Three-month outcomes after the implantation of two HeartMate 3 devices in total artificial heart configuration

BACKGROUND

Total artificial heart (TAH) implantation is a rarely performed procedure. Contrarily, left ventricular assist device (VAD) implantation is rather common in many centers. As transplantation is quantitatively limited cardiac replacement with artificial hearts is a viable alternative in the treatment of severe biventricular heart failure. An alternative to TAH is the implantation of two VADs in a TAH configuration. We hereby present the first multi-center study on 3-months outcomes of patients treated by cardiectomy and placement of two HeartMate 3s in a TAH configuration.

METHODS

We retrospectively investigated a cohort of 15 patients that underwent HM3-TAH-implantation at three international institutions. Follow-up was 3 months after implantation. Baseline, intra- and postoperative parameters as well as survival data and adverse events were collected.

RESULTS

A total of 1089 days on HM3-TAH were observed. Thirty-day survival after HM3-TAH implantation was 53% (8/15) and three month survival was 40% (6/15). The longest duration on device was 274 days. Causes of death were multi-organ failure, sepsis, and neurological adverse events. No technical complications were documented. Two patients remained on the device. Four patients (26%) were successfully bridged to transplantation.

CONCLUSIONS

The implantation of two HeartMate 3s in a TAH configuration is a last resort and off-label concept in cases of extreme biventricular heart failure. In a diligently selected patient cohort, HM3-TAH implantation is a feasible method to increase the chance of survival in a severely ill patient cohort and successfully bridge patients to heart transplantation that would otherwise have died.

HVAD to HeartMate 3 Left Ventricular Assist Device Exchange: Best Practices Recommendations

The HeartWare HVAD System (Medtronic) is a durable implantable left ventricular assist device that has been implanted in approximately 20,000 patients worldwide for bridge to transplant and destination therapy indications. In December 2020, Medtronic issued an Urgent Medical Device Communication informing clinicians of a critical device malfunction in which the HVAD may experience a delay or failure to restart after elective or accidental discontinuation of pump operation. Moreover, evolving retrospective comparative effectiveness studies of patients supported with the HVAD demonstrated a significantly higher risk of stroke and all-cause mortality when compared with a newer generation of a commercially available durable left ventricular assist device. Considering the totality of this new information on HVAD performance and the availability of an alternate commercially available device, Medtronic halted the sale and distribution of the HVAD System in June 2021. The decision to remove the HVAD from commercial distribution now requires the use of the HeartMate 3 left ventricular assist system (Abbott, Inc) if a patient previously implanted with an HVAD requires a pump exchange. The goal of this document is to review important differences in the design of the HVAD and HeartMate 3 that are relevant to the medical management of patients supported with these devices, and to assess the technical aspects of an HVAD-to-HeartMate 3 exchange. This document provides the best available evidence that supports best practices.

HVAD to HeartMate 3 left ventricular assist device exchange: Best practices recommendations

The HeartWare HVAD System (Medtronic) is a durable implantable left ventricular assist device that has been implanted in approximately 20,000 patients worldwide for bridge to transplant and destination therapy indications. In December 2020, Medtronic issued an Urgent Medical Device Communication informing clinicians of a critical device malfunction in which the HVAD may experience a delay or failure to restart after elective or accidental discontinuation of pump operation. Moreover, evolving retrospective comparative effectiveness studies of patients supported with the HVAD demonstrated a significantly higher risk of stroke and all-cause mortality when compared with a newer generation of a commercially available durable left ventricular assist device. Considering the totality of this new information on HVAD performance and the availability of an alternate commercially available device, Medtronic halted the sale and distribution of the HVAD System in June 2021. The decision to remove the HVAD from commercial distribution now requires the use of the HeartMate 3 left ventricular assist system (Abbott, Inc) if a patient previously implanted with an HVAD requires a pump exchange. The goal of this document is to review important differences in the design of the HVAD and HeartMate 3 that are relevant to the medical management of patients supported with these devices, and to assess the technical aspects of an HVAD-to-HeartMate 3 exchange. This document provides the best available evidence that supports best practices.

Five-year outcomes of patients supported with HeartMate 3: a single-centre experience

OBJECTIVES

The HeartMate 3 left ventricular assist device was first implanted in 2014 and received the Conformité Européenne mark in 2015. Since then, several trials demonstrated its high haemocompatibility associated with good survival and low adverse events rates. Herein, we report our institutional experience with patients supported with HeartMate 3 for 5 years.

