The International Society of Heart and Lung Transplantation Guidelines for the care of heart transplant recipients

Recombinant human IL-37 attenuates acute cardiac allograft rejection in mice

BACKGROUND

Allograft rejection remains a major obstacle to long-term graft survival. Although previous studies have demonstrated that IL-37 exhibited significant immunomodulatory effects in various diseases, research on its role in solid organ transplantation has not been fully elucidated. In this study, the therapeutic effect of recombinant human IL-37 (rhIL-37) was evaluated in a mouse cardiac allotransplantation model.

METHODS

The C57BL/6 recipients mouse receiving BALB/c donor hearts were treated with rhIL-37. Graft pathological and immunohistology changes, immune cell populations, and cytokine profiles were analyzed on postoperative day (POD) 7. The proliferative capacities of Th1, Th17, and Treg subpopulations were assessed in vitro. Furthermore, the role of the p-mTOR pathway in rhIL-37-induced CD4+ cell inhibition was also elucidated.

RESULTS

Compared to untreated groups, treatment of rhIL-37 achieved long-term cardiac allograft survival and effectively alleviated allograft rejection indicated by markedly reduced infiltration of CD4+ and CD11c+ cells and ameliorated graft pathological changes. rhIL-37 displayed significantly less splenic populations of Th1 and Th17 cells, as well as matured dendritic cells. The percentages of Tregs in splenocytes were significantly increased in the therapy group. Furthermore, rhIL-37 markedly decreased the levels of TNF-α and IFN-γ, but increased the level of IL-10 in the recipients. In addition, rhIL-37 inhibited the expression of p-mTOR in CD4+ cells of splenocytes. In vitro, similar to the in vivo experiments, rhIL-37 caused a decrease in the proportion of Th1 and Th17, as well as an increase in the proportion of Treg and a reduction in p-mTOR expression in CD4+ cells.

CONCLUSIONS

We demonstrated that rhIL-37 effectively suppress acute rejection and induce long-term allograft acceptance. The results highlight that IL-37 could be novel and promising candidate for prevention of allograft rejection.

Rejection Surveillance After Heart Transplantation: Is Paired Noninvasive Testing the New Gold Standard?

Rejection surveillance after heart transplantation has traditionally relied on numerous endomyocardial biopsies, most of which occur during the first posttransplant year. With the introduction of gene expression profiling and, more recently, donor-derived cell-free DNA, a great proportion of surveillance is being performed noninvasively with both tests. Although patients have welcomed the use of paired testing because of the decreased risk and inconvenience, interpretation of both tests can sometimes be challenging, particularly when the test results are discordant. Growing evidence from both single-center experiences and large national databases has given insights that have allowed the field to operationalize dual testing and provide physicians with algorithms to approach paired testing. The increased use of noninvasive testing has also begun to challenge the role of biopsy as the gold standard for graft monitoring, not only for rejection but over the life of the heart transplant. In a growing number of circumstances, cell-free DNA not only may be a better means of assessing rejection but could also redefine how clinicians approach the diagnosis and even treatment of graft injury. As the heart transplant community garners more experience and generates more data, the current paradigms of heart transplant surveillance will continue to be challenged.

Graft protective effects and donor-specific antibody suppression by CD4+CD25+Foxp3+ regulatory T cell induced by HMG-CoA reductase inhibitor rosuvastatin in a murine heart transplant model

BACKGROUND

We previously demonstrated that the hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitor (statins) play an important role in the regulation of alloimmune responses. However, little is known regarding the effects of statin on allograft protection or donor-specific antibodies (DSA). In this study, we investigated the graft-protective and immunomodulatory effects of rosuvastatin in a model of fully major histocompatibility complex-mismatched murine cardiac allograft transplantation.

METHODS

CBA mice underwent transplantation of C57BL/6 (B6) hearts and received 50 and 500 μg/kg/day of rosuvastatin from the day of transplantation until seven days after the completion of transplantation. To confirm the requirement for regulatory T cells (Tregs), we administered an anti-interleukin-2 receptor alpha antibody (PC-61) to rosuvastatin-treated CBA recipients. Additionally, histological and fluorescent staining, cell proliferation analysis, flow cytometry, and DSA measurements were performed.

RESULTS

CBA recipients with no treatment rejected B6 cardiac graft acutely (median survival time [MST], 7 days). CBA mice treated with 500 μg/kg/day of rosuvastatin prolonged allograft survival (MSTs, 77 days). Fluorescent staining studies showed that rosuvastatin-treated recipients had strong aggregation of CD4+Foxp3+ cells in the myocardium and around the coronary arteries of cardiac allografts two weeks after grafting. Flow cytometry studies performed two weeks after transplantation showed an increased number of splenic CD4+CD25+Foxp3+ T cells in rosuvastatin-treated recipients. The addition of rosuvastatin to mixed leukocyte cultures suppressed cell proliferation by increasing the number of CD4+CD25+Foxp3+ Tregs. Additionally, Tregs suppressed DSA production in rosuvastatin-treated recipients.

