The Inflammatory Response to Ventricular Assist Devices

Implications of Preoperative C-Reactive Protein Levels in Heart Transplant Patients-A Single-Center Retrospective Study

Background: Heart transplant is the final therapeutic option for end-stage heart failure patients. It has been used with increasing success as a surgical procedure, greatly influenced by advances in diagnostic and prognostic tools. The aim of this paper was to study potential implications of C-reactive protein (CRP) in patients who underwent heart transplants. Methods: Our cohort included 43 adult patients from the Emergency Institute for Cardiovascular Diseases and Transplant of Târgu Mureș who underwent heart transplants in our center between 2011 and 2023. Correlations between CRP levels and different characteristics of the patients were investigated, and the optimal cut-off value for CRP levels in relation to the 6-month mortality rate was determined. The central tendencies of the baseline characteristics of patients who had a CRP value lower than the cut-off and those with a value higher than it were compared using parametric or nonparametric tests. Results: Significant correlations between the preoperative CRP levels and 6-month mortality rate (r = 0.35; 95%CI: 0.05-0.60; p = 0.02), as well as previous cardiac resynchronization therapy (CRT) and preoperative CRP levels (r = -0.37; 95%CI: -0.61--0.07, p = 0.01) were highlighted. A value for CRP > 1.66 mg/dL was found to be associated with 6-month mortality (OR = 18.00; 95%CI: 1.90-170.33, p < 0.01). Moreover, the patients who received CRT before transplantation had significantly lower levels of CRP when compared to those who did not receive CRT (p = 0.01). Conclusions: Preoperative CRP levels could represent a valuable asset in the follow-up algorithm of heart transplant patients. The lower levels of CRP in patients who benefited from CRT before transplantation highlights the importance of understanding the complex mechanisms of inflammation and increasing focus on device therapy for future transplant recipients. Further prospective studies with larger cohorts are needed for validation.

Peri-operative fever and LVAD: SIRS or impaired right ventricular strain?

BACKGROUND

An inflammatory milieu after left ventricular assist device (LVAD) implantation is associated with multi-organ dysfunction and pre-operative heightened inflammatory state is associated with right ventricular failure after LVAD implantation.

METHODS

We performed a retrospective analysis of 30 LVAD patients in our institution within the last 2 years for the development of fever and compared them to 30 non-LVAD open-heart surgery patients.

RESULTS

Our results suggest that patients undergoing LVAD implantation are more likely to develop fever in the immediate post-operative period compared to other open-heart surgeries. This is independent of pharmacological treatment, age, or ethnical background. Females and obese patients were more likely to develop fever.

CONCLUSION

Patients with right ventricular dysfunction, as demonstrated by elevated central venous pressure (CVP), had the strongest correlation with fever development. These results pose the question if there is a systemic inflammatory response-like phenomenon driven by increased right ventricular dysfunction.

Biosensors with left ventricular assist devices

Heart failure imposes a significant global health burden, standing as a primary contributor to mortality. Various indicators and physiological shifts within the body may hint at distinct cardiac conditions. Specific biosensors have the capability to identify these changes. Integrating or embedding these biosensors into mechanical circulatory support devices (MCSDs), such as left ventricular assist devices (LVADs), becomes crucial for monitoring alterations in biochemical and physiological factors subsequent to an MCSD implantation. Detecting abnormal changes early in the course of disease progression will allow for improved patient outcomes and prognosis following an MCSD implantation. The aim of this review is to explore the available biosensors that may be coupled or implanted alongside LVADs to monitor biomarkers and changes in physiological parameters. Different fabrication materials for the biosensors are discussed, including their advantages and disadvantages. This review also examines the feasibility of integrating feedback control mechanisms into LVAD systems using data from the biosensors. Challenges facing this emerging technology and future directions for research and development are outlined as well. The overarching goal is to provide an overview of how implanted biosensors may improve the performance and outcomes of LVADs through continuous monitoring and closed-loop control.

Iron Deficiency in Patients with Left Ventricular Assist Devices

Iron deficiency is a common and independent predictor of adverse outcomes in patients with heart failure. The implications of iron deficiency in patients implanted with a left ventricular assist device (LVAD) are less established. This review recaps data on the prevalence, characteristics and impact of Iron deficiency in the LVAD population. A systematic search yielded eight studies involving 517 LVAD patients, with iron deficiency prevalence ranging from 40% to 82%. IV iron repletion was not associated with adverse events and effectively resolved iron deficiency in most patients. However, the effects of iron deficiency and iron repletion on post-implant survival and exercise capacity remain unknown. Although iron deficiency is highly prevalent in LVAD patients, its true prevalence and adverse effects may be misestimated due to inexact diagnostic criteria. Future randomised controlled trials on IV iron treatment in LVAD patients are warranted to clarify the significance of this common comorbidity.

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

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

Preliminary report of extracorporeal blood purification therapy in patients receiving LVAD: Cytosorb or Jafron HA330

BACKGROUND

Left ventricular assist device (LVAD) candidates are at increased risk of immune dysregulation and infectious complications. To attenuate the elevated proinflammatory cytokine levels and associated adverse clinical outcomes, it has been postulated that extracorporeal blood purification could improve the overall survival rate and morbidity of patients undergoing LVAD implantation.