METHODS

This prospective cohort study included patients receiving a HeartMate 3 implantation in 2014 as part of the HeartMate 3 Conformité Européenne Mark clinical trial. Patients had follow-up visits every 3 months while on left ventricular assist device support, and all patients completed the 5-year follow-up. The primary end point was survival at 5 years. Secondary end points included adverse events, health status and quality of life.

RESULTS

Eight patients (men: 75%) aged 59 years (min-max: 52-66 years) were enrolled. At 5 years, survival was 100%. Patients remained on support for a median time of 1825 days (min-max: 101-1825 days); 2 patients successfully received cardiac transplants. No right heart failure, haemolysis, pump thrombosis, pump malfunction or neurological events occurred in any patients. A driveline infection was observed in 6 patients (0.25 events/patient-year). Compared to baseline, a significant improvement in quality of life and in New York Heart Association functional class was noted after the implant and for the whole follow-up time. A slight decline in kidney function and in the 6-min walk test results occurred after 3 years.

CONCLUSIONS

This study reports the longest single-centre follow-up of the HeartMate 3, showing excellent haemocompatibility over time with high survival and low complication rates at 5 years.

Neutrophil injury and function alterations induced by high mechanical shear stress with short exposure time

High mechanical shear stresses (HMSS) can cause damage to blood, which manifests as morphologic changes, shortened life span, biochemical alterations, and complete rupture of blood cells and proteins, leading to the alterations of normal blood function. The aim of this study is to determine the state of neutrophil activation and function alterations caused by HMSS with short exposure time relevant to ventricular assist devices. Blood from healthy donors was exposed to three levels of HMSS (75Pa, 125Pa, and 175Pa) for a short exposure time (0.5 s) using our Couette-type blood-shearing device. Neutrophil activation (Mac-1, platelet-neutrophil aggregates) and surface expression levels of two key functional receptors (CD62L and CD162) on neutrophils were evaluated by flow cytometry. Neutrophil phagocytosis and transmigration were also examined with functional assays. Results showed that the expression of Mac-1 on neutrophils and platelet-neutrophil aggregates increased significantly while the level of CD62L expression on neutrophils decreased significantly after the exposure to HMSS. The Mac-1 expression progressively increased while the CD62L expression progressively decreased with the increased level of HMSS. The level of CD162 expression on neutrophils slightly increased after the exposure to HMSS, but the increase was not significant. The phagocytosis assay data revealed that the ability of neutrophils to phagocytose latex beads coated with fluorescently labeled rabbit IgG increased significantly with the increased level of HMSS. The transmigration ability of neutrophils slightly increased after the exposure to HMSS, but did not reach a significant level. In summary, HMSS with a short exposure time of 0.5 seconds could induce neutrophil activation, platelet-neutrophil aggregation, shedding of CD62L receptor, and increased phagocytic ability. However, the exposure to the three levels of HMSS did not cause a significant change in neutrophil transmigration capacity and shedding of CD162 receptor on neutrophils.

Expert Consensus Paper: Lateral Thoracotomy for Centrifugal Ventricular Assist Device Implant

BACKGROUND

The increasing prevalence of heart failure has led to the expanded use of left ventricle assist devices (VADs) for end-stage heart failure patients worldwide. Technological improvements witnessed the development of miniaturized VADs and their implantation through less traumatic non-full sternotomy approaches using a lateral thoracotomy (LT). Although adoption of the LT approach is steadily growing, a lack of consensus remains regarding patient selection, details of the surgical technique, and perioperative management. Furthermore, the current literature does not offer prospective randomized studies or evidence-based guidelines for LT-VAD implantation.

METHODS

A worldwide group of LT-VAD experts was convened to discuss these key topics openly. After a PubMed search and review with all authors, a consensus was reached and an expert consensus paper on LT-VAD implantation was developed.

RESULTS

This document aims to guide clinicians in the selection of patients suitable for LT approaches and preoperative optimization. Details of operative techniques are described, with an overview of hemisternotomy and bilateral thoracotomy approaches. A review of the best surgical practices for placement of the pump, inflow cannula, and outflow graft provides advice on the best surgical strategies to avoid device malpositioning while optimizing VAD function. Experts' opinions on cardiopulmonary bypass, postoperative management, and approaches for pump exchange and explant are presented. This review also emphasizes the critical need for multidisciplinary teams and specific training.

CONCLUSIONS

This expert consensus review provides a compact guide to LT for VAD implantation, from patient selection through intraoperative tips and postoperative management.