CONCLUSION

Rosuvastatin treatment may be a complementary graft-protective strategy for suppressing DSA production in the acute phase, driven by the promotion of splenic and graft-infiltrating CD4+CD25+Foxp3+ Tregs.

Speckle-Tracking Echocardiography in Right Ventricular Function of Clinically Well Patients with Heart Transplantation

Heart transplantation (HT) is the mainstream therapy for end-stage heart disease. However, the cardiac graft function can be affected by several factors. It is important to monitor HT patients for signs of graft dysfunction. Transthoracic echocardiography is a simple, first-line, and non-invasive method for the assessment of cardiac function. The emerging speckle-tracking echocardiography (STE) could quickly and easily provide additive information over traditional echocardiography. STE longitudinal deformation parameters are markers of early impairment of ventricular function. Although once called the "forgotten ventricle", right ventricular (RV) assessment has gained attention in recent years. This review highlights the potentially favorable role of STE in assessing RV systolic function in clinically well HT patients.

Prevention and rehabilitation after heart transplantation: A clinical consensus statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus.

Sex and Gender-related Disparities in Clinical Characteristics and Outcomes in Heart Transplantation

PURPOSE OF REVIEW

Limited research has been conducted on sex disparities in heart transplant (HT). The aim of this review is to analyse the available evidence on the influence of sex and gender-related determinants in the entire HT process, as well as to identify areas for further investigation.

RECENT FINDINGS

Although women make up half of the population affected by heart failure and related mortality, they account for less than a third of HT recipients. Reasons for this inequality include differences in disease course, psychosocial factors, concerns about allosensitisation, and selection or referral bias in female patients. Women are more often listed for HT due to non-ischaemic cardiomyopathy and have a lower burden of cardiovascular risk factors. Although long-term prognosis appears to be similar for both sexes, there are significant disparities in post-HT morbidity and causes of mortality (noting a higher incidence of rejection in women and of malignancy and cardiac allograft vasculopathy in men). Additional research is required to gain a better understanding of the reasons behind gender disparities in eligibility and outcomes following HT. This would enable the fair allocation of resources and enhance patient care.

Cardiac magnetic resonance imaging in heart transplant recipients with biopsy-negative graft dysfunction

AIMS

Graft dysfunction (GD) after heart transplantation (HTx) can develop without evidence of cell- or antibody-mediated rejection. Cardiac magnetic resonance imaging (CMR) has an evolving role in detecting rejection; however, its role in biopsy-negative GD has not been described. This study examines CMR findings, evaluates outcomes based on CMR results, and seeks to identify the possibility of rejection missed through endomyocardial biopsy by using CMR in HTx recipients with biopsy-negative GD.

METHODS AND RESULTS

HTx recipients with GD [defined as a decrease in left ventricular ejection fraction (LVEF) by >5% and LVEF < 50%] in the absence of rejection by biopsy or allograft vasculopathy and who underwent CMR were included in the study. The primary outcome was a composite of all-cause mortality, re-transplantation, or persistent LVEF < 50%. Overall, 34 HTx recipients developed biopsy-negative GD and underwent CMR. Left ventricular late gadolinium enhancement (LGE) on CMR was observed in 16 patients with two distinct patterns: diffuse epicardial (n = 13) and patchy (n = 3) patterns. Patients with LGE developed GD later after HTx [4 (1.4-6.8) vs. 0.8 (0.3-1.2) years, P < 0.001], were more often symptomatic (88% vs. 56%, P = 0.06), and had greater haemodynamic derangement (pulmonary capillary wedge pressure: 19 ± 7 vs. 13 ± 3 mmHg, P = 0.002) as compared with those without LGE. No significant difference was observed in the primary composite outcome between patients with LGE and those without LGE (50% vs. 38% of patients with events, P = 0.515). During a median follow-up of 3.8 years, mean LVEF improved similarly in the LGE-negative (37-55%) and LGE-positive groups (32-55%) (P = 0.16).

CONCLUSIONS

Biopsy-negative GD occurs with and without LGE when assessed by CMR, indicative of possible rejection/inflammation occurring only in a subset of patients. Irrespective of LGE, LVEF improvement occurs in most GD patients, suggesting that other neurohormonal or immunomodulatory mechanisms may also contribute to GD development.