METHODS

We retrospectively reviewed prospectively collected data of 15 patients who underwent LVAD implantation at our center between January 2021 and March 2022. Of these, 15 (100%) who received HeartMate 3™ (St. Jude Medical, Abbott, MN, USA) device were eligible. Intraoperatively, patients were single randomized 1:1:1 to three groups: group 1, patients who received Cytosorb therapy (n = 5; installed in the CPB circuit); group 2, patients who received Jafron HA330 (n = 5; installed in the CPB circuit); and control group 3, patients who did not receive filter (n = 5; usual care, neither Cytosorb nor Jafron during CPB). Baseline patient characteristics and intraoperative data were compared between the groups. Blood sample analyses were performed to assess the levels of inflammatory markers (IL-1, 6, 8; CRP, Leukocyte, Lactate, PCT, NT-proBNP, TNF-α) in both preoperative and postoperative data.

RESULTS

Baseline patient characteristics were similar in all three groups. We found that IL1α; IL 6; IL8; Lactatedehydrogenase, PCT, pro-BNP, CRP; Leukocyte, and TNFα levels significantly increased with LVAD implantation and that neither Cytosorb nor Jafron influenced this response. In-hospital mortality and overall survival during follow-up were similar among the groups.

CONCLUSION

Our preliminary results showed that hemoadsorption therapy using Cytosorb or Jafron hemoadsorption (HA) 330 may not be clinically beneficial for patients with advanced heart failure undergoing LVAD implantation. Large prospective studies are needed to evaluate the potential role of HA therapy in improving outcomes in patients undergoing LVAD implantation.

Clinical Outcomes of SARS-CoV-2 Infection in Pediatric Patients on Ventricular Assist Device Support: An ACTION Registry Analysis

Adult patients on left ventricular assist device (LVAD) support have increased morbidity and mortality after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. There are no reported clinical data describing outcomes among pediatric patients on ventricular assist device (VAD) support infected with SARS-CoV-2. We conducted a retrospective study using the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry to evaluate patient characteristics and clinical outcomes after SARS-CoV-2 infection. A total of 22 children on VAD support (median age at infection 10.6 years) from 16 centers tested positive for SARS-CoV-2. Cardiomyopathy (59.1%) and congenital heart disease (40.9%) were the most common primary diagnoses. The type of support included LVAD in 19 (86.4%), biventricular assist device (BIVAD) in one (4.5%), and single ventricle VAD in two (9%) patients. At the time of infection, 50% were outpatients, 23% were inpatients on a general cardiology floor, and 27% were in the cardiac intensive care unit (CICU). Most patients (82%) were symptomatic at time of diagnosis, but only 13% required escalation of respiratory support, and 31% received SARS-CoV-2 therapies. Notably, no mortality occurred, and significant morbidity was rare after SARS-CoV-2 infection in pediatric patients on VAD support.

Interplay between driveline infection, vessel wall inflammation, cerebrovascular events and mortality in patients with left ventricular assist device

In patients with left ventricular assist device (LVAD), infections and thrombotic events represent severe complications. We investigated device-specific local and systemic inflammation and its impact on cerebrovascular events (CVE) and mortality. In 118 LVAD patients referred for 18F-FDG-PET/CT, metabolic activity of LVAD components, thoracic aortic wall, lymphoid and hematopoietic organs, was quantified and correlated with clinical characteristics, laboratory findings, and outcome. Driveline infection was detected in 92/118 (78%) patients by 18F-FDG-PET/CT. Activity at the driveline entry site was associated with increased signals in aortic wall (r = 0.32, p < 0.001), spleen (r = 0.20, p = 0.03) and bone marrow (r = 0.20, p = 0.03), indicating systemic interactions. Multivariable analysis revealed independent associations of aortic wall activity with activity of spleen (β = 0.43, 95% CI 0.18-0.68, p < 0.001) and driveline entry site (β = 0.04, 95% CI 0.01-0.06, p = 0.001). Twenty-two (19%) patients suffered CVE after PET/CT. In a binary logistic regression analysis metabolic activity at the driveline entry site missed the level of significance as an influencing factor for CVE after adjusting for anticoagulation (OR = 1.16, 95% CI 1-1.33, p = 0.05). Metabolic activity of the subcutaneous driveline (OR = 1.13, 95% CI 1.02-1.24, p = 0.016) emerged as independent risk factor for mortality. Molecular imaging revealed systemic inflammatory interplay between thoracic aorta, hematopoietic organs, and infected device components in LVAD patients, the latter predicting CVE and mortality.

Body mass index-dependent immunological profile changes after left ventricular assist device implantation

Purpose

Infection is a common complication following left ventricular assist device (LVAD) implantation. Patients with obesity are particularly at risk due to their high percentage of adipose tissue and the resulting chronic inflammatory state and resulting immunological changes. This study investigated changes of immunological parameters in relation to body mass index (BMI) during the first year after LVAD implantation.

Methods

Blood samples were obtained prior to LVAD implantation and at 3 (1st FU), 6 (2nd FU) and 12 mo (3rd FU) after LVAD implantation. Patients were divided into three groups (normal weight: BMI of 18.5-24.9 kg/m2; n=12; pre-obesity: 25.0-29.9 kg/m2; n=15; obesity: ≥ 30.0 kg/m2; n=17) based on their BMI at the time of LVAD implantation. Flow cytometric analyses for CD4+ and CD8+ T cells, regulatory T cells (Tregs), B cells as well as dendritic cells (DCs) were performed.