A Novel Hybrid Membrane VAD as First Step Toward Hemocompatible Blood Propulsion

Heart failure is a raising cause of mortality. Heart transplantation and ventricular assist device (VAD) support represent the only available lifelines for end stage disease. In the context of donor organ shortage, the future role of VAD as destination therapy is emerging. Yet, major drawbacks are connected to the long-term implantation of current devices. Poor VAD hemocompatibility exposes the patient to life-threatening events, including haemorrhagic syndromes and thrombosis. Here, we introduce a new concept of artificial support, the Hybrid Membrane VAD, as a first-of-its-kind pump prototype enabling physiological blood propulsion through the cyclic actuation of a hyperelastic membrane, enabling the protection from the thrombogenic interaction between blood and the implant materials. The centre of the luminal membrane surface displays a rationally-developed surface topography interfering with flow to support a living endothelium. The precast cell layer survives to a range of dynamically changing pump actuating conditions i.e., actuation frequency from 1 to 4 Hz, stroke volume from 12 to 30 mL, and support duration up to 313 min, which are tested both in vitro and in vivo, ensuring the full retention of tissue integrity and connectivity under challenging conditions. In summary, the presented results constitute a proof of principle for the Hybrid Membrane VAD concept and represent the basis for its future development towards clinical validation.

International experience using a durable, centrifugal-flow ventricular assist device for biventricular support

BACKGROUND

Heart transplantation is limited by the scarcity of suitable donors. Patients with advanced biventricular failure may require biventricular support to provide optimal cardiac output and end-organ perfusion. We highlight the outcomes of using the HeartWare HVAD System (HVAD) in a biventricular configuration.

METHODS

This retrospective study included patients implanted with HVAD as a biventricular assist device (BiVAD) between 2009 and 2017 at 12 participating centers. When used as a right ventricular assist device (VAD) (RVAD), the HVAD can be attached to the right ventricle (RV) or the right atrium (RA). Kaplan-Meier survival estimates were calculated comparing the 2 RVAD implant locations. Comparisons were also made between the timing of RVAD implantation (primary vs staged) on adverse event (AE) profiles and survival.

RESULTS

Among the 93 patients who were implanted with a HVAD BiVAD, Kaplan-Meier survivals at 1-year and 2-year were 56% and 47%, respectively. Survival was independent of the location of the HVAD RVAD implant or whether there was an interval between left VAD and RVAD implantation. The most common AEs were bleeding (35.5%), infection (25.8%), and respiratory failure (20.4%).

CONCLUSIONS

This study illustrated similar survival in patients receiving a primary or staged HVAD BiVAD implant at 1 year and 2 years. This study also established that the locations of the RVAD implant (RV or RA) result in similar AE profiles.

Statistics of heart failure and mechanical circulatory support in 2020

Heart failure is increasing in prevalence, with approximately 26 million patients affected worldwide. This represents a significant cause of morbidity and mortality. Statistics regarding heart failure patient age, hospitalization likelihood, and mortality differ significantly by country. Heart failure patients are typically classified by ejection fraction, with distinct phenotypes associated with reduced ejection fraction (rEF) or preserved ejection fraction (pEF). Heart failure has a significant financial impact related to hospitalization, medication, and procedural expenses. The costs of heart failure also extend to the reduced quality of life conferred by heart failure symptoms. Management of heart failure includes a variety of interventions, including mechanical circulatory support (MCS). MCS, including left ventricular assist devices (LVADs), right ventricular assist devices (RVADs) and extracorporeal membrane oxygenation (ECMO), has been a means of managing end stage heart failure. Given the relative scarcity of transplant organs, the utilization of MCS, particularly as a bridge to transplantation (BTT) has grown significantly. In this review, we discuss statistics related to heart failure and MCS. We evaluate how patients are classified and examine global trends and regional differences. We then address MCS therapies, the costs associated with heart failure, the impact of heart failure on patient quality of life, and data regarding morbidity and mortality.

Insight into Atrial Fibrillation in LVAD Patients: From Clinical Implications to Prognosis

The use of left ventricular assist devices (LVADs), whether for destination therapy or bridge to transplantation, has gained increasing validation in recent years in patients with advanced heart failure. Arrhythmias can be the most challenging variables in the management of such patients but the main attention has always been focused on ventricular arrhythmias given the detrimental impact on mortality. Nevertheless, atrial fibrillation (AF) is the most common rhythm disorder associated with advanced heart failure and may therefore characterize the LVADs' pre- and postimplantation periods. Indeed, the consequences of AF in the population suffering from standard heart failure may require a more comprehensive evaluation in the presence of or in sight of an LVAD, making the AF clinical management in these patients potentially complex. Several studies have been based on this subject with different and often conflicting results, leaving many questions unresolved. The purpose of this review is to summarize the main pieces of evidence about the clinical impact of AF in LVAD patients, underlining the main implications in terms of hemodynamics, thromboembolic risk, bleeding and prognosis. Therapeutic considerations about the clinical management of these patients are also made according to the latest evidence.

