Twelfth Interagency Registry for Mechanically Assisted Circulatory Support Report: Readmissions After Left Ventricular Assist Device

Effect of impeller rotational phase on the FDA blood pump velocity fields

BACKGROUND

The Food and Drug Administration (FDA) blood pump is an open-source benchmark cardiovascular device introduced for validating computational and experimental performance analysis tools. The time-resolved velocity field for the whole impeller has not been established, as is undertaken in this particle image velocimetry (PIV) study. The level of instantaneous velocity fluctuations is important, to assess the flow-induced rotor vibrations which may contribute to the total blood damage.

METHODS

To document these factors, time-resolved two-dimensional PIV experiments were performed that were precisely phase-locked with the impeller rotation angle. The velocity fields in the impeller and in the volute conformed with the previous single blade passage experiments of literature.

RESULTS

Depending on the impeller orientation, present experiments showed that volute outlet nozzle flow can fluctuate up to 34% during impeller rotation, with a maximum standard experimental uncertainty of 2.2%. Likewise, the flow fields in each impeller passage also altered in average 33.5%. Considerably different vortex patterns were observed for different blade passages, with the largest vortical structures reaching an average core radii of 7 mm. The constant volute area employed in the FDA pump design contributes to the observed velocity imbalance, as illustrated in our velocity measurements.

CONCLUSIONS

By introducing the impeller orientation parameter for the nozzle flow, this study considers the possible uncertainties influencing pump flow. Expanding the available literature data, analysis of inter-blade relative velocity fields is provided here for the first-time to the best of our knowledge. Consequently, our research fills a critical knowledge gap in the understanding of the flow dynamics of an important benchmark cardiovascular device. This study prompts the need for improved hydrodynamic designs and optimized devices to be used as benchmark test devices, to build more confidence and safety in future ventricular assist device performance assessment studies.

Current status and future directions in pediatric ventricular assist device

A ventricular assist device (VAD) is a form of mechanical circulatory support that uses a mechanical pump to partially or fully take over the function of a failed heart. In recent decades, the VAD has become a crucial option in the treatment of end-stage heart failure in adult patients. However, due to the lack of suitable devices and more complicated patient profiles, this therapeutic approach is still not widely used for pediatric populations. This article reviews the clinically available devices, adverse events, and future directions of design and implementation in pediatric VADs.

The International Society for Heart and Lung Transplantation (ISHLT): 2024 infection definitions for durable and acute mechanical circulatory support devices

Infections remain a significant concern in patients receiving mechanical circulatory support (MCS), encompassing both durable and acute devices. This consensus manuscript provides updated definitions for infections associated with durable MCS devices and new definitions for infections in acute MCS, integrating a comprehensive review of existing literature and collaborative discussions among multidisciplinary specialists. By establishing consensus definitions, we seek to enhance clinical care, facilitate consistent reporting in research studies, and ultimately improve outcomes for patients receiving MCS.

Optimizing Triage of Ambulatory Patients With Advanced Heart Failure: 2-Year Outcomes From REVIVAL

BACKGROUND

Left ventricular assist device (LVAD) use remains uncommon in advanced heart failure (HF) patients not dependent on inotropes.

OBJECTIVES

Before considering a randomized trial comparing a strategy of earlier use of LVAD to continued medical therapy, a better understanding is needed of the clinical trajectory of ambulatory patients with advanced systolic HF on optimal guideline-directed medical therapy (GDMT).

METHODS

REVIVAL enrolled 400 patients with advanced ambulatory systolic HF, ≥1 HF mortality risk marker (≥2 HF hospitalizations past year; or HF hospitalization and high natriuretic peptide; or no HF hospitalizations but low peak oxygen consumption, 6-minute walk, serum sodium, HF survival score or Seattle HF model predicted survival), and no LVAD contraindication at 21 LVAD centers from July 2015 to June 2016. Patients were followed for 2 years or until a primary outcome (death, durable ventricular assist device, or urgent transplant). Clinical outcomes and health-related quality of life were evaluated.

RESULTS

Mean baseline left ventricular ejection fraction was 21%, median 6-minute walk was 341 m, and 92% were Interagency Registry for Mechanically Assisted Circulatory Support profiles 5 to 7. Adherence to GDMT and electrical device therapies was robust. Composite primary outcome occurred in 22% and 37% at 1 and 2 years, with death alone in 8% and 16%, respectively. Patients surviving for 2 years maintained GDMT intensity and had no decline in health-related quality of life.

CONCLUSION

Structured, serial follow-up at programs with expertise in caring for advanced ambulatory systolic HF patients facilitates triage for advanced therapies. Better strategies are still needed to avoid deaths in a small but significant group of patients who die without advanced therapies. REVIVAL patients not selected for VAD or transplant have robust survival and patient-reported outcomes, which challenges advocacy for earlier VAD implantation. (Registry Evaluation of Vital Information for VADs in Ambulatory Life [REVIVAL]; NCT01369407).

Unplanned hospital readmissions following HeartMate 3 implantation: Readmission rates, causes, and impact on survival

BACKGROUND

Hospital readmissions following left ventricular assist device (LVAD) remain a frequent comorbidity, associated with decreased quality of life and increased resources utilization. This study sought to determine causes, predictors, and impact on survival of hospitalizations during HeartMate 3 (HM3) support.

METHODS

All patients implanted with HM3 between November 2014 to December 2019 at Columbia University Irving Medical Center were consecutively enrolled in the study. Demographics and clinical characteristics from the index admission and the first outpatient visit were collected and used to estimate 1-year and 900-day readmission-free survival and overall survival. Multivariable analysis was performed for subsequent readmissions.

RESULTS

Of 182 patients who received a HM3 LVAD, 167 (92%) were discharged after index admission and experienced 407 unplanned readmissions over the median follow up of 727 (interquartile range (IQR): 410.5, 1124.5) days. One-year and 900-day mean cumulative number of all-cause unplanned readmissions was 0.43 (95%CI, 0.36, 0.51) and 1.13 (95%CI, 0.99, 1.29). The most frequent causes of rehospitalizations included major infections (29.3%), bleeding (13.2%), device-related (12.5%), volume overload (7.1%), and other (28%). One-year and 900-day survival free from all-cause readmission was 38% (95%CI, 31-46%) and 16.6% (95%CI, 10.3-24.4%). One-year and 900-day freedom from 2, 3, and ≥4 readmissions were 60.7%, 74%, 74.5% and 26.2%, 33.3%, 41.3%. One-year and 900-day survival were unaffected by the number of readmissions and remained >90%. Male sex, ischemic etiology, diabetes, lower serum creatinine, longer duration of index hospitalization, and a history of readmission between discharge and the first outpatient visit were associated with subsequent readmissions.

CONCLUSIONS

Unplanned hospital readmissions after HM3 are common, with infections and bleeding accounting for the majority of readmissions. Irrespective of the number of readmissions, one-year survival remained unaffected.

Pumping for Two: Pregnancy in Patients Supported With a Left Ventricular Assist Device

This review discusses the challenges and outcomes associated with pregnancy during left ventricular assist device (LVAD) support. Women account for a third of the heart failure population in the United States. Left ventricular assist devices have emerged as a safe and effective treatment option for patients with advanced heart failure. Pregnancy during LVAD support can occur, and it presents significant risks to both mother and fetus, including hemodynamic stress, thrombotic events, medication-associated teratogenicity, and uterine impingement. This literature review identified 10 cases of confirmed pregnancy during LVAD support, of which eight resulted in successful births. Maternal and fetal mortality occurred in one case, and there was a spontaneous abortion in one case. The review highlights the importance of a multidisciplinary approach, promotion of shared decision-making, thoughtful anticoagulation, adjustment of LVAD speed, and medication optimization to maintain hemodynamic support during pregnancy. Hemodynamic changes during pregnancy include increased cardiac output, heart rate, and plasma volume, as well as decreased systemic vascular resistance, which can impact LVAD support. Despite reduced pulsatility in LVAD-supported patients, ovulation and reproductive capacity might be preserved, and viable pregnancies may be achieved with appropriate management. The review provides insights into the risks and considerations for a viable pregnancy during LVAD support, including the need for ongoing research to inform joined decision-making.