The efficacy and safety of sodium-glucose cotransporter-2 inhibitors in solid organ transplant recipients: A scoping review

Sodium glucose co-transporter 2 (SGLT2) inhibitors are used for the treatment of diabetes and for their cardiovascular and kidney benefits in patients with or without diabetes. Use in solid organ transplant recipients is controversial because transplant recipients were excluded from the major clinical trials assessing SGLT2 inhibitors. The goal of this review was to assess the available literature regarding the use of SGLT2 inhibitors in solid organ transplant recipients. A PubMed search was conducted for studies published in English through December 31, 2023. Studies were excluded if they were meta-analyses, review articles, commentaries, single case reports, or in vitro studies, or did not involve the use of SGLT2 inhibitors in solid organ transplant recipients with a diabetic, cardiovascular, or kidney outcome being assessed. In the final review, 20 studies were included: kidney (n = 15), heart (n = 4), and liver/lung/kidney (n = 1) transplant recipients. SGLT2 inhibitors had similar A1c reduction efficacy and were found to be weight neutral with possible weight reduction effects. Cardiovascular and kidney outcomes were not adequately assessed in the available studies. Adverse effects were reported to occur at a similar rate in transplant recipients compared to the general population. SGLT2 inhibitors were initiated ≥1-year post-transplant in most transplant recipients included in these studies. The overall safety and antihyperglycemic efficacy of SGLT2 inhibitors in kidney and heart transplant recipients is similar to the general population. Data assessing SGLT2 inhibitors use in solid organ transplant recipients for longer durations are needed.

"Take it or leave it": Analysis of pediatric heart offers for transplantation in Switzerland

BACKGROUND

There is a shortage of donor hearts in Switzerland, especially for pediatric recipients. However, the rate and reason for refusals of pediatric donor hearts offered in Switzerland has not been systematically analyzed.

METHODS

The national transplant database, Swiss Organ Allocation System, was searched for all hearts from Swiss and foreign donors younger than 16 years from 2015 to 2020. The numbers of accepted and refused hearts and early outcome were assessed, and the reasons for refusal were retrospectively analyzed.

RESULTS

A total of 136 organs were offered to the three Swiss pediatric heart centers and foreign donor procurement organizations. Of these, 26/136 (19%) organs were accepted and transplanted: 18 hearts were transplanted in Switzerland, and 13 of these were foreign. Reasons for refusal were (1) no compatible recipient due to blood group or weight mismatch, 89.4%; (2) medical, meaning organ too marginal for transplantation, 7.4%; (3) logistic, 1.4%; and (4) other, 1.8%. Five organs were refused in Switzerland by one center but later accepted and successfully transplanted by another center. Hearts from outside Switzerland were transplanted significantly less than Swiss hearts (n = 16/120 vs. 10/16, p < .001).

CONCLUSION

The most common reason for refusing a pediatric donor heart is lack of compatibility with the recipient. Few hearts are refused for medical reasons. A more generous acceptance seems to be justified in selected patients. Switzerland receives a high number of foreign offers, but their rate of acceptance is lower than that of Swiss donations.

Cardiac magnetic resonance in advanced heart failure

Heart failure (HF) is a chronic and progressive disease that often progresses to an advanced stage where conventional therapy is insufficient to relieve patients' symptoms. Despite the availability of advanced therapies such as mechanical circulatory support or heart transplantation, the complexity of defining advanced HF, which requires multiple parameters and multimodality assessment, often leads to delays in referral to dedicated specialists with the result of a worsening prognosis. In this review, we aim to explore the role of cardiac magnetic resonance (CMR) in advanced HF by showing how CMR is useful at every step in managing these patients: from diagnosis to prognostic stratification, hemodynamic evaluation, follow-up and advanced therapies such as heart transplantation. The technical challenges of scanning advanced HF patients, which often require troubleshooting of intracardiac devices and dedicated scans, will be also discussed.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Outcome-based Risk Assessment of Non-HLA Antibodies in Heart Transplantation: A Systematic Review

BACKGROUND

Current monitoring after heart transplantation (HT) employs repeated invasive endomyocardial biopsies (EMB). Although positive EMB confirms rejection, EMB fails to predict impending, subclinical, or EMB-negative rejection events. While non-human leukocyte antigen (non-HLA) antibodies have emerged as important risk factors for antibody-mediated rejection after HT, their use in clinical risk stratification has been limited. A systematic review of the role of non-HLA antibodies in rejection pathologies has the potential to guide efforts to overcome deficiencies of EMB in rejection monitoring.

METHODS

Databases were searched to include studies on non-HLA antibodies in HT recipients. Data collected included the number of patients, type of rejection, non-HLA antigen studied, association of non-HLA antibodies with rejection, and evidence for synergistic interaction between non-HLA antibodies and donor-specific anti-human leukocyte antigen antibody (HLA-DSA) responses.

RESULTS

A total of 56 studies met the inclusion criteria. Strength of evidence for each non-HLA antibody was evaluated based on the number of articles and patients in support versus against their role in mediating rejection. Importantly, despite previous intense focus on the role of anti-major histocompatibility complex class I chain-related gene A (MICA) and anti-angiotensin II type I receptor antibodies (AT1R) in HT rejection, evidence for their involvement was equivocal. Conversely, the strength of evidence for other non-HLA antibodies supports that differing rejection pathologies are driven by differing non-HLA antibodies.