Outcome of patients receiving a continuous flow left ventricular assist device - a retrospective single center study

Objectives. We present the outcome of the first 80 patients receiving a continuous flow left ventricular assist device at Helsinki University Hospital between December 2011 and November 2018. Design. This was a single-center retrospective study. We describe our patient management in detail. The primary end-points were death, heart transplantation, or pump explant. Data was reported in accordance with the Interagency Registry for Mechanical Circulatory Support protocol. All patients receiving an assist device during the study period were included in the data analysis. Results. Mean patient age was 53 ± 12 years at implantation and 85% were male. Most patients suffered from dilated (48%), or ischemic (40%) cardiomyopathy. One-third of patients were bridged with venoarterial extracorporeal membrane oxygenation to assist device implantation. Implant strategy was bridge to transplant or bridge to decision in most patients (88%). Mean follow-up time on pump was 529 ± 467 days. Survival was 98, 92, 85, 79 and 71% at 1, 3, 12, 24 and 36 months, respectively. Most common causes of death were multi-organ failure, right heart failure, or stroke. Only three patients (4%) had suspected pump thrombosis, two of which resolved with medical treatment and one resulting in death. Pump exchange or explant were not performed in a single patient. Neurological events occurred in 18%, non-disabling stroke in 8%, and fatal stroke in 4% of the patients. The incidence of device-related infection was 10%. Conclusions. Survival rates were good, although one third of patients were bridged with temporary circulatory support. We report a high level of freedom from pump thrombosis, fatal stroke, and driveline infection.

Long-term follow-up of patients supported with the HeartWare left ventricular assist system

The aim of the present study is to report our long-term experience with the HeartWare Ventricular Assist System (HVAD). Between July 2009 and February 2018, a total of 103 patients (mean age 50.0 ± 14.4, range 28-74 years; 22 females) received HVAD implantation in a single center institution. A total of 26 (25.4%) patients were in cardiogenic shock preoperatively and received extracorporeal life support (ECLS) prior to HVAD implantation. The aim of left ventricular assist device (LVAD) implantation was bridge to transplantation (BT) in 59 (57.3%), destination therapy (DT) in 28 (27.2%), and bridge to decision in 16 (15.5%). There were 211.1 total patient years of support. Mean survival was 2.05 ± 2.14 years. Kaplan-Meier analysis showed an overall survival rate of 69.7%, 56.7%, 46.0%, and 25.0% at 1, 2, 4, and 8 years, respectively. A total of 23 patients (22.3%) died during the hospital stay. Of them 65.2% (15 patients) were preoperatively in cardiogenic shock (INTERMACS 1). Sub-analysis of the BT patients showed a mean survival of 2.45 ± 2.29 years with a survival rate of 85.1%, 75.1%, 67.2%, and 44.8% at 1, 2, 4, and 8 years, respectively. Among them, 20 patients received heart transplantation on follow-up. Mean survival of DT patients was 2.18 ± 1.91 years with a survival rate of 67.9%, 49.0%, and 25.1% at 1, 2, and 4 years, respectively. At latest follow-up in September 2018, 26 patients (25.24%) were still on LVAD. A total of five patients completed 6 years on LVAD, of them two were supported over 8 years. The most common adverse event reported was gastrointestinal bleeding requiring rehospitalization (0.161 EPPY). A total of 19 patients reported disabling stroke. Pump thrombosis was diagnosed in six patients (5.8%) (0.02 EPPY), of them four patients underwent pump exchange. To the best of our knowledge, this is the longest experience with HVAD reported so far. Patients supported with an HVAD show a satisfactory long-term survival. Further multicenter evaluations are needed to confirm these single-center results.

Long-Term Survival of Patients With Advanced Heart Failure Receiving an Left Ventricular Assist Device Intended as a Bridge to Transplantation: The Registry to Evaluate the HeartWare Left Ventricular Assist System

BACKGROUND

The paucity of available hearts for transplantation means that more patients remain on durable left ventricular support for longer periods of time. The Registry to Evaluate the HeartWare Left Ventricular Assist System was an investigator-initiated multicenter, prospective, single-arm database established to collect post-Conformité Européene mark clinical information on patients receiving the HeartWare ventricular assist device system as a bridge to transplantation. This registry represents the longest multicenter follow-up of primary left ventricular assist device outcomes.