Results

After LVAD implantation, obese patients (0.51 ± 0.20%) showed a higher proportion of overall DCs than normal-weight (0.28 ± 0.10%) and pre-obese patients (0.32 ± 0.11%, p<0.01) at 3rd FU. The proportion of BDCA3+ myeloid DCs was lower in obese patients (64.3 ± 26.5%) compared to normal-weight patients (82.7 ± 10.0%, pnormal-weight vs. obesity=0.05) at 2nd FU after LVAD implantation. The analysis of BDCA4+ plasmacytoid DCs revealed a reduced proportion in pre-obese (21.1 ± 9.8%, pnormal-weight vs. pre-obesity=0.01) and obese patients (23.7 ± 10.6%, pnormal-weight vs. obesity=0.05) compared to normal-weight patients (33.1 ± 8.2%) in the 1st FU. T cell analysis showed that CD4+ T cells of obese patients (62.4 ± 9.0%) significantly increased in comparison to pre-obese patients (52.7 ± 10.0%, ppre-obesity vs. obesity=0.05) and CD8+ T cells were lower in obese patients (31.8 ± 8.5%) than in normal-weight patients (42.4 ± 14.2%; pnormal-weight vs. obesity=0.04) at the 3rd FU. Furthermore, we observed significantly reduced proportions of Tregs in pre-obese patients compared to normal-weight and obese patients at 2nd FU (p=0.02) and 3rd FU (p=0.01) after LVAD implantation.

Conclusion

This study reported changes of the innate and adaptive immune system of pre-obese and obese compared to normal-weight patients one year after LVAD implantation. DCs and their subsets, CD8+ T cells and Tregs were affected immune cell populations that indicate immunological changes which might increase the incidence of postoperative infection.

Bivalirudin Compared to Heparin as the Primary Anticoagulant in Pediatric Berlin Heart Recipients

Bivalirudin has been used in increasing frequency as an alternative to unfractionated heparin (UFH) in pediatric recipients of Berlin Heart EXCOR ventricular assist devices (VAD). This single-center, retrospective review characterizes anticoagulant trends and outcomes in pediatric Berlin Heart VAD recipients implanted between September 1, 2013, and August 31, 2021, anticoagulated with either bivalirudin or UFH. Thirty-one patients were included; 65% who received bivalirudin and 35% who received UFH. The median age was 2.9 years, included 64.5% females, with 61.3% of patients diagnosed with dilated cardiomyopathy and 25.8% of patients with congenital heart disease. Therapeutic anticoagulation was achieved sooner in the bivalirudin group compared to UFH via anti-Xa monitoring (median 5.7 and 69.5 hours, respectively, p < 0.001). Bivalirudin had a greater number of therapeutic values comparatively to UFH (52% and 24%, respectively; p < 0.001) and a superior number of hours in the therapeutic range (67% and 32%, respectively; p < 0.001). Secondary outcomes were similar among the two groups, apart from greater chest tube output (UFH), more frequent events of elevated plasma-free hemoglobin (bivalirudin), and more frequent elevated inflammatory markers postimplant (bivalirudin). Prevalence of pump replacements secondary to significant clot burden and prevalence of stroke was comparable. In this patient cohort, bivalirudin demonstrated greater anticoagulation stability comparatively to UFH. Multicenter collaboration would be necessary to identify whether this further translates into improved patient outcomes.

Managing Covid-19 in patients with heart failure: current status and future prospects

INTRODUCTION

COVID-19 may contribute to decompensation of previously stable chronic HF or cause a de-novo heart failure, which may come from the hyperinflammatory response and subsequent increase in metabolic demand.

AREAS COVERED

Two independent investigators searched MEDLINE (via PubMed), Europe PMC, and ScienceDirect databases with the following search terms: COVID-19, heart failure, COVID-19 drugs, heart failure drugs, and device therapy. All of the included full-text articles were rigorously evaluated by both authors in case there was disagreement about whether research should be included or not. In total, 157 studies were included and underwent extensive reading by the authors.

EXPERT OPINION

The World Health Organization (WHO) and the National Institute of Health (NIH) have published COVID-19 drug recommendations, although recommendations for HF-specific drug choices in COVID-19 are still lacking. We hope that this review can answer the void of comprehensive research data regarding the management options of HF in the COVID-19 condition so that clinicians can at least choose a more beneficial therapy or avoid combination therapies that have a high burden of side effects on HF; thus, morbidity and mortality in COVID-19 patients with HF may be reduced.

Advanced strategies to thwart foreign body response to implantable devices

Mitigating the foreign body response (FBR) to implantable medical devices (IMDs) is critical for successful long-term clinical deployment. The FBR is an inevitable immunological reaction to IMDs, resulting in inflammation and subsequent fibrotic encapsulation. Excessive fibrosis may impair IMDs function, eventually necessitating retrieval or replacement for continued therapy. Therefore, understanding the implant design parameters and their degree of influence on FBR is pivotal to effective and long lasting IMDs. This review gives an overview of FBR as well as anti-FBR strategies. Furthermore, we highlight recent advances in biomimetic approaches to resist FBR, focusing on their characteristics and potential biomedical applications.