CONCLUSIONS

This systematic review underscores the importance of identifying peri-HT non-HLA antibodies. Current evidence supports the role of non-HLA antibodies in all forms of HT rejection. Further investigations are required to define the mechanisms of action of non-HLA antibodies in HT rejection.

The value of extracorporeal photopheresis as an immunosuppression-modifying approach in solid organ transplantation: a potential solution to an unmet medical need

Allograft rejection is a critical issue following solid organ transplantation (SOT). Immunosuppressive therapies are crucial in reducing risk of rejection yet are accompanied by several significant side effects, including infection, malignancy, cardiovascular diseases, and nephrotoxicity. There is a current unmet medical need with a lack of effective minimization strategies for these side effects. Extracorporeal photopheresis (ECP) has shown potential as an immunosuppression (IS)-modifying technique in several SOT types, with improvements seen in acute and recurrent rejection, allograft survival, and associated side effects, and could fulfil this unmet need. Through a review of the available literature detailing key areas in which ECP may benefit patients, this review highlights the IS-modifying potential of ECP in the four most common SOT procedures (heart, lung, kidney, and liver transplantation) and highlights existing gaps in data. Current evidence supports the use of ECP for IS modification following SOT, however there is a need for further high-quality research, in particular randomized control trials, in this area.

Increase of Cardiac Autoantibodies Against Beta-2-adrenergic Receptor During Acute Cellular Heart Transplant Rejection

BACKGROUND

Acute cellular rejection (ACR) in heart transplant (HTx) recipients may be accompanied by cardiac cell damage with subsequent exposure to cardiac autoantigens and the production of cardiac autoantibodies (aABs). This study aimed to evaluate a peptide array screening approach for cardiac aABs in HTx recipients during ACR (ACR-HTx).

METHODS

In this retrospective single-center observational study, sera from 37 HTx recipients, as well as age and sex-matched healthy subjects were screened for a total of 130 cardiac aABs of partially overlapping peptide sequences directed against structural proteins using a peptide array approach.

RESULTS

In ACR-HTx, troponin I (TnI) serum levels were found to be elevated. Here, we could identify aABs against beta-2-adrenergic receptor (β-2AR: EAINCYANETCCDFFTNQAY) to be upregulated in ACR-HTx (intensities: 0.80 versus 1.31, P = 0.0413). Likewise, patients positive for β-2AR aABs showed higher TnI serum levels during ACR compared with aAB negative patients (10.0 versus 30.0 ng/L, P = 0.0375). Surprisingly, aABs against a sequence of troponin I (TnI: QKIFDLRGKFKRPTLRRV) were found to be downregulated in ACR-HTx (intensities: 3.49 versus 1.13, P = 0.0025). A comparison in healthy subjects showed the same TnI sequence to be upregulated in non-ACR-HTx (intensities: 2.19 versus 3.49, P = 0.0205), whereas the majority of aABs were suppressed in non-ACR-HTx.

CONCLUSIONS

Our study served as a feasibility analysis for a peptide array screening approach in HTx recipients during ACR and identified 2 different regulated aABs in ACR-HTx. Hence, further multicenter studies are needed to evaluate the prognostic implications of aAB testing and diagnostic or therapeutic consequences.

Tacrolimus-loaded Drug Delivery Systems in Vascularized Composite Allotransplantation: Lessons and Opportunities for Local Immunosuppression

Long-term systemic immunosuppression is needed for vascularized composite allotransplantation (VCA). The high rate of acute rejection episodes in the first posttransplant year, the development of chronic rejection, and the adverse effects that come along with this treatment, currently prevent a wider clinical application of VCA. Opportunistic infections and metabolic disturbances are among the most observed side effects in VCA recipients. To overcome these challenges, local immunosuppression using biomaterial-based drug delivery systems (DDS) have been developed. The aim of these systems is to provide high local concentrations of immunosuppressive drugs while reducing their systemic load. This review provides a summary of recently investigated local DDS with different mechanisms of action such as on-demand, ultrasound-sensitive, or continuous drug delivery. In preclinical models, ranging from rodent to porcine and nonhuman primate models, this approach has been shown to reduce systemic tacrolimus (TAC) load and adverse effects, while prolonging graft survival. Localized immunosuppression using biomaterial-based DDS represents an encouraging approach to enhance graft survival and reduce toxic side effects of immunosuppressive drugs in VCA patients. Preclinical models using TAC-releasing DDS have demonstrated high local immunosuppressive effects with a low systemic burden. However, to reduce acute rejection events in translational animal models or in the clinical reality, the use of additional low-dose systemic TAC treatment may be envisaged. Patients may benefit through efficient graft immunosuppression and survival with negligible systemic adverse effects, resulting in better compliance and quality of life.