METHODS

Data were collected on 254 commercial implants performed between February 2009 and March 2012 from 9 centers in Europe (7) and Australia (2). Patients were followed to device explant, heart transplantation, or death. The outcomes of patients through July/August 2018 were analyzed. Summary statistics were used to describe patient demographics, adverse events, length of support, and outcomes for this extended-term cohort.

RESULTS

A total of 122 patients were on support for >2 years, and 34 patients were on support for >5 years. Twenty nine patients are still alive on support (support ranging from 1213 to 3396 days), and 23 of those are on their original HeartWare ventricular assist device system. Kaplan-Meier survival through 7 years was 51%. Through 6 years, freedom from any stroke was 82%, while freedom from severely disabling stroke was 89%.

CONCLUSIONS

Low rates of heart transplant now require longer periods of left ventricular assist device support in patients. This analysis demonstrates that long-term support using a HeartWare ventricular assist device system offers survival of 51% through 7 years.

Der Herzinsuffizienzchirurg – Hausarzt und Herzchirurg

Bei der Therapie der terminalen Herzinsuffizienz handelt es sich um einen Wachstumsmarkt – sowohl für Kardiologen als auch für Herzchirurgen. Der besondere Reiz der Arbeit eines Herzinsuffizienzchirurgen besteht in der notwendigen Multidisziplinarität und der Tatsache, dass es nicht nur um den rein mechanistischen Zugang im Sinne der chirurgischen Therapie geht. Vielmehr macht ein Großteil der Arbeit die Vor- und Nachbehandlung aus, die meist durch den Chirurgen selbst ausgeführt wird. Umfassende herzchirurgische Kenntnisse sind ebenso unumgänglich wie das Verständnis kardiologischer und intensivmedizinischer Therapiekonzepte, um dem Patienten eine individuelle und sinnvolle Therapie anbieten zu können. Der vorliegende Beitrag bietet interessierten Kollegen einen Überblick über die Möglichkeiten und Anforderungen in diesem Teilgebiet der Herzchirurgie.

A novel risk score to predict survival in advanced heart failure due to cardiac amyloidosis

BACKGROUND

Cardiac amyloidosis, caused by deposition of immunoglobulin light chains (AL) or transthyretin (ATTR), carries a poor prognosis. Established risk scores for amyloidosis may not predict outcomes in those patients who develop advanced heart failure and who are potential candidates for heart transplantation. Here, we aimed to identify predictive parameters for patients with severe heart failure due to amyloidosis.

METHODS

Out of > 1000 patients with cardiac amyloidosis (AL or ATTR) admitted to our centre between September 1998 and January 2016, a cohort of 120 patients with a complete cardiac assessment at diagnosis, including right heart catheterization, echocardiography and biomarkers, was analysed retrospectively in this study. Primary endpoint was all-cause mortality. We performed univariate and multivariate Cox regression analysis, generated risk scores to predict outcomes in AL and ATTR amyloidosis and compared those to established risk models for amyloidosis.

RESULTS

In the Cox multivariate model, high-sensitivity troponin T (hsTnT; hazard ratio (HR) 1.003; confidence interval (CI) 1.001-1.005; p = 0.009) and mean pulmonary artery pressure (HR 1.061; CI 1.024-1.100; p = 0.001) were found to significantly and independently predict outcomes for AL amyloidosis, whereas QRS duration (HR 1.021; CI 1.004-1.039; p = 0.013), hsTnT (HR 1.021; CI 1.006-1.036; p = 0.006) and N-terminal pro-brain natriuretic peptide (HR 1.0003; CI 1.0001-1.0004; p = 0.002) were the best predictors for ATTR amyloidosis. A simple risk score ("HeiRisk") including these parameters for AL and ATTR allowed a more precise risk stratification in our patient population compared to established risk models.

CONCLUSIONS

Risk stratification for cardiac amyloidosis with the newly developed "HeiRisk" score may be superior to other staging systems for patients with advanced heart failure due to amyloid cardiomyopathy.