Hospital Readmissions in Patients Supported with Durable Centrifugal-Flow Left Ventricular Assist Devices

Background: Centrifugal-flow left ventricular assist devices (CF-LVADs) have improved morbidity and mortality for their recipients. Hospital readmissions remain common, negatively impacting quality of life and survival. We sought to identify risk factors associated with hospital readmissions among patients with CF-LVADs. Methods: Consecutive patients receiving a CF-LVAD between February 2011 and March 2021 were retrospectively evaluated using prospectively maintained institutional databases. Hospital readmissions within three years post-LVAD implantation were dichotomized into heart failure (HF)/LVAD-related or non-HF/LVAD-related readmissions. Multivariable Cox regression models augmented using a machine learning algorithm, the least absolute shrinkage and selection operator (LASSO) method, for variable selection were used to estimate associations between HF/LVAD-related readmissions and pre-, intra- and post-operative clinical variables. Results: A total of 204 CF-LVAD recipients were included, of which 138 (67.7%) had at least one HF/LVAD-related readmission. HF/LVAD-related readmissions accounted for 74.4% (436/586) of total readmissions. The main reasons for HF/LVAD-related readmissions were major bleeding, major infection, HF exacerbation, and neurological dysfunction. Using pre-LVAD variables, HF/LVAD-related readmissions were associated with substance use, previous cardiac surgery, HF duration, pre-LVAD inotrope dependence, percutaneous LVAD/VA-ECMO support, LVAD type, and the left ventricular ejection fraction in multivariable analysis (Harrell's concordance c-statistic; 0.629). After adding intra- and post-operative variables in the multivariable model, LVAD implant hospitalization length of stay was an additional predictor of readmission. Conclusions: Using machine learning-based techniques, we generated models identifying pre-, intra-, and post-operative variables associated with a higher likelihood of rehospitalizations among patients on CF-LVAD support. These models could provide guidance in identifying patients with increased readmission risk for whom clinical strategies to mitigate this risk may further improve LVAD recipient outcomes.

Evaluation of the Hemocompatibility of the Direct Oral Anticoagulant Apixaban in Left Ventricular Assist Devices: The DOAC LVAD Study

BACKGROUND

Patients receiving left ventricular assist device (LVAD) support require long-term anticoagulation to reduce the risk of thromboembolic complications. Apixaban is a direct oral anticoagulant that has become first-line therapy; however, its safety in LVAD recipients has not been well described.

OBJECTIVES

This study sought to investigate whether, in patients with a fully magnetically levitated LVAD, treatment with apixaban would be feasible and comparable with respect to safety and freedom from the primary composite outcome of death or major hemocompatibility-related adverse events (HRAEs) (stroke, device thrombosis, major bleeding, aortic root thrombus, and arterial non-central nervous system thromboembolism) as compared with treatment with warfarin.

METHODS

The DOAC LVAD (Evaluation of the Hemocompatibility of the Direct Oral Anti-Coagulant Apixaban in Left Ventricular Assist Devices) trial was a phase 2, open label trial of LVAD recipients randomized 1:1 to either apixaban 5 mg twice daily or warfarin therapy. All patients were required to take low-dose aspirin. Patients were followed up for 24 weeks to evaluate the primary composite outcome.

RESULTS

A total of 30 patients were randomized: 14 patients to warfarin and 16 patients to apixaban. The median patient age was 60 years (Q1-Q3: 52-71 years), and 47% were Black patients. The median time from LVAD implantation to randomization was 115 days (Q1-Q3: 56-859 days). At 24 weeks, the primary composite outcome occurred in no patients receiving apixaban and in 2 patients (14%) receiving warfarin (P = 0.12); these 2 patients experienced major bleeding from gastrointestinal sources.

CONCLUSIONS

Anticoagulation with apixaban was feasible in patients with an LVAD without an excess of HRAEs or deaths. This study informs future pivotal clinical trials evaluating the safety and efficacy of apixaban in LVAD recipients. (Evaluation of the Hemocompatibility of the Direct Oral Anti-Coagulant Apixaban in Left Ventricular Assist Devices [DOAC LVAD]; NCT04865978).

Prognostic Implications of Delirium After Left Ventricular Assist Device Implantation: A Retrospective Study

BACKGROUND

In critically ill patients, delirium is a prognostic indicator of morbidity and mortality.

OBJECTIVE

This study investigates the impact of a delirium diagnosis on outcomes after left ventricular assist device (LVAD) implantation.

METHODS

This retrospective study included all adult patients who received LVADs at our institution between January 2016 and December 2020. We compared preimplantation characteristics between the two groups, with and without a diagnosis of delirium, and compared their outcomes, including 1-month, 6-month, and in-hospital mortality, as well as reintubation rate, length of stay, discharge disposition, and readmission rates.

RESULTS

In total, 361 patients (26.7% women and 75.8% African American) received durable LVADs. Ninety-four patients (26.1%) were diagnosed with delirium during the index admission. Preimplantation demographic characteristics, past medical and psychiatric conditions, Interagency Registry for Mechanically Assisted Circulatory Support Profile, and laboratory values did not differ between the two groups with and without a diagnosis of delirium; older age (59 vs 56; P = 0.03) was associated with delirium. Delirium diagnosis was associated with higher 1-month (P = 0.007), 6-month (P = 0.004), and in-hospital mortality (P < 0.001), unplanned reintubations (P < 0.001), and a lower likelihood of discharge home (P = 0.03). Total hospital and intensive care unit length of stay were higher in patients with a diagnosis of delirium, though these results were not statistically significant. Readmission to the hospital after index admission was quicker in patients with a diagnosis of delirium, but this result was not statistically significant.

CONCLUSIONS

In this study, a diagnosis of delirium during the LVAD implantation admission was associated with higher mortality, adverse postsurgical outcomes, and unfavorable discharge dispositions. Future prospective research is needed to validate the prognostic implications of delirium in both the short and long term. Additionally, there is a need to identify modifiable risk factors associated with delirium to promote early diagnosis and implement evidence-based management strategies to enhance outcomes within this population.

Evaluation of enoxaparin for bridging of warfarin in outpatients with left ventricular assist devices (LVADs)

BACKGROUND

Patients with left ventricular assist devices (LVADs) require systemic anticoagulation. The use of enoxaparin for bridging to warfarin remains understudied in this population.

METHODS

This single-center retrospective study was performed to characterize enoxaparin use and associated thrombotic and bleeding outcomes in adult outpatients with LVADs from January 2018 to July 2021.

RESULTS

Fifty-four enoxaparin bridging events were evaluated in 49 patients. Most patients with HeartMate II (HM2) and HeartWare (HVAD) devices received enoxaparin dosed 1 mg/kg every 12 h. In patients with HeartMate 3 (HM3) devices, an equal number of patients received 0.5 mg/kg every 12 h and 1 mg/kg every 12 h, with a smaller subset receiving intermediate doses. The median duration of bridging was 6 days (4-8 [IQR]). One major bleeding event required discontinuation of enoxaparin and hospitalization in a patient with an HM3 device. Thrombotic events occurred in four patients with two incidents of pump thrombosis requiring pump exchange and two ischemic strokes. All thrombotic events occurred in patients with HVAD or HM2 devices.