Induction therapy in heart transplantation: A systematic review and network meta-analysis for developing evidence-based recommendations

INTRODUCTION

Induction therapy (IT) utility in heart transplantation (HT) remains contested. Commissioned by a clinical-practice guidelines panel to evaluate the effectiveness and safety of IT in adult HT patients, we conducted this systematic review and network meta-analysis (NMA).

METHODS

We searched for studies from January 2000 to October 2022, reporting on the use of any IT agent in adult HT patients. Based on patient-important outcomes, we performed frequentist NMAs separately for RCTs and observational studies with adjusted analyses, and assessed the certainty of evidence using the GRADE framework.

RESULTS

From 5156 publications identified, we included 7 RCTs and 12 observational studies, and report on two contemporarily-used IT agents-basiliximab and rATG. The RCTs provide only very low certainty evidence and was uninformative of the effect of the two agents versus no IT or one another. With low certainty in the evidence from observational studies, basiliximab may increase 30-day (OR 1.13; 95% CI 1.06-1.20) and 1-year (OR 1.11; 95% CI 1.02-1.22) mortality compared to no IT. With low certainty from observational studies, rATG may decrease 5-year cardiac allograft vasculopathy (OR .82; 95% CI .74-.90) compared to no IT, as well as 30-day (OR .85; 95% CI .80-.92), 1-year (OR .87; 95% CI .79-.96), and overall (HR .84; 95% CI .76-.93) mortality compared to basiliximab.

CONCLUSION

With low and very low certainty in the synthetized evidence, these NMAs suggest possible superiority of rATG compared to basiliximab, but do not provide compelling evidence for the routine use of these agents in HT recipients.

Unique 40-year survival after heart transplantation with normal graft function and spontaneous operational tolerance

Unique 40-year survival after heart transplantation with normal graft function and spontaneous operational tolerance.

Transthoracic echocardiography is a simple tool for size matching in cardiac xenotransplantation

BACKGROUND

Preoperative size matching is essential for both allogeneic and xenogeneic heart transplantation. In preclinical pig-to-baboon xenotransplantation experiments, porcine donor organs are usually matched to recipients by using indirect parameters, such as age and total body weight. For clinical use of xenotransplantation, a more precise method of size measurement would be desirable to guarantee a "perfect match." Here, we investigated the use of transthoracic echocardiography (TTE) and described a new method to estimate organ size prior to xenotransplantation.

METHODS

Hearts from n = 17 genetically modified piglets were analyzed by TTE and total heart weight (THW) was measured prior to xenotransplantation into baboons between March 2018 and April 2022. Left ventricular (LV) mass was calculated according to the previously published method by Devereux et al. and a newly adapted formula. Hearts from n = 5 sibling piglets served as controls for the determination of relative LV and right ventricular (RV) mass. After explantation, THW and LV and RV mass were measured.

RESULTS

THW correlated significantly with donor age and total body weight. The strongest correlation was found between THW and LV mass calculated by TTE. Compared to necropsy data of the control piglets, the Devereux formula underestimated both absolute and relative LV mass, whereas the adapted formula yielded better results. Combining the adapted formula and the relative LV mass data, THW can be predicted with TTE.

CONCLUSIONS

We demonstrate reliable LV mass estimation by TTE for size matching prior to xenotransplantation. An adapted formula provides more accurate results of LV mass estimation than the generally used Devereux formula in the xenotransplantation setting. TTE measurement of LV mass is superior for the prediction of porcine heart sizes compared to conventional parameters such as age and total body weight.

Cardiac transplant rejection assessment with 18F-FDG PET-CT: initial single-centre experience for diagnosis and management

BACKGROUND

Rejection is a major cause of mortality and morbidity in heart transplant (HTx) recipients. Current methods for diagnosing rejection have limitations. Imaging methods to map the entire left ventricle and reliably identify potential sites of rejection is lacking. Animal studies suggest FDG PET-CT (FDG PET) could have potential application in human HTx recipients.

METHODS

Between December 2020 and February 2022, all HTx recipients at Harefield Hospital, London, with definite or suspected rejection underwent FDG PET in addition to routine work-up.

RESULTS

Thirty HTx recipients (12 with definite and 18 with suspected rejection) underwent FDG PET scans. Overall, 12 of the 30 patients had FDG PET with increased myocardial avidity, of whom 2 died (17%). Eighteen patients of the 30 patients had FDG PET with no myocardial avidity and all are alive (100%, p = 0.15). All patients with definite rejection, scanned within 2 weeks of starting anti-rejection treatment, showed increased myocardial avidity. In 5 cases, FDG PET showed myocardial avidity beyond 6 weeks despite pulsed steroid treatment, suggesting unresolved myocardial rejection.