Long-Term Left Ventricular Assist Device (LVAD): A Rare Case of 10 Years' Support and Follow-Up

Patient: Male, 66

Final Diagnosis: Ischemic cardiomyopathy

Symptoms: Angina pectoris • dyspnoea

Medication: —

Clinical Procedure: —

Specialty: Surgery

Left ventricular assist device as destination therapy for end stage heart failure: the right time for the right patients

PURPOSE OF REVIEW

Cardiac transplantation is the gold standard treatment for patients with end-stage heart failure. Unfortunately, the demand for donor organs far outstrips the number of available hearts. Therefore, not all patients who can benefit from this therapy are even listed for transplant. Once destination therapy was approved for the long-term support of nontransplant eligible patients, it was felt that the number of durable ventricular assist device (VAD) implants would increase. It was not until the current generation continuous-flow VADs became available that the number of DT-VAD implants grew significantly. The purpose of this manuscript is to review current indications and outcomes following durable VAD implant for destination therapy.

RECENT FINDINGS

In 2014, DT-VADs accounted for 46% of all implants. A propensity-matched analysis showed that 1-year and 2-year survival rates were similar between LVADs and cardiac transplantation. Likely because of their younger age and lack of comorbidities, survival after VAD implant in transplant eligible patients remains higher than after DT-VAD implant. However, the survival differences are narrowing. Although the rates of LVAD-related adverse events continue to be high, studies such as the PREVENT trial have proven that strict adherence to management protocols can reduce event rates.

SUMMARY

Improvements in device technology as well as patient selection and management have led to improved medium term (2-4 years) survival after VAD implant in nontransplant eligible patients. We anticipate that this technology will soon be a reasonable and competitive alternative to conventional heart transplantation.

Initial experience with telemonitoring in left ventricular assist device patients

Background

Left ventricular assist devices (LVAD) are increasingly used in patients with end stage heart failure. The HeartAssist 5 and aVAD LVADs offer telemetric monitoring capabilities. Here we report our initial single centre experience with the largest telemonitoring cohort of LVAD patients.

Methods

Eleven patients (9 males) received a telemonitoring-capable LVAD and were included in our telemonitoring cohort. Waveforms and alarm data were obtained from the telemonitoring system and hospital records were reviewed for clinical data.

Results

Mean age at LVAD implantation was 59±5.1 years (mean ± standard deviation). Seven patients had non-ischemic cardiomyopathy and 4 patients had ischemic cardiomyopathy. Median LVEF at implant was 16% (IQR, 15-20%). The total follow-up time was 2,438 patient-days. A total of 6,216 alarm messages were generated in 11 patients. Most common were low flow alarms due to hypovolemia, followed by low flow alarms because of suspected pump thrombosis. One patient died during follow-up, one received a cardiac transplant and one had the LVAD explanted because of pump thrombosis. Pump thrombosis was suspected in 5 patients with 8 episodes of sudden flow decreases and laboratory signs of haemolysis.

Conclusions

Real-time telemonitoring of LVAD pump flow, motor speed and power consumption is a promising tool in the follow-up of LVAD recipients. Trending pump flow over hours or days can assist in the early detection of complications, especially flow reductions due to hypovolemia and LVAD thrombosis. Further studies are warranted to delineate the impact of remote monitoring on patients' prognosis.

Long-term evaluation of a fully magnetically levitated circulatory support device for advanced heart failure-two-year results from the HeartMate 3 CE Mark Study

AIM

This study aimed to assess safety and outcomes of patients, 2 years after implantation with the HeartMate 3 Left Ventricular Assist System.

METHODS AND RESULTS

This study included 50 adults with New York Heart Association (NYHA) class IIIB or IV symptoms or American College of Cardiology/American Heart Association stage D heart failure with an ejection fraction ≤25% and a cardiac index ≤2.2 L/min/m² without inotropes, or inotrope-dependent with optimal medical management, or listed for heart transplant. The median duration of left ventricular assist device support was 694 days (range: 19-833 days). At baseline, cardiac index was 1.8 ±0.5 L/min/m² , 58% of patients were receiving inotropes, and 92% were INTERMACS profiles 2-4. At 2 years, Kaplan-Meier survival was 74 ±6%, 5 (10%) patients were transplanted, and 32 patients (64%) remain with support. Adverse event rates include bleeding requiring surgery (16%), gastrointestinal bleeding (20%), driveline infection (24%), ischaemic stroke (16%), haemorrhagic stroke (8%), right heart failure (14%), and outflow graft thrombosis (2%). Notably, no haemolysis, pump thrombosis, or pump malfunction events occurred. At 2 years, 47% of patients remained in NYHA class I and 41% in NYHA class II (P <0.0001). From baseline to 2 years, the mean six-minute walk distance increased from 239 m to 347 m (P <0.0001), and the mean EQ-5D quality of life score improved from 48.2 to 70.6 (P < 0.0001).