CONCLUSION

These results suggest that enoxaparin bridging in LVAD patients was well-tolerated with low bleeding and thrombotic rates, particularly with the HM3 device.

Gastrointestinal bleeding following Heartmate 3 left ventricular assist device implantation: The Michigan Bleeding Risk Model

BACKGROUND

Gastrointestinal bleeding (GIB) results in frequent hospitalizations and impairs quality of life in durable left ventricular assist device (LVAD) recipients. Anticipation of these events before implantation could have important implications for patient selection and management.

METHODS

The study population included all adult HeartMate 3 (HM3) primary LVAD recipients enrolled in the STS Intermacs registry from January 2017 to December 2020. Using multivariable modeling methodologies, we investigated the relationships between preimplantation characteristics and postimplant bleeding, bleeding and death, and additional bleeding episodes on subsequent bleeding episodes and created a risk score to predict the likelihood of post-LVAD GIB based solely on preimplantation factors.

RESULTS

Of 6,425 patients who received an HM3 LVAD, 1,010 (15.7%) patients experienced GIB. Thirteen preimplantation factors were independent predictors of post-LVAD GIB. A risk score was created from these factors and calculated for each patient. By 3 years postimplant, GIB occurred in 11%, 26%, and 43% of low-, medium- and high-risk patients, respectively. Experiencing 1 post-LVAD GIB event was associated with an increased risk for further GIB events, with 33.9% of patients experiencing at least 1 recurrence. While post-LVAD GIB was associated with mortality, there was no relationship between number of GIB events and death.

CONCLUSIONS

The Michigan Bleeding Risk Model is a simple tool, which facilitates the prediction of post-LVAD GIB in HM3 recipients using 13 preimplant variables. The implementation of this tool may help in the risk stratification process and may have therapeutic and clinical implications in HM3 LVAD recipients.

Clinical Trial Diversity, Equity, and Inclusion: Roadmap of the Cardiothoracic Surgical Trials Network

BACKGROUND

There is a recognized lack of diversity among patients enrolled in cardiovascular interventional and surgical trials. Diverse patient representation in clinical trials is necessary to enhance generalizability of findings, which may lead to better outcomes across broader populations. The Cardiothoracic Surgical Trials Network (CTSN) recently developed a plan of action to increase diversity among participating investigators and trial participants and is the focus of this review.

METHODS

A review of literature and enrollment data from CTSN trials was conducted.

RESULTS

CTSN completed more than a dozen major clinical trials (2008-2022), enrolling >4000 patients, of whom 30% were women, 11% were non-White, and 5.6% were Hispanic. CTSN also completed trials of hospitalized patients with coronavirus disease 2019, wherein enrollment was more diverse, with 42% women, and 58% were Asian, Black, Hispanic, or from another underrepresented racial group. The discrepancy in diversity of enrollment between cardiac surgery trials and coronavirus disease trials highlights the need for a more comprehensive understanding of (1) the prevalence of underlying disease requiring cardiac interventions across broad populations, (2) differences in access to care and referral for cardiac surgery, and (3) barriers to enrollment in cardiac surgery trials.

CONCLUSIONS

Committed to diversity, CTSN's multifaceted action plan includes developing site-specific enrollment targets, collecting social determinants of health data, understanding reasons for nonparticipation, recruiting sites that serve diverse populations, emphasizing greater diversity among clinical trial teams, and implicit bias training. The CTSN will prospectively assess how these interventions influence enrollment as we work to ensure trial participants are more representative of the communities we serve.

Sex-Linked Differences in Cardiac Atrophy After Mechanical Unloading Induced by Heterotopic Heart Transplantation

No information is available about sex-related differences in unloading-induced cardiac atrophy. We aimed to compare the course of unloading-induced cardiac atrophy in intact (without gonadectomy) male and female rats, and in animals after gonadectomy, to obtain insight into the influence of sex hormones on this process. Heterotopic heart transplantation (HT((x)) was used as a model for heart unloading. Cardiac atrophy was assessed as the weight ratio of heterotopically transplanted heart weight (HW) to the native HW on days 7 and 14 after HTx in intact male and female rats. In separate experimental groups, gonadectomy was performed in male and female recipient animals 28 days before HT(x) and the course of cardiac atrophy was again evaluated on days 7 and 14 after HT(x). In intact male rats, HT(x) resulted in significantly greater decreases in whole HW when compared to intact female rats. The dynamics of the left ventricle (LV) and right ventricle (RV) atrophy after HT(x) was quite similar to that of whole hearts. Gonadectomy did not have any significant effect on the decreases in whole HW, LV, and RV weights, with similar results in male and female rats. Our results show that the development of unloading-induced cardiac atrophy is substantially reduced in female rats when compared to male rats. Since gonadectomy did not alter the course of cardiac atrophy after HTx, similarly in both male and female rats, we conclude that sex-linked differences in the development of unloading-induced cardiac atrophy are not caused by the activity of sex hormones.

The Longest Living Patient Supported With Left Ventricular Assist Device (14 Years)

Left ventricular assist devices (LVADs) improve survival and reduce symptoms in patients with advanced heart failure; however, the longer-term durability of LVADs remains uncertain especially with older-generation devices. In this case report, we describe the clinical course of a patient who has been successfully treated with the same HeartMate II LVAD for 14 years, the longest published and still ongoing LVAD support with the same originally implanted device.

End-stage heart failure: The future of heart transplant and artificial heart

In the last decades, outcomes significantly improved for both heart transplantation and LVAD. Heart transplantation remains the gold standard for the treatment of end stage heart failure and will remain for many years to come. The most relevant limitations are the lack of grafts and the effects of long-term immunosuppressive therapy that involve infectious, cancerous and metabolic complications despite advances in immunosuppression management. Mechanical circulatory support has an irreplaceable role in the treatment of end-staged heart failure, as bridge to transplant or as definitive implantation in non-transplant candidates. Although clinical results do not overcome those of HTx, improvement in the new generation of devices may help to reach the equipoise between the two therapies. This review will go through the evolution, current status and perspectives of both therapeutics.

The safety of sodium glucose transporter 2 inhibitors and trends in clinical and hemodynamic parameters in patients with left ventricular assist devices

BACKGROUND

The safety and impact of sodium glucose transporter 2 inhibitors (SGLT2-I) in patients with left ventricular assist devices (LVAD) are unknown.

METHODS

A retrospective analysis of all consecutive patients who underwent LVAD Heart Mate 3 (HM3) implantation at a single medical center and received SGLT2-I therapy following surgery was conducted. LVAD parameters, medical therapy, laboratory tests, echocardiography, and right heart catheterization (RHC) study results were recorded and compared before and after initiation of SGLT2-I.

RESULTS

SGLT2-I medications were initiated in 29 (21%) of 138 patients following HM3 implantation (23 (79%) received Empagliflozin and 6 (21%) Dapagliflozin). The mean age at the time of LVAD implantation was 62 ± 6.7 years, 25 (86%) were male, and 23 (79%) had diabetes mellitus. The median time from HM3 implantation to SGLT2-I initiation was 108 days, IQR (26-477). Following SGLT2-I therapy, the daily dose of furosemide decreased from 47 to 23.5 mg/day (mean difference = 23.5 mg/d, 95% CI 8.2-38.7, p = 0.004) and significant weight reduction was observed (mean difference 2.5 kg, 95% CI 0.7-4.3, p = 0.008). Moreover, a significant 5.6 mm Hg reduction in systolic pulmonary artery pressure (sPAP) was measured during RHC (95% CI 0.23-11, p = 0.042) in a subgroup of 11 (38%) patients. LVAD parameters were similar before and after SGLT2-I initiation (p > 0.2 for all). No adverse events were recorded during median follow-up of 354 days, IQR (206-786).