CONCLUSION

Preliminary findings suggest FDG PET may have a role in diagnosing cardiac transplant rejection. Future blinded studies are needed to help further validate this.

Employment Status Following Heart Transplantation: Data From the Danish Nationwide Social Service Payment Register During 20 years

Most studies on vocational rehabilitation after heart transplantation (HTX) are based on self-reported data. Danish registries include weekly longitudinal information on all public transfer payments. We intended to describe 20-year trends in employment status for the Danish heart-transplant recipients, and examine the influence of multimorbidity and socioeconomic position (SEP). Linking registry and Scandiatransplant data (1994-2018), we conducted a study in recipients of working age (19-63 years). The cohort contained 492 recipients (79% males) and the median (IQR) age was 52 years (43-57 years). Five years after HTX, 30% of the survived recipients participated on the labor market; 9% were in a flexible job with reduced health-related working capacity. Moreover, 60% were retired and 10% eligible for labor market participation were unemployed. Recipients with multimorbidity had a higher age and a lower prevalence of employment. Five years after HTX, characteristics of recipients with labor market participation were: living alone (27%) versus cohabitation (73%); low (36%) versus medium-high (64%) educational level; low (13%) or medium-high (87%) income group. Heart-transplant recipients with multimorbidity have a higher age and a lower prevalence of employment. Socioeconomically disadvantaged recipients had a lower prevalence of labor market participation, despite being younger compared with the socioeconomically advantaged.

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

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

Ten-Year Experience with Endomyocardial Biopsy after Orthotopic Heart Transplantation: Comparison between Trans-Jugular and Trans-Femoral Approach

BACKGROUND

Endomyocardial biopsy (EMB) is considered the gold standard for monitoring allograft rejection after heart transplantation. EMB is an invasive procedure that may be performed via a trans-jugular or a trans-femoral approach with a complication rate reported as less than 6%. The aim of this study was to evaluate the complication rate after EMBs in heart recipients and to compare the results of EMBs performed via a trans-jugular or a trans-femoral approach.

METHODS

Medical records of heart recipients undergoing EMBs between January 2012 and December 2022 were retrospectively reviewed. EMB-related complications were classified as major (death, pericardial effusion, hemopericardium, cardiac tamponade requiring a pericardiocentesis or an urgent cardiac surgery, ventricular arrythmias, permanent atrio-ventricular block requiring permanent pacing, hemothorax, pneumothorax and retroperitoneal bleeding) and minor (de novo tricuspid regurgitation, arrhythmias, coronary artery fistula, vascular access site complications).

RESULTS

A total of 1698 EMBs were performed during the study period at our institution in 212 heart recipients. There were 927 (55%) EMBs performed through a trans-jugular approach (TJ group) and 771 (45%) EMBs performed through a trans-femoral approach (TF group). A total of 60 (3.5%) complications were recorded, including nine (0.5%) major complications (six cardiac tamponades, two pneumothorax and one retroperitoneal bleeding) and 51 (3%) minor complications (seven coronary fistulae, five de novo tricuspid regurgitation, four supraventricular arrythmias and thirty-five vascular access site complications). No difference was found in total (38 [4%] vs. 22 [3%]; p = 0.16) and major (6 [1%} vs. 3 [0.4%]; p = 0.65) complications (32 [3%] vs. 19 [2%]; p = 0.23) between the TJ group and the TF group. No difference was found in male sex, age at time of EMB and time from HT between complicated and not complicated EMBs.

CONCLUSIONS

EMBs represent a safe procedure with a low risk of complications. In our experience, EMBs performed via a trans-jugular approach are as safe as the trans-femoral approach.

Adults with Congenital Heart Disease and Transplant: Challenges, Opportunities, and Policy

The rate of heart transplantation in adults with congenital heart disease (ACHD) is rising, but the 1-year mortality posttransplantation remains higher than non-ACHD patients. A robust pretransplant assessment and operative and postoperative planning can mitigate much of the perioperative risk. Importantly, ACHD patients who survive the first year have significantly better 10-year survival compared with non-ACHD patients. The current allocation system gives ACHD patients a relatively high priority, but providers must use the prespecified exception requests for higher status, especially for patients with the Fontan circulation. It is vital that ACHD patients with end-stage heart failure are cared for at centers with ACHD subspecialty care.

Use of intraoperative haemoadsorption in patients undergoing heart transplantation: a proof-of-concept randomized trial

AIMS

The aim of this trial was to compare the clinical effects of intraoperative haemoadsorption versus standard care in patients undergoing orthotopic heart transplantation (OHT).