De novo human leukocyte antigen allosensitization patterns in patients bridged to heart transplantation using left ventricular assist devices

INTRODUCTION

We examined the impact and time course of de novo human leukocyte antigen (HLA) allosensitization following left ventricular assist device (LVAD) implantation.

METHODS AND RESULTS

Forty patients had a calculated panel reactive antibody (cPRA) prior to LVAD surgery between January 2014 and December 2018. Of these patients, we retrospectively studied 33 patients who had pre-LVAD cPRA <10%. De novo allosensitization was defined as cPRA ≥10% within 3 months following LVAD surgery, and "persistent allosensitization" was defined as cPRA ≥10% at time of heart transplant or death. One-third (11/33) of our cohort developed de novo allosensitization within 3-months post-LVAD. Median duration of follow-up during LVAD support was 588 days (IQR 337-1071 days), or approximately 19 months. In an adjusted, multivariable analysis, female sex remained associated with de novo allosensitization (adjusted odds ratio [95%CI]: 11 (1.4-85), P = 0.026). De novo allosensitization was subsequently associated with persistent allosensitization (P = 0.024). Both axial-flow and centrifugal-flow LVADs had similar rates of allosensitization. Compared to those with no allosensitization, patients with de novo allosensitization did not appear to have inferior post-transplant outcomes of death or treated rejection.

CONCLUSION

In our single-center experience, one-third of patients developed de novo allosensitization which did not appear to associate with inferior post-transplant outcomes. Female sex was associated with de novo allosensitization.

Neutrophil dysfunction due to continuous mechanical shear exposure in mechanically assisted circulation in vitro

OBJECTIVE

Leukocytes play an important role in the body's immune system. The aim of this study was to assess alterations in neutrophil phenotype and function in pump-assisted circulation in vitro.

METHODS

Human blood was circulated for four hours in three circulatory flow loops with a CentriMag blood pump operated at a flow of 4.5 L/min at three rotational speeds (2100, 2800, and 4000 rpm), against three pressure heads (75, 150, and 350 mm Hg), respectively. Blood samples were collected hourly for analyses of neutrophil activation state (Mac-1, CD62L, CD162), neutrophil reactive oxygen species (ROS) production, apoptosis, and neutrophil phagocytosis.

RESULTS

Activated neutrophils indicated by both Mac-1 expression and decreased surface expression of CD62L and CD162 receptors increased with time in three loops. The highest level of neutrophil activation was observed in the loop with the highest rotational speed. Platelet-neutrophil aggregates (PNAs) progressively increased in two loops with lower rotational speeds. PNAs peaked at one hour after circulation and decreased subsequently in the loop with the highest rotational speed. Neutrophil ROS production dramatically increased at one hour after circulation and decreased subsequently in all three loops with similar levels and trends. Apoptotic neutrophils increased with time in all three loops. Neutrophil phagocytosis capacity in three loops initially elevated at one hour after circulation and decreased subsequently. Apoptosis and altered phagocytosis were dependent on rotational speed.

CONCLUSIONS

Our study revealed that the pump-assisted circulation induced neutrophil activation, apoptosis, and functional impairment. The alterations were strongly associated with pump operating condition and duration.

The Role of Endothelium in COVID-19

The 2019 novel coronavirus, known as severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), is causing a global pandemic. The virus primarily affects the upper and lower respiratory tracts and raises the risk of a variety of non-pulmonary consequences, the most severe and possibly fatal of which are cardiovascular problems. Data show that almost one-third of the patients with a moderate or severe form of COVID-19 had preexisting cardiovascular comorbidities such as diabetes mellitus, obesity, hypertension, heart failure, or coronary artery disease. SARS-CoV2 causes hyper inflammation, hypoxia, apoptosis, and a renin-angiotensin system imbalance in a variety of cell types, primarily endothelial cells. Profound endothelial dysfunction associated with COVID-19 can be the cause of impaired organ perfusion that may generate acute myocardial injury, renal failure, and a procoagulant state resulting in thromboembolic events. We discuss the most recent results on the involvement of endothelial dysfunction in the pathogenesis of COVID-19 in patients with cardiometabolic diseases in this review. We also provide insights on treatments that may reduce the severity of this viral infection.

Initial experience with CytoSorb therapy in patients receiving left ventricular assist devices

BACKGROUND

The use of left ventricular assist devices (LVAD) in patients with advance heart failure is still associated with an important risk of immune dysregulation and infections. The aim of this study was to determine whether extracorporeal blood purification using the CytoSorb device benefits patients after LVAD implantation in terms of complications and overall survival.

MATERIALS AND METHODS

Between August 2010 and January 2020, 207 consecutive patients underwent LVAD implantation, of whom 72 underwent CytoSorb therapy and 135 did not. Overall survival, major adverse events, and laboratory parameters were compared between 112 propensity score-matched patients (CytoSorb: 72 patients; non-CytoSorb: 40 patients).

RESULTS

WBC (p = .033), CRP (p = .001), and IL-6 (p < .001), significantly increased with LVAD implantation, while CytoSorb did not influence this response. In-hospital mortality and overall survival during follow-up were similar with CytoSorb. However, patients treated with CytoSorb were more likely to develop respiratory failure (54.2% vs. 30.0%, p = .024), need mechanical ventilation for longer than 6 days post-implant (50.0% vs. 27.5%, p = .035), and require tracheostomy during hospitalization (31.9% vs. 12.5%, p = .040). No other significant differences were observed with regard to major adverse events during follow-up.