CONCLUSION

SGLT2-I treatment is safe in LVAD patients and might contribute to reduction in patients sPAP.

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.

Fully magnetically centrifugal left ventricular assist device and long-term outcomes: the ELEVATE registry

BACKGROUND AND AIMS

HeartMate 3 (HM3) is a fully magnetically levitated continuous flow left ventricular assist device, which received CE marking in 2015. The ELEVATE Registry was initiated to collect real-world outcomes in patients treated with HM3 post-CE Mark approval.

METHODS

A total of 540 subjects implanted at 26 centres between March 2015 and February 2017 were included in this registry. Of these, 463 received the device as a primary implant (primary implant cohort, PIC), 19 as a pump exchange (pump exchange cohort), and in 58 patients, only anonymized survival data were collected (anonymized cohort, AC). Patients in the PIC contributed to the baseline demographics, survival, adverse events, quality of life (QoL) (EuroQoL-5 Dimensions-5 Levels visual analogue scale), and functional capacity (6 min walk distance) assessments, while patients in the AC contributed only to survival.

RESULTS

Primary implant cohort patients had a mean age of 56 years and were predominantly male (89%) with 48% ischaemic aetiology. The majority of subjects was designated bridge to transplant (66%) and had INTERMACS Profiles 1-3 (70%). At baseline, the subjects had poor functional capacity (104 ± 140 m) and impaired QoL (35 ± 19 points). The overall survival rate of the PIC was 63.3% and survival free of stroke was 58.1% at 5 years. Significant improvements in functional capacity and QoL were observed and maintained for 5 years (301 ± 131 m and 64 ± 20 points, respectively).

CONCLUSIONS

Real-world data from the ELEVATE registry demonstrate an overall survival rate for primary implants of 63.3%. In the PIC, reductions in adverse events for patients in the extended follow-up and improved QoL and functional capacity were observed at 5 years in this patient population with advanced heart failure.

The Role of Artificial Intelligence and Machine Learning in the Prediction of Right Heart Failure after Left Ventricular Assist Device Implantation: A Comprehensive Review

One of the most challenging and prevalent side effects of LVAD implantation is that of right heart failure (RHF) that may develop afterwards. The purpose of this study is to review and highlight recent advances in the uses of AI in evaluating RHF after LVAD implantation. The available literature was scanned using certain key words (artificial intelligence, machine learning, left ventricular assist device, prediction of right heart failure after LVAD) was scanned within Pubmed, Web of Science, and Google Scholar databases. Conventional risk scoring systems were also summarized, with their pros and cons being included in the results section of this study in order to provide a useful contrast with AI-based models. There are certain interesting and innovative ML approaches towards RHF prediction among the studies reviewed as well as more straightforward approaches that identified certain important predictive clinical parameters. Despite their accomplishments, the resulting AUC scores were far from ideal for these methods to be considered fully sufficient. The reasons for this include the low number of studies, standardized data availability, and lack of prospective studies. Another topic briefly discussed in this study is that relating to the ethical and legal considerations of using AI-based systems in healthcare. In the end, we believe that it would be beneficial for clinicians to not ignore these developments despite the current research indicating more time is needed for AI-based prediction models to achieve a better performance.

HeartMate 3 Snoopy: Noninvasive cardiovascular diagnosis of patients with fully magnetically levitated blood pumps during echocardiographic speed ramp tests and Valsalva maneuvers

PURPOSE

The HeartMate 3 (HM3) left ventricular assist device (LVAD) has demonstrated excellent clinical outcomes; however, pump speed optimization is challenging with the available HM3 monitoring. Therefore, this study reports on clinical HM3 parameters collected with a noninvasive HM3 monitoring system (HM3 Snoopy) during echocardiographic speed ramp tests and Valsalva maneuvers.

METHODS

In this prospective, single-center study, the HM3 data communication between the controller and pump was recorded with a novel data acquisition system. Twelve pump parameters sampled every second (1 Hz) and clinical assessments (echocardiography, electrocardiogram (ECG), and blood pressure measurement) during speed ramp tests were analyzed using Pearson's correlation (r, median [IQR]). The cause for the occurrence of pulsatility index (PI)-events during ramp speed tests and valsalva maneuvers was investigated.

RESULTS

In 24 patients (age: 58.9 ± 8.8 years, body mass index: 28.1 ± 5.1 kg/m2, female: 20.8%), 35 speed ramp tests were performed with speed changes in the range of ±1000 rpm from a baseline speed of 5443 ± 244 rpm. Eight HM3 pump parameters from estimated flow, motor current, and LVAD speed together with blood pressure showed positive collinearities (r = 0.9 [0.1]). Negative collinearities were observed for pump flow pulsatility, pulsatility index, rotor noise, and left ventricular diameters (r = -0.8 [0.1]), whereas rotor displacement and heartrate showed absence of collinearities (r = -0.1 [0.08]).

CONCLUSIONS

In this study, the HM3 Snoopy was successfully used to acquire more parameters from the HM3 at a higher sampling rate. Analysis of HM3 per-second data provide additional clinical diagnostic information on heart-pump interactions and cause of PI-events.

IgM marks persistent IgG anti-human leukocyte antigen antibodies in highly sensitized heart transplant patients

BACKGROUND

Sensitization to human leukocyte antigens (HLA) is a persistent problem in heart transplant (HT) candidates. We sought to characterize the anti-HLA antibody and circulating B cell repertoire in a cohort of highly sensitized HT candidates.

METHODS

We assessed immunoglobulin G (IgG) and immunoglobulin M (IgM) anti-HLA antibodies using Luminex single antigen bead assays in a cohort of 11 highly sensitized (HS; calculated panel reactive antibody ≥ 90%) and 3 mildly sensitized (MS) candidates. We also performed B cell receptor repertoire sequencing (BCRseq) in HS candidates and 33 non-candidate controls. HLA antibody strength was measured by mean fluorescence intensity (MFI).

RESULTS

We found that IgM anti-HLA antibodies were present in all HS candidates, but with a lower breadth and strength as compared to IgG. When anti-HLA IgG specificities intersected with IgM, binding strength was higher. In contrast, there were IgM but no intersecting IgG specificities for the MS group. In four candidates in the HS group, IgG anti-HLA antibodies decreased in both breadth and strength after HT, but the decrease in strength was smaller if the IgG possessed a specificity that intersected with pre-transplant IgM. BCRseq revealed larger B cell clonotypes in HS candidates but similar diversity as compared to controls.

CONCLUSIONS

IgM marks IgG anti-HLA antibodies with higher strength before HT and persistence after HT. The presence of IgM intersecting IgG for an anti-HLA specificity may be a useful approach to determine which donor HLA should be avoided for a sensitized candidate.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights From 2023

This special article is the 16th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series, namely the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology. The major themes selected for 2023 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2023 begin with an update on perioperative rehabilitation in cardiothoracic surgery, with a focus on novel methods to best assess patients in the preoperative and postoperative periods, and the impact of rehabilitation on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into inhaled pulmonary vasodilators, coronary revascularization surgery, and discussion of causes of coronary graft failure after surgery. The third theme is focused on cardiothoracic transplantation, with discussions focusing on bridge-to-transplantation strategies. The fourth theme is focused on mechanical circulatory support, with discussions focusing on both temporary and durable support. The fifth and final theme is an update on medical cardiology, with a focus on outcomes of invasive approaches to heart disease. The themes selected for this article are only a few of the diverse advances in the specialty during 2023. These highlights will inform the reader of key updates on various topics, leading to improved perioperative outcomes for patients with cardiothoracic and vascular disease.