METHODS AND RESULTS

In a randomized, controlled trial, OHT recipients were randomized to receive intraoperative haemoadsorption or standard care. Outcomes were vasoactive-inotropic score (VIS), frequency of vasoplegic syndrome (VS) in the first 24 h; post-operative change in procalcitonin (PCT) and C-reactive protein (CRP) levels; intraoperative change in mycophenolic acid (MPA) concentration; frequency of post-operative organ dysfunction, major complications, adverse immunological events and length of in-hospital stay and 1-year survival. Sixty patients were randomized (haemoadsorption group N = 30, control group N = 25 plus 5 exclusions). Patients in the haemoadsorption group had a lower median VIS and rate of VS (VIS: 27.2 [14.6-47.7] vs. 41.9 [22.4-63.2], P = 0.046, and VS: 20.0% vs. 48.0%, P = 0.028, respectively), a 6.4-fold decrease in the odds of early VS (OR: 0.156, CI: 0.029-0.830, P = 0.029), lower PCT levels, shorter median mechanical ventilation (MV: 25 [19-68.8] hours vs. 65 [23-287] hours, P = 0.025, respectively) and intensive care unit stay (ICU stay: 8.5 [8.0-10.3] days vs. 12 [8.5-18.0] days, P = 0.022, respectively) than patients in the control group. Patients in the haemoadsorption versus control group experienced lower rates of acute kidney injury (AKI: 36.7% vs. 76.0%, P = 0.004, respectively), renal replacement therapy (RRT: 0% vs. 16.0%, P = 0.037, respectively) and lower median per cent change in bilirubin level (PCB: 2.5 [-24.6 to 71.1] % vs. 72.1 [11.2-191.4] %, P = 0.009, respectively) during the post-operative period. MPA concentrations measured at pre-defined time points were comparable in the haemoadsorption compared to control groups (MPA pre-cardiopulmonary bypass: 2.4 [1.15-3.60] μg/mL vs. 1.6 [1.20-3.20] μg/mL, P = 0.780, and MPA 120 min after cardiopulmonary bypass start: 1.1 [0.58-2.32] μg/mL vs. 0.9 [0.45-2.10] μg/mL, P = 0.786). The rates of cardiac allograft rejection, 30-day mortality and 1-year survival were similar between the groups.

CONCLUSIONS

Intraoperative haemoadsorption was associated with better haemodynamic stability, mitigated PCT response, lower rates of post-operative AKI and RRT, more stable hepatic bilirubin excretion, and shorter durations of MV and ICU stay. Intraoperative haemoadsorption did not show any relevant adsorption effect on MPA. There was no increase in the frequency of early cardiac allograft rejection related to intraoperative haemoadsorption use.

Report of the 2022 Banff Heart Concurrent: Focus on non-human leukocyte antigen antibodies in rejection and the pathology of "mixed" rejection

The Banff Heart Concurrent Session, held as part of the 16th Banff Foundation for Allograft Pathology Conference at Banff, Alberta, Canada, on September 21, 2022, focused on 2 major topics: non-human leukocyte antigen (HLA) antibodies and mixed rejection. Each topic was addressed in a multidisciplinary fashion with clinical, immunological, and pathology perspectives and future developments and prospectives. Following the Banff organization model and principles, the collective aim of the speakers on each topic was to • Determine current knowledge gaps in heart transplant pathology • Identify limitations of current pathology classification systems • Discuss next steps in addressing gaps and refining classification system.

Protein Phosphatase 2A Activation Promotes Heart Transplant Acceptance in Mice

BACKGROUND

Although heart transplantation is the definitive treatment for heart failure in eligible patients, both acute and chronic transplant rejection frequently occur. Protein phosphatase 2A (PP2A) activity is critical in maintaining tissue and organ homeostasis. In this study, we evaluated the effect of a novel class of small molecule activators of PP2A (SMAPs) on allograft rejection in a mouse heterotopic heart transplantation model.

METHODS

Recipient mice were administered with DT-061 (a pharmaceutically optimized SMAP) or vehicle by oral gavage beginning 1 d after transplantation. Histological and immunofluorescence analyses were performed to examine allograft rejection. Regulatory T cells (Treg) from recipient spleens were subjected to flow cytometry and RNA sequencing analysis. Finally, the effect of DT-061 on smooth muscle cells (SMCs) migration and proliferation was assessed.

RESULTS

DT-061 treatment prolonged cardiac allograft survival. SMAPs effectively suppressed the inflammatory immune response while increasing Treg population in the allografts, findings corroborated by functional analysis of RNA sequencing data derived from Treg of treated splenic tissues. Importantly, SMAPs extended immunosuppressive agent cytotoxic T lymphocyte-associated antigen-4-Ig-induced cardiac transplantation tolerance and allograft survival. SMAPs also strongly mitigated cardiac allograft vasculopathy as evidenced by a marked reduction of neointimal hyperplasia and SMC proliferation. Finally, our in vitro studies implicate suppression of MEK/ERK pathways as a unifying mechanism for the effect of PP2A modulation in Treg and SMCs.