CONCLUSIONS

Overall, our results showed that CytoSorb might not convey a significant morbidity or mortality benefit for patients undergoing LVAD implantation.

In-depth review of cardiopulmonary support in COVID-19 patients with heart failure

Coronavirus disease 2019 infection has spread worldwide and causing massive burden to our healthcare system. Recent studies show multiorgan involvement during infection, with direct insult to the heart. Worsening of the heart function serves as a predictor of an adverse outcome. This finding raises a particular concern in high risk population, such as those with history of preexisting heart failure with or without implantable device. Lower baseline and different clinical characteristic might raise some challenge in managing either exacerbation or new onset heart failure that might occur as a consequence of the infection. A close look of the inflammatory markers gives an invaluable clue in managing this condition. Rapid deterioration might occur anytime in this setting and the need of cardiopulmonary support seems inevitable. However, the use of cardiopulmonary support in this patient is not without risk. Severe inflammatory response triggered by the infection in combination with the preexisting condition of the worsening heart and implantable device might cause a hypercoagulability state that should not be overlooked. Moreover, careful selection and consideration have to be met before selecting cardiopulmonary support as a last resort due to limited resource and personnel. By knowing the nature of the disease, the interaction between the inflammatory response and different baseline profile in heart failure patient might help clinician to salvage and preserve the remaining function of the heart.

Impact of Preoperative Lymphopenia on Survival Following Left Ventricular Assist Device Placement

Lymphopenia has been implicated in poor outcomes in the heart failure population. However, the prognostic implication of lymphopenia in left ventricular assist device (LVAD) patients is unknown. We examine the impact of lymphopenia on all-cause mortality in this population over a 24-month period post-implantation. A total of 170 patients between June 2011 and July 2018 receiving permanent durable LVAD at a single center formed the study population. Criteria for lymphopenia on admission, defined as an absolute lymphocyte count (ALC) <1500 cells/μl, was met in 99 patients. A total of 11 patients were excluded: two with ALC >4800/μl and nine with incomplete data. Survival across groups was compared with a Kaplan-Meier plot and log-rank statistics. The Cox proportional hazard model was used to examine the association between lymphopenia and 24-month all-cause mortality. In the lymphopenia group, mean ALC was 909.6 ± 331.9 versus 2073.6 ± 501.1 in the non-lymphopenic group. Twenty-four-month all-cause mortality was significantly higher in the lymphopenia group (p = 0.009). The lymphopenic patients had worse unadjusted (hazard ratio [HR] = 2.14, confidence interval [CI] = 1.19-3.82; p = 0.01) and adjusted survival (HR = 2.07, CI = 1.13-3.79; p = 0.02). Further clinical investigations are required to assess the utility of continued clinical monitoring of ALC levels beyond LVAD placement.

Reactivation of Cytomegalovirus Following Left Ventricular Assist Device Implantation: A Case-Control Study

While cytomegalovirus (CMV) reactivation occurs in immunocompetent patients who are critically ill and has been associated with worse outcomes, very few cases of CMV reactivation have been reported following left ventricular assist device (LVAD) implantation. We aimed to evaluate the incidence and risk factors for CMV reactivation following LVAD implantation. Retrospective chart review of patients who had undergone LVAD implantation between July 2004 and December 2018 was performed. Cases with CMV reactivation post-LVAD were randomly matched (1:2) by sex, LVAD type, and implant year with controls utilizing SAS macros. Fisher's exact and paired sample t-tests were performed to evaluate for differences between categorical and continuous variables, respectively. Days to reactivation post-LVAD implantation were calculated in cases, and the corresponding times post-LVAD implantation were determined in control patients for variable comparisons. Survival analysis was performed using the Kaplan-Meier method. Of the 349 patients reviewed, 208 (59.6%) patients were seropositive for CMV before LVAD implantation. Of these 208 patients, eight (3.8%) had CMV reactivation following LVAD implantation. The median time to CMV reactivation following LVAD implantation was 21.5 days (range, 6-177). Six (75%) patients had CMV viremia, and the other two had colitis and pneumonia without viremia. In comparison to controls, patients with CMV had higher creatinine levels (p = 0.039) and higher RDW (p = 0.05) and were more likely to have received steroids within the previous week (p = 0.028) and to have concurrent bacterial infection (p = 0.001). CMV reactivation following LVAD implantation is more frequent than expected. Early testing, diagnosis, and treatment in at-risk patients (i.e., renal failure, steroid use, elevated RDW) might improve clinical outcomes.

IgA Vasculitis With Henoch-Schönlein Purpura as an Immune Complication Associated With Left Ventricle Assist Device Insertion

The implantation of left ventricular assist devices (LVADs) in patients with end-stage heart failure can be associated with some forms of immune dysregulation and systemic inflammatory response. These abnormalities may be related to impaired T-lymphocyte-dependent immunity and B-lymphocyte hyper-reactivity and may lead to the development of autoimmune processes and the occurrence of severe infections. We present here the first observation of a peculiar immune complication associated with the implantation of an LVAD, characterized by an IgA vasculitis clinically manifested as Henoch-Schönlein purpura. The vasculitis was biologically associated with a significant increase of the plasma levels of C-X-C motif chemokine ligand (CXCL)13, a CXC motif chemokine produced by follicular dendritic cells, which targets CXCR5, a receptor primarily expressed by B lymphocytes, to promote their chemotaxis and expansion. Spontaneous resolution of the vasculitis occurred over time, concomitantly to a decrease of CXCL13 expression. These findings suggest that CXCL13 might be an interesting biomarker to detect auto-antigen sampling and the risk of secondary immune complications following LVAD implantation.