Value of Invasive Hemodynamic Assessments in Patients Supported by Continuous-Flow Left Ventricular Assist Devices

Left ventricular assist devices (LVADs) are increasingly used in patients with end-stage heart failure (HF). There is a significant risk of HF admissions and hemocompatibility-related adverse events that can be minimized by optimizing the LVAD support. Invasive hemodynamic assessment, which is currently underutilized, allows personalization of care for patients with LVAD, and may decrease the need for recurrent hospitalizations. It also aids in triaging patients with persistent low-flow alarms, evaluating reversal of pulmonary vasculature remodeling, and assessing right ventricular function. In addition, it can assist in determining the precipitant for residual HF symptoms and physical limitation during exercise and is the cornerstone of the assessment of myocardial recovery. This review provides a comprehensive approach to the use of invasive hemodynamic assessments in patients supported with LVADs.

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.

Major adverse kidney events predict reduced survival in ventricular assist device supported patients

AIMS

There is limited data describing major adverse kidney events (MAKE) in patients supported with ventricular assist devices (VAD). We aim to describe the association between MAKE and survival, risk factors for MAKE, and renal trajectory in VAD supported patients.

METHODS AND RESULTS

We conducted a single-centre retrospective analysis of consecutive VAD implants between 2010 and 2019. Baseline demographics, biochemistry, and adverse events were collected for the duration of VAD support. MAKE was defined as the first event to occur of sustained drop (>50%) in estimated glomerular filtration rate (eGFR), progression to stage V chronic kidney disease, initiation or continuation of renal replacement therapy beyond implant admission or death on renal replacement therapy at any time. One-hundred and seventy-three patients were included, median age 56.8 years, 18.5% female, INTERMACS profile 1 or 2 in 75.1%. Thirty-seven patients experienced MAKE. On multivariate analysis, post-implant clinical right ventricular failure and the presence of chronic haemolysis, defined by the presence of schistocytes on blood film analysis, were significantly associated with increased risk of MAKE (adjusted odds ratio 9.88, P < 0.001 and adjusted odds ratio 3.33, P = 0.006, respectively). MAKE was associated with reduced survival (hazard ratio 4.80, P < 0.001). Patients who died or experienced MAKE did not demonstrate the expected transient 3-month improvement in eGFR, seen in other cohorts.

CONCLUSIONS

MAKE significantly impacts survival. In our cohort, MAKE was predicted by post-implant right ventricular failure and chronic haemolysis. The lack of early eGFR improvement on VAD support may indicate higher risk for MAKE.

Durable Mechanical Circulatory Support: JACC Scientific Statement

Despite advances in medical therapy for patients with stage C heart failure (HF), survival for patients with advanced HF is <20% at 5 years. Durable left ventricular assist device (dLVAD) support is an important treatment option for patients with advanced HF. Innovations in dLVAD technology have reduced the risk of several adverse events, including pump thrombosis, stroke, and bleeding. Average patient survival is now similar to that of heart transplantation at 2 years, with 5-year dLVAD survival now approaching 60%. Unfortunately, greater adoption of dLVAD therapy has not been realized due to delayed referral of patients to advanced HF centers, insufficient clinician knowledge of contemporary dLVAD outcomes (including gains in quality of life), and deprioritization of patients with dLVAD support waiting for heart transplantation. Despite these challenges, novel devices are on the horizon of clinical investigation, offering smaller size, permitting less invasive surgical implantation, and eliminating the percutaneous lead for power supply.

Transdermal wires for improved integration in vivo

Alternative engineering approaches have led the design of implants with controlled physical features to minimize adverse effects in biological tissues. Similar efforts have focused on optimizing the design features of percutaneous VAD drivelines with the aim to prevent infection, omitting however a thorough look on the implant-skin interactions that govern local tissue reactions. Here, we utilized an integrated approach for the biophysical modification of transdermal implants and their evaluation by chronic sheep implantation in comparison to the standard of care VAD drivelines. We developed a novel method for the transfer of breath topographical features on thin wires with modular size. We examined the impact of implant's diameter, surface topography, and chemistry on macroscopic, histological, and physical markers of inflammation, fibrosis, and mechanical adhesion. All implants demonstrated infection-free performance. The fibrotic response was enhanced by the increasing diameter of implants but not influenced by their surface properties. The implants of small diameter promoted mild inflammatory responses with improved mechanical adhesion and restricted epidermal downgrowth, in both silicone and polyurethane coated transdermal wires. On the contrary, the VAD drivelines with larger diameter triggered severe inflammatory reactions with frequent epidermal downgrowth. We validated these effects by quantifying the infiltration of macrophages and the level of vascularization in the fibrotic zone, highlighting the critical role of size reduction for the benign integration of transdermal implants with skin. This insight on how the biophysical properties of implants impact local tissue reactions could enable new solutions on the transdermal transmission of power, signal, and mass in a broad range of medical devices.

Exercise Performance and Quality of Life of Left Ventricular Assist Device Patients After Long-Term Outpatient Cardiac Rehabilitation

PURPOSE

Exercise performance and quality of life (QoL) of left ventricular assist device (LVAD) patients improve after early cardiac rehabilitation (CR). The purpose of this study was to examine the efficacy of multiprofessional long term phase 3 outpatient CR, and whether cardiopulmonary exercise testing (CPX) and 6-min walk testing (6MWT) post-LVAD implantation predict hospital readmission.

METHODS

This retrospective observational cohort study included 29 LVAD patients (58.6 ± 7.7 yr, female: 13.8%, body mass index: 29.4 ± 3.3 kg/m 2 ). Functional performance tests (CPX, 6MWT, sit-to-stand test), QoL, and psychological surveys (Kansas City Cardiomyopathy Questionnaire, hospital anxiety and depression scale, and Control Convictions about Disease and Health [KKG]) were performed at baseline and at the end of CR.

RESULTS

The CR was initiated at a median (IQR) of 159 (130-260) d after LVAD implantation for a duration of 340 (180-363) d with 46.8 ± 23.2 trainings. The 6MWT (408.4 ± 113.3 vs 455.4 ± 115.5 m, P = .003) and sit-to-stand test (16.7 ± 6.9 vs 19.0 ± 5.3 repetitions, P = .033) improved, but relative peak oxygen uptake (V˙ o2peak : 9.4 [8.2-14.4] vs 9.3 [7.8-13.4] mL/min/kg, P = .57) did not change. Using receiver operating characteristic curve analysis, baseline V˙ o2peak values were associated with readmission 1-yr after CR onset (C-statistic = 0.88) with a cutoff value of V˙ o2peak < 9.15 mL/min/kg (100% sensitivity, 78% specificity, P < .001). The Kansas City Cardiomyopathy Questionnaire self-efficacy and knowledge (+6.3 points), QoL (+5.0 points), and social limitation (+7.1 points) demonstrated clinically important changes. In addition, the hospital anxiety and depression scale showed a significant reduction in anxiety (4.6 ± 3.2 vs 2.6 ± 2.4, P = .03).

CONCLUSIONS

Long-term CR is safe and LVAD outpatients showed improvement of QoL, anxiety, and submaximal exercise performance. In addition, V˙ o2peak and 6MWT have prognostic value for readmission.