CONCLUSIONS

Two years post-HeartMate 3 implantation, results show expected and acceptable survival, enhanced haemocompatibility, improved patient functional status and quality of life. This corroborates the success of HeartMate 3 since its first-in-man implantation case in Germany. ClinicalTrials.gov: NCT02170363.

Left ventricular assist device (LVAD) program in Chile: first successful experience in South America

Background

The need to have a variety of tools to deal with end-stage heart failure (ES-HF), along with the limited heart transplantation availability encouraged us to create a pilot Left ventricular assist device (LVAD) program in a public health care system hospital in Chile.

Methods

A retrospective analysis of the first nine patients of an ongoing LVAD program initiated on August 2013 was performed, completing an average of 30 months of follow-up. The most important events regarding to morbidity and mortality are described.

Results

Nine patients with ES-HF underwent LVAD implantation surgery; one of them died 23 days after surgery and another died after 11 months. One patient successfully underwent heart transplantation after 16 months of HeartWare ventricular assist device (HVAD) support; the other six patients remain in the program and have an average follow-up of 846 days at the time of this study (range, 23-1,481 days). The survival rate at 6, 12 and 18 months follow-up was 89%, 78% and 78% respectively.

Conclusions

This new pioneering LVAD program in Chile has been successful and now constitutes a vital adjunct to all who work in heart transplantation and ES-HF programs. It offers an effective therapeutic alternative when there is a severe donor shortage, in cases of atypical blood types, emergencies, exceptional cases with contraindication for heart transplantation or when there is important donor-receiver size mismatch.

Argatroban administration as therapy for thrombosis in patients with continuous-flow ventricular assist devices

Background

Device thrombosis is one of the main complications in left ventricular assist devices (LVAD) therapy and remains a challenging issue. Data on device thrombosis management, especially on the application of direct thrombin inhibitors such as argatroban, is limited and a consensus on thrombosis management has not yet been established.

Methods

In this study we analysed retrospective clinical data obtained from 26 patients on VAD therapy who received argatroban for suspected VAD thrombosis, between April, 2012 and February, 2017.

Results

Thirteen patients (50%) showed resolution of thrombus after argatroban therapy. Eight of 26 patients (30.8%) were free of thrombotic events 90 days after discharge. Argatroban therapy was unsuccessful in 13 patients of the study cohort, leading to subsequent VAD-exchange. Six of 13 patients with first VAD-exchange had no thrombotic events 90 days after discharge. Six patients (23.1%) suffered from bleeding, especially gastrointestinal bleeding. No hemorrhagic strokes were observed. Three patients (11.5%) did not survive the follow-up period.

Conclusions

Argatroban appears to be an alternative to other pharmacological treatment options in VAD thrombosis. Efficacy and safety characteristics are acceptable, but further investigation on larger populations is necessary.

Living Without a Pulse: The Vascular Implications of Continuous-Flow Left Ventricular Assist Devices

Pulsatility seems to have a teleological role because evolutionary hierarchy favors higher ordered animals with more complex, multichamber circulatory systems that generate higher pulse pressure compared with lower ordered animals. Yet despite years of such natural selection, the modern generation of continuous-flow left ventricular assist devices (CF-LVADs) that have been increasingly used for the last decade have created a unique physiology characterized by a nonpulsatile, nonlaminar blood flow profile with the absence of the usual large elastic artery Windkessel effect during diastole. Although outcomes and durability have improved with CF-LVADs, patients supported with CF-LVADs have a high rate of complications that were not as frequently observed with older pulsatile devices, including gastrointestinal bleeding from arteriovenous malformations, pump thrombosis, and stroke. Given the apparent fundamental biological role of the pulse, the purpose of this review is to describe the normal physiology of ventricular-arterial coupling from pulsatile flow, the effects of heart failure on this physiology and the vasculature, and to examine the effects of nonpulsatile blood flow on the vascular system and potential role in complications seen with CF-LVAD therapy. Understanding these concomitant vascular changes with CF-LVADs may be a key step in improving patient outcomes as modulation of pulsatility and flow characteristics may serve as a novel, yet simple, therapy for reducing complications.

Left ventricular assist device therapy: the Kuwait experience

Background

Heart Failure is an epidemic with a current prevalence of over 5.8 million patients in the USA and almost 23 million patients worldwide, with high associated mortality risks. The severe shortage of donor organs for cardiac transplants and increasing number of heart failure patients has led to the increasing popularity of left ventricular assist device (LVAD) therapy for treatment of end-stage heart failure patients. This paper describes our initial clinical experience with LVAD therapy of heart failure patients at our clinic.