Factors associated with neutropenia post heart transplantation

BACKGROUND

Neutropenia is a serious complication following heart transplantation (OHT); however, risk factors for its development and its association with outcomes is not well described. We sought to study the prevalence of neutropenia, risk factors associated with its development, and its impact on infection, rejection, and survival.

METHODS

A retrospective single-center analysis of adult OHT recipients from July 2004 to December 2017 was performed. Demographic, laboratory, medication, infection, rejection, and survival data were collected for 1 year post-OHT. Baseline laboratory measurements were collected within the 24 hours before OHT. Neutropenia was defined as absolute neutrophil count ≤1000 cells/mm3. Cox proportional hazards models explored associations with time to first neutropenia. Associations between neutropenia, analyzed as a time-dependent covariate, with secondary outcomes of time to infection, rejection, or death were also examined.

RESULTS

Of 278 OHT recipients, 84 (30%) developed neutropenia at a median of 142 days (range 81-228) after transplant. Factors independently associated with increased risk of neutropenia included lower baseline WBC (HR 1.12; 95% CI 1.11-1.24), pre-OHT ventricular assist device (1.63; 1.00-2.66), high-risk CMV serostatus [donor positive, recipient negative] (1.86; 1.19-2.88), and having a previous CMV infection (4.07; 3.92-13.7).

CONCLUSIONS

Neutropenia is a fairly common occurrence after adult OHT. CMV infection was associated with subsequent neutropenia, however, no statistically significant differences in outcomes were found between neutropenic and non-neutropenic patients in this small study. It remains to be determined in future studies if medication changes in response to neutropenia would impact patient outcomes.

How Are We Monitoring Brain Injuries in Patients With Left Ventricular Assist Device? A Systematic Review of Literature

Despite the common occurrence of brain injury in patients with left ventricular assist device (LVAD), optimal neuromonitoring methods are unknown. A systematic review of PubMed and six electronic databases from inception was conducted until June 5, 2019. Studies reporting methods of neuromonitoring while on LVAD were extracted. Of 5,190 records screened, 37 studies met the inclusion criteria. The neuromonitoring methods include Transcranial Doppler ultrasound for emboli monitoring (TCD-e) (n = 13) and cerebral autoregulation (n = 3), computed tomography and magnetic resonance imaging (n = 9), serum biomarkers (n = 7), carotid ultrasound (n = 3), and near-infrared spectroscopy (n = 2). Of 421 patients with TCD-e, thromboembolic events (TEs) were reported in 79 patients (20%) and microembolic signals (MES) were detected in 105 patients (27%). Ischemic stroke was more prevalent in patients with MES compared to patients without MES (43% vs.13%, p < 0.001). Carotid ultrasound for assessing carotid stenosis was unreliable after LVAD implantation. Elevated lactate dehydrogenase (LDH) levels were associated with TEs. Significant heterogeneity exists in timing, frequency, and types of neuromonitoring tools. TCD-e and serial LDH levels appeared to have potential for assessing the risk of ischemic stroke. Future prospective research incorporating protocolized TCD-e and LDH may assist in monitoring adverse events in patients with LVAD.

Device-Induced Hemostatic Disorders in Mechanically Assisted Circulation

Mechanically assisted circulation (MAC) sustains the blood circulation in the body of a patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) or on ventricular assistance with a ventricular assist device (VAD) or on extracorporeal membrane oxygenation (ECMO) with a pump-oxygenator system. While MAC provides short-term (days to weeks) support and long-term (months to years) for the heart and/or lungs, the blood is inevitably exposed to non-physiological shear stress (NPSS) due to mechanical pumping action and in contact with artificial surfaces. NPSS is well known to cause blood damage and functional alterations of blood cells. In this review, we discussed shear-induced platelet adhesion, platelet aggregation, platelet receptor shedding, and platelet apoptosis, shear-induced acquired von Willebrand syndrome (AVWS), shear-induced hemolysis and microparticle formation during MAC. These alterations are associated with perioperative bleeding and thrombotic events, morbidity and mortality, and quality of life in MCS patients. Understanding the mechanism of shear-induce hemostatic disorders will help us develop low-shear-stress devices and select more effective treatments for better clinical outcomes.

Heart failure and COVID-19

Heart failure is a common disease state that can be encountered at different stages in the course of a COVID-19 patient presentation. New or existing heart failure in the setting of COVID-19 can present a set of unique challenges that can complicate presentation, management, and prognosis. A careful understanding of the hemodynamic and diagnostic implications is essential for appropriate triage and management of these patients. Abnormal cardiac biomarkers are common in COVID-19 and can stem from a variety of mechanisms that involve the viral entry itself through the ACE2 receptors, direct cardiac injury, increased thrombotic activity, stress cardiomyopathy, and among others. The cytokine storm observed in this pandemic can be a culprit in many of the observed mechanisms and presentations. A correct understanding of the two-way interaction between heart failure medications and the infection as well as the proposed COVID-19 medications and heart failure can result in optimal management. Guideline-directed medical therapy for heart failure should not be interrupted for theoretical concerns but rather based on tolerance and clinical presentation. Initiating specific cardiac or heart failure medications to prevent the infection or mitigate the disease is also not an evidence-based practice at this time. Heart failure patients on advanced therapies including those with heart transplantation will particularly benefit from involving the advanced heart failure team members in the overall management if they contract the virus.

