derived from color-Doppler imaging using a vector flow mapping proprietary software. Kruskal-Wallis test was performed for comparison of KE-RVOT in each group. Correlation between KE-RVOT and echocardiographic/hemodynamic parameters was assessed by linear regression analysis. Receiver operating characteristic curves for the ability of KE-RVOT to predict early phase RV failure were generated.

Results

KE-RVOT (median ± IQR) was higher in healthy controls (55.10 [39.70 to 76.43] mW/m) than in the Class II HF group (22.23 [15.41 to 35.58] mW/m, p < 0.005). KE-RVOT was further reduced in the Class IV HF group (9.02 [5.33 to 11.94] mW/m, p < 0.05). KE-RVOT was lower in the LVAD group (25.03 [9.88 to 38.98] mW/m) than the healthy controls group (p < 0.005). KE-RVOT had significant correlation with all echocardiographic parameters and no correlation with invasive hemodynamic parameters. RV failure occurred in 12 patients who underwent LVAD implantation in the Class IV HF group (1 patient was not eligible due to death immediately after the LVAD implantation). KE-RVOT cut-off value for prediction of RV failure was 9.15 mW/m (sensitivity: 0.67, specificity: 0.75, AUC: 0.66).

Conclusions

KE-RVOT, a novel noninvasive measure of RV function, strongly correlates with well-established echocardiographic markers of RV performance. KE-RVOT is the energy generated by RV wall contraction. Therefore, KE-RVOT may reflect global RV function. The utility of KE-RVOT in prediction of RV failure post LVAD implantation requires further study.

Gastrointestinal bleeding in recipients of left ventricular assist devices-a systematic review

The twenty-first century has revolutionized the management of congestive heart failure with the widespread use of left ventricular assist devices and other treatment modalities that improve morbidity and mortality after the failure of medical management. These novel devices come with significant side effects. One of the most common side effects of left ventricular assist devices is the increased frequency of lower gastrointestinal bleeding compared to heart failure patients without left ventricular assist devices. Multiple etiologies of recurrent gastrointestinal bleeding in such patients have been studied. The decreased amount of von Willebrand factor polymers is now recognized as one of the most common causes of increased incidence of gastrointestinal bleeding in patients with left ventricular assist devices alongside increased arteriovenous malformations. Multiple treatment modalities have been identified to prevent and treat gastrointestinal bleeding in these patients. Since the use of left ventricular assist devices is becoming more prevalent in patients with advanced heart failure, we decided to conduct this systematic review. The article summarizes the incidence, pathophysiology, and management of lower gastrointestinal bleeding in patients with left ventricular assist devices.

Efficacy of levosimendan infusion in patients undergoing a left ventricular assist device implant in a propensity score matched analysis of the EUROMACS registry-the Euro LEVO-LVAD study

OBJECTIVES

Early right-sided heart failure (RHF) was seen in 22% of recipients of a left ventricular assist device (LVAD) in the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). However, the optimal treatment of post-LVAD RHF is not well known. Levosimendan has proven to be effective in patients with cardiogenic shock and in those with end-stage heart failure. We sought to evaluate the efficacy of levosimendan on post-LVAD RHF and 30-day and 1-year mortality.

METHODS

The EUROMACS Registry was used to identify adults with mainstream continuous-flow LVAD implants who were treated with preoperative levosimendan compared to a propensity matched control cohort.

RESULTS

In total, 3661 patients received mainstream LVAD, of which 399 (11%) were treated with levosimendan pre-LVAD. Patients given levosimendan had a higher EUROMACS RHF score [4 (2- 5.5) vs 2 (2- 4); P < 0.001], received more right ventricular assist devices (RVAD) [32 (8%) vs 178 (5.5%); P = 0.038] and stayed longer in the intensive care unit post-LVAD implant [19 (8-35) vs 11(5-25); P < 0.001]. Yet, there was no significant difference in the rate of RHF, 30-day, or 1-year mortality. Also, in the matched cohort (357 patients taking levosimendan compared to an average of 622 controls across 20 imputations), we found no evidence for a difference in postoperative severe RHF, RVAD implant rate, length of stay in the intensive care unit or 30-day and 1-year mortality.

CONCLUSIONS

In this analysis of the EUROMACS registry, we found no evidence for an association between levosimendan and early RHF or death, albeit patients taking levosimendan had much higher risk profiles. For a definitive conclusion, a multicentre, randomized study is warranted.

Endovascular stenting of an HVAD™ outflow graft pseudoaneurysm that exerts compression and kinking stenosis on the soft portion of the prosthesis

Key Clinical Message

Complex presentations of MCS patients may necessitate a multidisciplinary approach involving HF cardiologists, CT surgeons, advanced cardiac imagers, and interventional cardiologists in order to define the optimal management strategy.

Abstract

Left ventricle assist devices (LVADs) provide life-sustaining treatment for patients with terminal heart failure, but their intricacy allows for complications. One complication is LVAD outflow graft obstruction due to the graft's intraluminal thrombus or extraluminal compression. It may be treated endovascularly with stenting. We report an endovascular stenting of an outflow tract in HVAD™ (HeartWare Inc.) due to a pseudoaneurysm causing compression and kinking stenosis.

Continuous-Flow Ventricular Assist Device Support in Adult Congenital Heart Disease: A 15-Year, Multicenter Experience of Temporary and Durable Support

Heart failure (HF) is common in adult congenital heart disease (ACHD) patients; however, use of continuous-flow ventricular assist devices (CF-VADs) remains rare. We reviewed outcomes of patients with congenital heart disease greater than or equal to 18 years of age at the time of CF-VAD implant at the affiliated pediatric and adult institutions between 2006 and 2020. In total, 18 ACHD patients (15 with great anatomical complexity) received 21 CF-VADs. Six patients (median age 34 years) received seven percutaneous CF-VADs with a median duration of support of 20 days (3-44 days) with all patients survived to hospital discharge and two patients were bridged to durable CF-VADs. Fourteen patients (median age 38 years) received durable CF-VADs. Thirteen patients (93%) survived to hospital discharge and the median duration of support was 25.8 months (6.4-52.1 months). Estimated survival on durable CF-VAD at 1, 3, and 5 years was 84%, 72%, and 36%, respectively. Three patients were successfully bridged to transplantation. Device-related complications include cerebrovascular accident (n = 5), driveline infection (n = 3), device infection requiring chronic antibiotic therapy (n = 4), gastrointestinal bleeding (n = 6), and presumed pump thrombosis (n = 5). These results show percutaneous and durable CF-VADs can support ACHD patients with advanced HF.