Methods

Ten patients (eight males and two females) with a mean age of 48 years (range, 14-68 years) were implanted with LVADs as bridge to transplantation (BT) or destination therapy (DT) at our clinic between January 2015 and October 2017.

Results

Preliminary results were very promising with 0% 30-day mortality rates and no major surgical complications or LVAD thrombosis.

Conclusions

Such results of LVAD implantation in Kuwait indicate the feasibility of establishing De Novo LVAD programs in low volume LVAD centers (≤10 implants/year) with promising results and offer a new era of hope for treating advanced heart failure patients.

Clinical overview of the HVAD: a centrifugal continuous-flow ventricular assist device with magnetic and hydrodynamic bearings including lateral implantation strategies

Growing worldwide incidences of end-stage heart failure and declining rates of cardiac transplants have given rise to the need for alternative treatment options, based on mechanical circulatory support (MCS) devices such as left ventricular assist devices (LVADs). Technologically advanced LVADs such as the HVAD^® (HeartWare^®, Medtronic) facilitate safe and efficient treatment of heart failure patients with reduced post-operative complications, which is attributed to their considerably miniaturized size. This also facilitates the development and implementation of novel, minimally-invasive surgical techniques. The HVAD is a centrifugal pump, manufactured by HeartWare Inc., (Framingham, MA, USA) and subsequently by Medtronic Inc., (Minnesota, MN, USA), and has been approved for clinical application after receiving the CE Mark approval in 2008 and the FDA approval in 2012. Current research efforts are focused on further miniaturization alongside optimization of electronic and software controllers as well as implementation of the transcutaneous energy transfer (TET) technology. Salient features of the HVAD pump technology, clinical applications and future optimization strategies have been discussed in this article.

An original valveless artificial heart providing pulsatile flow tested in mock circulatory loops

PURPOSE

We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population.

METHODS

The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk.Mock circulatory system: The device pumps a 37% glycerin solution through 2 parallel circuits, simulating the pulmonary and systemic circulations. Flow rates are acquired with a magnetic inductive flowmeter, while pressure sensors collect pressure in the left and right outflow and inflow tracts.In vitro test protocol: The pump is run at speeds ranging from 20 to 180 ejections per minute. The waveform of the pressure generated at the inflow and outflow of the 4 chambers and the flow rate in the systemic circulation are measured.

RESULTS

At an ejection rate of 178 min-1, the RollingHeart pumps 5.3 L/min for a systemic maximal pressure gradient of 174 mmHg and a pulmonary maximal pressure gradient of 75 mmHg. The power input was 14 W, corresponding to an efficiency of 21%.

CONCLUSIONS

The RollingHeart represents a new approach in the domain of total artificial heart. This preliminary study endorses the feasibility of a single valveless device acting as a total artificial heart.

[Indications and strategies in mechanical circulatory support : Rise of the machines?]

Terminal heart failure is an emerging problem with a continuously growing number of diseased patients worldwide. Because of the limited number of donor hearts, mechanical circulatory support is increasingly becoming an integral part of surgical treatment for end-stage heart failure, especially in patients deemed for destination therapy. Accurate patient selection, appropriate indication, and the optimal implantation time point guarantee a good outcome for these patients. This review article gives a systematic overview of the possible indication settings and treatment strategies for various patient groups in need of mechanical circulatory support.

New role of ventricular assist devices as bridge to transplantation: European perspective

PURPOSE OF REVIEW

Progress of ventricular assist devices (VAD) technology led to improved survival and apparently low morbidity. However, from the European perspective, updated analysis of EUROMACS reveals a somewhat less impressive picture with respect to mortality and morbidity.

RECENT FINDINGS

We describe the great demand of cardiac allografts versus the lack of donors, which is larger in Europe than in the United States. Technical progress of VADs made it possible to work out a modern algorithm of bridge-to-transplant, which is tailored to the need of the particular patient. We analyze the burden of patients undergoing bridge-to-transplant therapy. They are condemned to an intermediate step, coupled with additional major surgery and potential adverse events during heart transplantation.

SUMMARY

Based on current registry data, we do have to question the increasingly popular opinion, that the concept of heart transplantation is futureless, which seems to be for someone who treats and compares both patients (VAD and heart transplantation) in daily practice, questionable. Up to now, left ventricular assist device therapy remains a bridge to a better future, which means a bridge to technical innovations or to overcome the dramatic lack of donors in Europe.