The Degree of Cardiac Remodelling before Overload Relief Triggers Different Transcriptome and miRome Signatures during Reverse Remodelling (RR)-Molecular Signature Differ with the Extent of RR

This study aims to provide new insights into transcriptome and miRome modifications occurring in cardiac reverse remodelling (RR) upon left ventricle pressure-overload relief in mice. Pressure-overload was established in seven-week-old C57BL/6J-mice by ascending aortic constriction. A debanding (DEB) surgery was performed seven weeks later in half of the banding group (BA). Two weeks later, cardiac function was evaluated through hemodynamics and echocardiography, and the hearts were collected for histology and small/bulk-RNA-sequencing. Pressure-overload relief was confirmed by the normalization of left-ventricle-end-systolic-pressure. DEB animals were separated into two subgroups according to the extent of cardiac remodelling at seven weeks and RR: DEB1 showed an incomplete RR phenotype confirmed by diastolic dysfunction persistence (E/e' ≥ 16 ms) and increased myocardial fibrosis. At the same time, DEB2 exhibited normal diastolic function and fibrosis, presenting a phenotype closer to myocardial recovery. Nevertheless, both subgroups showed the persistence of cardiomyocytes hypertrophy. Notably, the DEB1 subgroup presented a more severe diastolic dysfunction at the moment of debanding than the DEB2, suggesting a different degree of cardiac remodelling. Transcriptomic and miRomic data, as well as their integrated analysis, revealed significant downregulation in metabolic and hypertrophic related pathways in DEB1 when compared to DEB2 group, including fatty acid β-oxidation, mitochondria L-carnitine shuttle, and nuclear factor of activated T-cells pathways. Moreover, extracellular matrix remodelling, glycan metabolism and inflammation-related pathways were up-regulated in DEB1. The presence of a more severe diastolic dysfunction at the moment of pressure overload-relief on top of cardiac hypertrophy was associated with an incomplete RR. Our transcriptomic approach suggests that a cardiac inflammation, fibrosis, and metabolic-related gene expression dysregulation underlies diastolic dysfunction persistence after pressure-overload relief, despite left ventricular mass regression, as echocardiographically confirmed.

Gastrointestinal Bleeding as a Complication in Continuous Flow Ventricular Assist Devices: A Systematic Review With Meta-Analysis

Background

The use of ventricular assist devices (VADs) has become predominant in this era of medicine. It is commonly used as a bridge to transplant, recovery and as a destination therapy for patients with severe heart failure, who are not responsive to maximum optimal management or ineligible for transplant. However, several complications are known to occur with the use of these devices. In this research, we will compare gastrointestinal bleeding in patients who used centrifugal flow versus axial flow VADs. We hope that the result of this meta-analysis and the review presented provide adequate information to future researchers, physicians and other healthcare professionals who are interested in this topic.

Methods

Published articles evaluated for inclusion were obtained from MEDLINE (PubMed), Cochrane, EBSCO, clinicaltrials.gov, and international clinical trials registry. This research was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Procured articles were reviewed by two independent reviewers. Only randomized control trials and observational studies were used. Quality assessment was done with Cochrane Collaboration’s tool (RoB.2 with visualization through robviz) and Newcastle-Ottawa Scale (NOS). Data analysis was carried out with the use of R data analysis tool (version 4.0.0; release date: April 24th, 2020).

Results

At the end of this meta-analysis, the occurrence of gastrointestinal bleeding was not significantly different between both groups; with odds ratio (OR): 0.81; 95% confidence interval (CI): 0.65 - 1.00; P value = 0.05. Between-study variance (Tau-squared) was zero (0), standard error (SE) = 0.06. The degree of heterogeneity measured with I-squared statistic was 0% (minimal). Egger’s regression test was not statistically significant, P = 0.93. Symmetry of distribution was observed on the funnel plot. Trim and fill analysis showed no missing studies on the left; SE = 1.68.

Conclusions

The result obtained from this research indicates that the occurrence of gastrointestinal bleeding is not significantly different in both groups of patients, irrespective of the type of continuous flow VAD used. Although, the study sample used in this meta-analysis was limited.

Considerations for Heart Failure Care During the COVID-19 Pandemic

The coronavirus-2019 (COVID-19) infection pandemic has affected the care of patients with heart failure (HF) who have contracted COVID-19 as well as those without COVID-19 who have been impacted by the restructuring of health care delivery. Patients with HF and other cardiovascular comorbidities are at risk for severe disease and complications of infection. Similarly, COVID-19 has been demonstrated to cause myocarditis and may be implicated in new-onset cardiomyopathy. During this pandemic, special considerations are needed for patients with advanced HF, including those supported by durable left ventricular assist devices (LVADs) and heart transplant recipients. The purpose of this review is to summarize emerging data regarding the development of HF secondary to COVID-19 infection in patients with advanced HF and the implications of the pandemic for care of uninfected patients with HF.