The Relation Between Viscous Energy Dissipation and Pulsation for Aortic Hemodynamics Driven by a Left Ventricular Assist Device

Left ventricular assist device (LVAD) provides mechanical circulatory support for patients with advanced heart failure. Treatment using LVAD is commonly associated with complications such as stroke and gastro-intestinal bleeding. These complications are intimately related to the state of hemodynamics in the aorta, driven by a jet flow from the LVAD outflow graft that impinges into the aorta wall. Here we conduct a systematic analyses of hemodynamics driven by an LVAD with a specific focus on viscous energy transport and dissipation. We conduct a complementary set of analysis using idealized cylindrical tubes with diameter equivalent to common carotid artery and aorta, and a patient-specific model of 27 different LVAD configurations. Results from our analysis demonstrate how energy dissipation is governed by key parameters such as frequency and pulsation, wall elasticity, and LVAD outflow graft surgical anastomosis. We find that frequency, pulsation, and surgical angles have a dominant effect, while wall elasticity has a weaker effect, in determining the state of energy dissipation. For the patient-specific scenario, we also find that energy dissipation is higher in the aortic arch and lower in the abdominal aorta, when compared to the baseline flow without an LVAD. This further illustrates the key hemodynamic role played by the LVAD outflow jet impingement, and subsequent aortic hemodynamics during LVAD operation.

Timing and Outcomes of Concurrent and Sequential Biventricular Assist Device Implantation: A Society of Thoracic Surgeons Intermacs Analysis

BACKGROUND

Biventricular heart failure remains a clinically challenging condition to manage. Available literature describing the use of durable biventricular assist device (BiVAD) support has numerous limitations hindering the development of useful treatment algorithms. Analysis of BiVAD use within a large multicenter data set is needed to clarify outcomes associated with this therapy.

METHODS

The Society of Thoracic Surgeons Intermacs database was queried to identify adults aged ≥18 years who received durable circulatory support from January 1, 2010, to December 31, 2220. The data set was divided into the following cohorts: (1) left ventricular assist device (LVAD) only (n = 27,325), (2) LVAD and concurrent right ventricular assist device (RVAD) (n = 1090), and (3) LVAD and sequential RVAD (n = 556). Propensity score matching was used to compare 1-year mortality and adverse events between concurrent (n = 565) and sequential BiVADs (n = 565).

RESULTS

Overall survival within 1 year was significantly worse for the BiVAD cohort compared with the LVAD-only cohort (12-month survival: 50.8% vs 82.6%; log-rank P < .001). In a propensity-matched cohort, patients implanted with a BiVAD concurrently had an improved survival compared with those implanted an LVAD and an RVAD sequentially (12-month survival: 55.8% vs 41.8%; log-rank P < .001). Early (<3 months) adverse event rates were higher among patients receiving sequential BiVADs for bleeding, infection, neurologic dysfunction, and renal dysfunction (P < .01).

CONCLUSIONS

After matching for patient and disease characteristics, patients with sequential BiVAD implantation have worse outcomes than patients with concurrent BiVAD implantation.

Left ventricular assist device exchange: a review of indications, operative procedure, and outcomes

The use of left ventricular assist devices (LVADs) is intended to treat patients with end-stage heart failure. Owing to technological advances, these devices are becoming more durable. However, LVADs may need to be exchanged when complications arise and heart transplantation is not possible. Indications for LVAD exchange (LVADE) include device thrombosis, device infections, and pump component failure. LVADE has historically been associated with a high risk of morbidity and mortality. In this review, we discuss the indications of LVADE, the decisional and technical aspects during surgery, and outcomes.

Managing valvular pathology during LVAD implantation

Since the time of their invention, implantable continuous flow left ventricular assist devices (LVADs) have improved the quality of life and extended survival for patients with advanced heart failure. The decision surgeons and their physician colleagues make with these patients to undergo implantation must come with full understanding of the immediate, short-term, and long-term implications of such a life-changing procedure. The presence of pathology regarding the aortic, mitral, and tricuspid valves introduces particularly complex problems for the surgical treatment strategy. Concomitant valve repair or replacement increases cardiopulmonary bypass and cross clamp times, and could potentially lead to worse outcomes in the perioperative setting. Following perioperative recovery, valvular pathology may worsen or arise de novo given the often drastic immediate physiologic changes in blood flow, septal function, and, over time, ventricular remodeling. Over the past two decades, there has been vast improvement in the device manufacturing, surgical techniques, and medical management surrounding LVAD implantation. Yet, addressing concomitant valvular pathology remains a complex question with no perfect solutions. This review aims to briefly describe the evolution of approach to valvular pathology in the LVAD patient and offer our opinion and treatment rationale.

Left ventricular functional improvement appears to contribute to lower rates of device thrombosis in patients on durable mechanical circulatory support

By unloading the failing heart, left ventricular (LV) assist devices (LVADs) provide a favorable environment for reversing adverse structural and functional cardiac changes. Prior reports have suggested that an improved native LV function might contribute to the development of LVAD thrombosis. We used the Interagency Registry for Mechanically Assisted Circulatory Support and found that LV functional improvement is associated with a lower risk for device thrombosis. The risk for cerebrovascular accident and transient ischemic attack was comparable across post-LVAD LV function subgroups, while the risk of hemolysis was lower in subgroups of patients with better LV function on LVAD support.

Infections in Patients With Left Ventricular Assist Devices: Current State and Future Perspectives

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment.

Gastrointestinal Bleeding in Patients Supported with Left Ventricular Assist Devices: The Journey from Bridging to Destination

End-stage heart failure is a prevalent and fatal cardiovascular disease. Almost 1 in 4 cases of mortality in the United States is attributed to heart failure. Left ventricular assist devices (LVADs) have emerged as a safe destination therapy or bridge to transplant. Despite remarkable results, LVAD is associated with significant adverse events, such as gastrointestinal bleeding (GIB). In this review, we aimed to understand the incidence and prevalence, pathophysiologic mechanisms, predictors, diagnostic mechanisms, management, and preventative measures of GIB in patients with an LVAD. GIB is a common adverse event in patients with an LVAD with an incidence of 15% to 25%. The exact pathogenesis of GIB is poorly understood. However, different mechanisms of bleeding have been described, such as arteriovenous malformations, acquired von Willebrand syndrome, coagulopathy, and treatment with antithrombotic therapy. Upper GIB is the most common site of GIB in patients with an LVAD. The management of GIB in patients with LVAD includes ensuring hemodynamic stability, holding or reversing antithrombotic therapy, and investigating and controlling the source of GIB through diagnostic and interventional endoscopic and radiologic means. Prophylactic medication use (e.g., danazol, octreotide, and bevacizumab) can decrease the risk of GIB in patients with an LVAD by decreasing arteriovenous malformations. Despite that the overall risk of GIB has decreased with new advancements in LVAD technology, further studies are needed regarding predictors, risk stratification, and optimal antithrombotic therapy to minimize the morbidity and mortality in patients with an LVAD. In conclusion, prompt diagnosis and management in a multidisciplinary team approach are crucial and lifesaving in such a life-threatening condition.

Pilot test of a multicomponent implementation strategy for equity in advanced heart failure allocation

Advanced heart failure (AHF) therapy allocation is vulnerable to bias related to subjective assessments and poor group dynamics. Our objective was to determine whether an implementation strategy for AHF team members could feasibly contribute to organizational and culture change supporting equity in AHF allocation. Using a pretest-posttest design, the strategy included an 8-week multicomponent training on bias reduction, standardized numerical social assessments, and enhanced group dynamics at an AHF center. Evaluations of organizational and cultural changes included pretest-posttest AHF team member surveys, transcripts of AHF meetings to assess group dynamics using a standardized scoring system, and posttest interviews guided by a framework for implementing a complex strategy. Results were analyzed with qualitative descriptive methods and Brunner-Munzel tests for relative effect (RE, RE >0.5 signals posttest improvement). The majority of survey metrics revealed potential benefit with RE >0.5. REs were >0.5 for 5 of 6 group dynamics metrics. Themes for implementation included (1) promoting equitable distribution of scarce resources, (2) requiring a change in team members' time investment to correct bias and change the meeting structure, (3) slowing and then accelerating the allocation process, and (4) adaptable beyond AHF and reinforceable with semi-annual trainings. An implementation strategy for AHF equity demonstrated the feasibility for organizational and culture changes.