Proteomic Signatures During Treatment in Different Stages of Heart Failure

Background:

Proteomics have already provided novel insights into the pathophysiology of heart failure (HF) with reduced ejection fraction. Previous studies have evaluated cross-sectional protein signatures of HF, but few have characterized proteomic changes following HF with reduced ejection fraction treatment with ARNI (angiotensin receptor/neprilysin inhibitor) therapy or left ventricular assist devices.

Methods:

In this retrospective omics study, we performed targeted proteomics (N=625) of whole blood sera from patients with American College of Cardiology/American Heart Association stage D (N=29) and stage C (N=12) HF using proximity extension assays. Samples were obtained before and after (median=82 days) left ventricular assist device implantation (stage D; primary analysis) and ARNI therapy initiation (stage C; matched reference). Oblique principal component analysis and point biserial correlations were used for feature extraction and selection; standardized mean differences were used to assess within and between-group differences; and enrichment analysis was used to generate and cluster Gene Ontology terms.

Results:

Core sets of proteins were identified for stage C (N=9 proteins) and stage D (N=18) HF; additionally, a core set of 5 shared HF proteins (NT-proBNP [N-terminal pro-B type natriuretic peptide], ESM [endothelial cell-specific molecule]-1, cathepsin L1, osteopontin, and MCSF-1) was also identified. For patients with stage D HF, moderate (δ, 0.40–0.60) and moderate-to-large (δ, 0.60–0.80) sized differences were observed in 8 of their 18 core proteins after left ventricular assist devices implantation. Additionally, specific protein groups reached concentration levels equivalent ( g <0.10) to stage C HF after initiation on ARNI therapy.

Conclusions:

HF with reduced ejection fraction severity associates with distinct proteomic signatures that reflect underlying disease attributes; these core signatures may be useful for monitoring changes in cardiac function following initiation on ARNI or left ventricular assist device implantation.

The Imperfect Cytokine Storm: Severe COVID-19 With ARDS in a Patient on Durable LVAD Support

As health systems worldwide grapple with the coronavirus disease-2019 (COVID-19) pandemic, patients with durable LVAD support represent a unique population at risk for the disease. This paper outlines the case of such a patient who developed COVID-19 complicated by a "cytokine storm" with severe acute respiratory distress syndrome and myocardial injury and describes the challenges that arose during management.

Predisposition or Protection?: COVID-19 in a Patient on LVAD Support With HIV/AIDS

There is a desperate search to discover effective therapies against coronavirus disease-2019 (COVID-19). Patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) comprise a unique population whose clinical course may provide insights into the effects of antiretroviral therapy on COVID-19. We describe the case of a patient with HIV/AIDS on left ventricular assist device support who was hospitalized and recovered from COVID-19. (Level of Difficulty: Intermediate.)

Thrombogenic and Inflammatory Reactions to Biomaterials in Medical Devices

Blood-contacting medical devices of different biomaterials are often used to treat various cardiovascular diseases. Thrombus formation is a common cause of failure of cardiovascular devices. Currently, there are no clinically available biomaterials that can totally inhibit thrombosis under the more challenging environments (e.g., low flow in the venous system). Although some biomaterials reduce protein adsorption or cell adhesion, the issue of biomaterial associated with thrombosis and inflammation still exists. To better understand how to develop more thrombosis-resistant medical devices, it is essential to understand the biology and mechano-transduction of thrombus nucleation and progression. In this review, we will compare the mechanisms of thrombus development and progression in the arterial and venous systems. We will address various aspects of thrombosis, starting with biology of thrombosis, mathematical modeling to integrate the mechanism of thrombosis, and thrombus formation on medical devices. Prevention of these problems requires a multifaceted approach that involves more effective and safer thrombolytic agents but more importantly the development of novel thrombosis-resistant biomaterials mimicking the biological characteristics of the endothelium and extracellular matrix tissues that also ameliorate the development and the progression of chronic inflammation as part of the processes associated with the detrimental generation of late thrombosis and neo-atherosclerosis. Until such developments occur, engineers and clinicians must work together to develop devices that require minimal anticoagulants and thrombolytics to mitigate thrombosis and inflammation without causing serious bleeding side effects.

BloodSurf 2017: News from the blood-biomaterial frontier

From stents and large-diameter vascular grafts, to mechanical heart valves and blood pumps, blood-contacting devices are enjoying significant clinical success owing to the application of systemic antiplatelet and anticoagulation therapies. On the contrary, research into material and device hemocompatibility aimed at alleviating the need for systemic therapies has suffered a decline. This research area is undergoing a renaissance fueled by recent fundamental insights into coagulation and inflammation that are offering new avenues of investigation, the growing recognition of the limitations facing existing therapeutic approaches, and the severity of the cardiovascular disorders epidemic. This Opinion article discusses clinical needs for hemocompatible materials and the emerging research directions for fulfilling those needs. Based on the 2017 BloodSurf conference that brought together clinicians, scientists, and engineers from academia, industry, and regulatory bodies, its purpose is to draw the attention of the wider clinical and scientific community to stimulate further growth. STATEMENT OF SIGNIFICANCE: The article highlights recent fundamental insights into coagulation, inflammation, and blood-biomaterial interactions that are fueling a renaissance in the field of material hemocompatibility. It will be useful for clinicians, scientists, engineers, representatives of industry and regulatory bodies working on the problem of developing hemocompatible materials and devices for treating cardiovascular disorders.