Quality of Anticoagulation With Phenprocoumon and Warfarin in Left Ventricular Assist Device Patients: A Multicenter Study

VISUAL ABSTRACT

of key results. INR, international normalized ratio; TTR, time in therapeutic range; PTR, percentage of tests in range; HRAE, hemocompatibility-related adverse event; FFUV, first follow-up visit; GIB, gastrointestinal bleeding; HR, hazard ratio.http://links.lww.com/ASAIO/A961.

Rescuing the right ventricle: A conceptual framework to target new interventions for patients receiving a durable left ventricular assist device

Despite significant advances in durable LVAD technology, right heart failure remains a morbid and fatal condition that is difficult to predict, prevent, and successfully treat.

Heart transplantation in the era of corona virus disease 2019: Impact of the pandemic on donors, recipients and outcome

INTRODUCTION

Since March 2020, the COVID-19 pandemic has tremendously impacted health care all around the globe. We analyzed the impact of the pandemic on donors, recipients, and outcome of heart transplantation (HTx).

METHODS

Between 2010 and early 2022, a total of n = 235 patients underwent HTx in our department. Patients were assigned to the study groups regarding the date of the performed HTx. Group 1 (09/2010 to 02/2020): n = 160, Group 2 (03/2020 to 02/2022): n = 75.

RESULTS

Since the pandemic, the etiology of heart failure in the recipients has shifted from dilated (Group 1: 53.8%, Group 2: 32.0%) to ischemic cardiomyopathy (Group 1: 39.4%, Group 2: 50.7%, p < .01). The percentage of high urgency status of the recipients dropped from 50.0% to 36.0% (p = .05), and the use of left ventricular assist (LVAD) support from 56.9% to just 37.3% (p < .01). Meanwhile, the waiting time for the recipients also decreased by about 40% (p = .05). Since the pandemic, donors were 2- times more likely to have been previously resuscitated (Group 1: 21.3%, Group 2: 45.3% (p < .01), and drug abuse increased by more than 3-times (p < .01), indicating acceptance of more marginal donors. Surprisingly, the incidence of postoperative severe primary graft dysfunction requiring extracorporeal life support decreased from 33.1% to 19.4% (p = .04) since the pandemic.

CONCLUSION

The COVID-19 pandemic affected both donors and recipients of HTX but not the postoperative outcome. Donors nowadays are more likely to suffer from ischemic heart disease and are less likely to be on the high-urgency waitlist and on LVAD support. Simultaneously, an increasing number of marginal donors are accepted, leading to shorter waiting times.

Association of Days Alive and Out of the Hospital After Ventricular Assist Device Implantation With Adverse Events and Quality of Life

Importance

There is a need to better assess the cumulative effect on morbidity and mortality in patients undergoing durable left ventricular assist device (LVAD) implantation. This study evaluates a patient-centered performance metric (days alive and out of hospital [DAOH]) for durable LVAD therapy.

Objective

To determine the incidence of percent of DAOH before and after LVAD implantation and (2) explore its association with established quality metrics (death, adverse events [AEs], quality of life).

Design, Settings, and Participants

This was a retrospective national cohort study of Medicare beneficiaries implanted with a durable continuous-flow LVAD between April 2012 and December 2016. The data were analyzed from December 2021 to May 2022. Follow-up was 100% complete at 1 year. Data from The Society of Thoracic Surgeons Intermacs registry were linked to Medicare claims.

Main Outcomes and Measures

The number of DAOH 180 days before and 365 days after LVAD implantation and daily patient location (home, index hospital, nonindex hospital, skilled nursing facility, rehabilitation center, hospice) were calculated. Percent of DAOH was indexed to each beneficiary's pre- (percent DAOH-BF) and postimplantation (percentage of DAOH-AF) follow-up time. The cohort was stratified by terciles of percentage of DAOH-AF.

Results

Among the 3387 patients included (median [IQR] age: 66.3 [57.9-70.9] years), 80.9% were male, 33.6% and 37.1% were Interfaces Patient Profile 2 and 3, respectively, and 61.1% received implants as destination therapy. Median (IQR) percent of DAOH-BF was 88.8% (82.7%-93.8%) and 84.6% (62.1-91.5%) for percent of DAOH-AF. While DAOH-BF was not associated with post-LVAD outcomes, patients in the low tercile of percentage of DAOH-AF had a longer index hospitalization stay (mean, 44 days; 95% CI, 16-77), were less likely to be discharged home (mean. -46.4 days; 95% CI, 44.2-49.1), and spent more time in a skilled nursing facility (mean, 27 days; 95% CI, 24-29), rehabilitation center (mean, 10 days; 95% CI, 8-12), or hospice (mean, 6 days; 95% CI, 4-8). Increasing percentage of DAOH-AF was associated with patient risk, AEs, and indices of HRQoL. Patients experiencing non-LVAD-related AEs had the lowest percentage of DAOH-AF.

Conclusions and Relevance

Significant variability existed in the percentage of DAOH within a 1-year time horizon and was associated with the cumulative AEs burden. This patient-centered measure may assist clinicians in informing patients about expectations after durable LVAD implantation. Validation of percentage DAOH as a quality metric for LVAD therapy across centers should be explored.

Group Dynamics and Allocation of Advanced Heart Failure Therapies-Heart Transplants and Ventricular Assist Devices-By Gender, Racial, and Ethnic Group

Background US regulatory framework for advanced heart failure therapies (AHFT), ventricular assist devices, and heart transplants, delegate eligibility decisions to multidisciplinary groups at the center level. The subjective nature of decision-making is at risk for racial, ethnic, and gender bias. We sought to determine how group dynamics impact allocation decision-making by patient gender, racial, and ethnic group. Methods and Results We performed a mixed-methods study among 4 AHFT centers. For ≈ 1 month, AHFT meetings were audio recorded. Meeting transcripts were evaluated for group function scores using de Groot Critically Reflective Diagnoses protocol (metrics: challenging groupthink, critical opinion sharing, openness to mistakes, asking/giving feedback, and experimentation; scoring: 1 to 4 [high to low quality]). The relationship between summed group function scores and AHFT allocation was assessed via hierarchical logistic regression with patients nested within meetings nested within centers, and interaction effects of group function score with gender and race, adjusting for patient age and comorbidities. Among 87 patients (24% women, 66% White race) evaluated for AHFT, 57% of women, 38% of men, 44% of White race, and 40% of patients of color were allocated to AHFT. The interaction between group function score and allocation by patient gender was statistically significant (P=0.035); as group function scores improved, the probability of AHFT allocation increased for women and decreased for men, a pattern that was similar irrespective of racial and ethnic groups. Conclusions Women evaluated for AHFT were more likely to receive AHFT when group decision-making processes were of higher quality. Further investigation is needed to promote routine high-quality group decision-making and reduce known disparities in AHFT allocation.

The Impact of MOMENTUM 3 Trial Eligibility on Left Ventricular Assist Device Outcomes: A Real-World Experience

INTRODUCTION

Although the landmark MOMENTUM 3 trial was associated with excellent short-term left ventricular assist device (LVAD) outcomes, many end-stage heart failure patients would not have met the trial eligibility criteria. Moreover, the outcomes of trial ineligible patients are poorly characterized. Therefore, we undertook this study to compare MOMENTUM 3 eligible and ineligible patients.

METHODS

We conducted a retrospective review of all primary LVAD implants from 2017 to 2022. Primary stratification was according to MOMENTUM 3 inclusion and exclusion criteria. Primary outcome was survival. Secondary outcomes included complications and length of stay. Multivariable Cox proportional hazards regression models were constructed to further characterize outcomes.

RESULTS

From 2017 to 2022, 96 patients underwent primary LVAD implantation. Thirty-seven (38.54%) patients were trial eligible while 59 (61.46%) were ineligible. When stratified by trial eligibility, patients who were trial eligible had higher 1-year (80.15% versus 94.52%, P = 0.04) and 2-year survival (70.17% versus 94.52%, P = 0.02). Multivariable analysis showed that trial eligibility was protective of mortality at both 1 y (HR: 0.19 [0.04-0.99], P = 0.049) and 2 y (HR: 0.17 [0.03-0.81], P = 0.03). Although the groups had similar rates of bleeding, stroke, and right ventricular failure, trial ineligibility was associated with a longer periprocedural length of stay.

CONCLUSIONS

In conclusion, the majority of contemporary LVAD patients would not have been eligible for the MOMENTUM 3 trial. Ineligible patients have decreased but acceptable short-term survival. Our findings suggest that a simply reductionist approach to short-term mortality may improve outcomes but fail to capture the majority of patients who could benefit from therapy.

Impact of ABO Blood Group on Thromboembolic and Bleeding Complications in Patients with Left Ventricular Assist Devices

BACKGROUND

 The ABO blood group system is linked to hemostasis via its relationship with von Willebrand factor (VWF) and factor VIII (FVIII). In the current study, we investigated the association of the ABO system with clinical outcomes as well as VWF and platelet function in patients with left ventricular assist devices (LVADs).

METHODS

 Bleeding and thromboembolic complications were assessed in 111 patients during 1 year after LVAD implantation. In 67 LVAD patients, VWF antigen, VWF activity, VWF ristocetin cofactor, VWF collagen-binding, and FVIII activity were assessed. Platelet surface P-selectin and activated glycoprotein IIb/IIIa were determined by flow cytometry, and soluble P-selectin was measured with an enzyme-linked immunoassay. Platelet aggregation was assessed by light transmission and impedance aggregometry.

RESULTS

 Thirty-six patients (32.4%) experienced a bleeding and 22 patients (19.8%) a thromboembolic event. In univariate analyses, patients with blood group O had numerically more bleeding complications and less thromboembolic events as compared to patients with blood group non-O (both p ≥ 0.05). After multivariable adjustment, blood group O was significantly associated with a higher risk of bleeding (hazard ratio 2.42 [95% confidence interval 1.03-5.70], p = 0.044) but not linked to thromboembolic complications.

CONCLUSION

 Patients with blood group O had significantly lower levels of VWF and FVIII (all p < 0.05), whereas P-selectin expression in response to thrombin-receptor activating peptide and soluble P-selectin were higher as compared to patients with blood group non-O (both p < 0.05). LVAD patients with blood group O are at an increased bleeding risk, potentially due to lower VWF and FVIII levels.

Novel Estimates of Renal Function are Associated with Short-Term Left Ventricular Assist Device Outcomes

INTRODUCTION

Although preoperative kidney function has been associated with left ventricular assist device (LVAD) outcomes, most previous estimates of glomerular filtration rates (eGFRs) have utilized race in the calculation. Recently, novel eGFR equations independent of race have been suggested and validated. Therefore, we undertook this study to evaluate the predictive value of a novel, non-race-based eGFR calculation on short-term LVAD outcomes.

METHODS

We conducted a retrospective review of all primary LVAD implants from 2017 to 2022 at our institution. eGFR was calculated using the novel Chronic Kidney Disease Epidemiology Collaboration 2021 formula (CKD-EPI 2021). eGFR was also calculated according to the Modification of Diet in Renal Disease equation for historical reference. Primary stratification was by eGFR: ≥60, 30-60, and <30. The primary outcome was 1-y survival. Multivariable Cox proportional hazards regression modeling was used to further evaluate the impact of kidney function on 1-y mortality.

RESULTS

From 2017 to 2022, 91 patients underwent LVAD implantation with a HeartMate 3 device. The average age was 65.20 ± 11.08, 77 (84.62%) were male, and 14 (15.38%) were Black. The mean CKD-EPI 2021 eGFR was 56.07 ± 23.55 compared with 54.72 ± 26.37 as calculated by Modification of Diet in Renal Disease (P = 0.719). Overall, 30-d and 1-y survival was 96.7% and 85.0%, respectively. When stratified by eGFR, there was a significant difference in 1-y survival (≥60, 93.46%; 30-60, 87.36%; <30, 62.75%; P = 0.016). On multivariable analysis, a preoperative eGFR <30 was associated with an increased hazard of 1-y mortality (5.58 [1.06-29.17], P = 0.043).

CONCLUSIONS

In conclusion, non-race-based estimates of renal function are predictive of short-term LVAD outcomes. Further investigation of this phenomenon is warranted.

Elderly Patients With Higher Acuity Have Similar Left Ventricular Assist Device Outcomes as Younger Patients at a Nontransplant Center

Although left ventricular assist device (LVAD) implantation is associated with acceptable survival, previous reports have demonstrated that advanced age is associated with increased short-term mortality. Because age is a relative contraindication to transplantation, nontransplant centers tend to implant a disproportionate number of elderly patients. We undertook this study to evaluate the impact of advanced age on LVAD outcomes at a nontransplant center. We conducted a retrospective review of all LVAD implants at our center from 2017 to 2022. Primary stratification was by age >70 years. The primary outcome was survival as assessed by the Kaplan-Meier method. The risk of 1-year mortality was further evaluated using multivariable Cox proportional hazards regression modeling. From 2017 to 2022, 93 patients underwent LVAD implantation. The mean age was 65.03 ± 11.28 years, with a median age of 68 (60 to 73) years. Most patients were INTERMACS 1 or 2 (71 patients; 76.34%). When stratified by age, 41 patients (44.09%) were aged ≥70 years. Patients aged ≥70 years had similar 30-day (96.15% vs 100.00%, p = 0.213), 1-year (90.05% vs 84.00%, p = 0.444), and 2-year survival (82.03% vs 84.00%, p = 0.870). When only the INTERMACS 1 and 2 patients with higher acuity were included, there was still no difference in 30-day, 1-year, or 2-year survival. On multivariable analysis, age >70 years was not associated with an increased hazard of 1-year mortality (0.90 [0.22 to 3.67], p = 0.878). In conclusion, in carefully selected patients, age >70 years is not associated with increased short-term mortality. Age alone should not be a contraindication to LVAD therapy.

HFSA Expert Consensus Statement on the Medical Management of Patients on Durable Mechanical Circulatory Support

The medical management of patients supported with durable continuous flow left ventricular assist device (LVAD) support encompasses pharmacologic therapies administered in the preoperative, intraoperative, postoperative and chronic LVAD support stages. As patients live longer on LVAD support, the risks of LVAD-related complications and progression of cardiovascular and other diseases increase. Using existing data from cohort studies, registries, randomized trials and expert opinion, this Heart Failure Society of America Consensus Document on the Medical Management of Patients on Durable Mechanical Circulatory Support offers best practices on the management of patients on durable MCS, focusing on pharmacological therapies administered to patients on continuous flow LVADs. While quality data in the LVAD population are few, the utilization of guideline directed heart failure medical therapies (GDMT) and the importance of blood pressure management, right ventricular preload and afterload optimization, and antiplatelet and anticoagulation regimens are discussed. Recommended pharmacologic regimens used to mitigate or treat common complications encountered during LVAD support, including arrhythmias, vasoplegia, mucocutaneous bleeding, and infectious complications are addressed. Finally, this document touches on important potential pharmacological interactions from anti-depressants, herbal and nutritional supplements of relevance to providers of patients on LVAD support.