CONCLUSIONS

PP2A activation prevents cardiac rejection and prolongs allograft survival in a murine model. Our findings highlight the potential of PP2A activation in improving alloengraftment in heart transplantation.

Acetylsalicylic acid use and development of cardiac allograft vasculopathy: A national prospective study using highly automated 3-D optical coherence tomography analysis

BACKGROUND

There is conflicting evidence on the role of acetylsalicylic acid (ASA) use in the development of cardiac allograft vasculopathy (CAV).

METHODS

A nationwide prospective two-center study investigated changes in the coronary artery vasculature by highly automated 3-D optical coherence tomography (OCT) analysis at 1 month and 12 months after heart transplant (HTx). The influence of ASA use on coronary artery microvascular changes was analyzed in the overall study cohort and after propensity score matching for selected clinical CAV risk factors.

RESULTS

In total, 175 patients (mean age 52 ± 12 years, 79% male) were recruited. During the 1-year follow-up, both intimal and media thickness progressed, with ASA having no effect on its progression. However, detailed OCT analysis revealed that ASA use was associated with a lower increase in lipid plaque (LP) burden (p = .013), while it did not affect the other observed pathologies. Propensity score matching of 120 patients (60 patient pairs) showed similar results, with ASA use associated with lower progression of LPs (p = .002), while having no impact on layered fibrotic plaque (p = .224), calcification (p = .231), macrophage infiltration (p = .197), or the absolute coronary artery risk score (p = .277). According to Kaplan-Meier analysis, ASA use was not associated with a significant difference in survival (p = .699) CONCLUSION: This study showed a benefit of early ASA use after HTx on LP progression. However, ASA use did not have any impact on the progression of other OCT-observed pathologies or long-term survival.

Use of induction therapy post-heart transplantation: Clinical practice recommendations based on systematic review and network meta-analysis of evidence

BACKGROUND

The use of induction therapy (IT) agents in the early post-heart transplant period remains controversial. The following recommendations aim to provide guidance on the use of IT agents, including Basiliximab and Thymoglobulin, as part of routine care in heart transplantation (HTx).

METHODS

We recruited an international, multidisciplinary panel of 15 stakeholders, including patient partners, transplant cardiologists and surgeons, nurse practitioners, pharmacists, and methodologists. We commissioned a systematic review on benefits and harms of IT on patient-important outcomes, and another on patients' values and preferences to inform our recommendations. We used the GRADE framework to summarize our findings, rate certainty in the evidence, and develop recommendations. The panel considered the balance between benefits and harms, certainty in the evidence, and patient's values and preferences, to make recommendations for or against the routine post-operative use of Thymoglobulin or Basiliximab.

RESULTS

The panel made recommendations on three major clinical problems in HTx: (1) We suggest against the routine post-operative use of Basiliximab compared to no IT, (2) we suggest against the routine use of Thymoglobulin compared to no IT, and (3) for those patients for whom IT is deemed desirable, we suggest for the use of Thymoglobulin as compared to Basiliximab.

CONCLUSION

This report highlights gaps in current knowledge and provides directions for clinical research in the future to better understand the clinical utility of IT agents in the early post heart transplant period, leading to improved management and care.

Improved Graft Function following Desensitization of Anti-AT1R and Autoantibodies in a Heart Transplant Recipient Negative for Donor-Specific Antibodies with Antibody-Mediated Rejection: A Case Report

HLA donor-specific antibodies (DSAs) pre and post transplant increase the risk of antibody-mediated rejection (AMR) and lead to poor graft survival. Increasing data exist to support the involvement of non-HLA antibodies in triggering an immunological response. The development of non-HLA antibodies specific for AT1R is associated with poor clinical outcomes in orthotopic heart transplant recipients. This case presents an investigation of non-HLA antibodies in a 56-year-old female heart transplant recipient diagnosed with AMR in the absence of DSAs.

Enhancing the Prediction of Cardiac Allograft Vasculopathy Using Intravascular Ultrasound and Machine Learning: A Proof of Concept

BACKGROUND

Cardiac allograft vasculopathy (CAV) is the leading cause of late graft dysfunction in heart transplantation. Building on previous unsupervised learning models, we sought to identify CAV clusters using serial maximal intimal thickness and baseline clinical risk factors to predict the development of early CAV.

METHODS

This is a single-center retrospective study including adult heart transplantation recipients. A latent class mixed-effects model was used to identify patient clusters with similar trajectories of maximal intimal thickness posttransplant and pretransplant covariates associated with each cluster.

RESULTS

Among 186 heart transplantation recipients, we identified 4 patient phenotypes: very low, low, moderate, and high risk. The 5-year risk (95% CI) of the International Society for Heart and Lung Transplantation-defined CAV in the high, moderate, low, and very low risk groups was 49.1% (35.2%-68.5%), 23.4% (13.3%-41.2%), 5.0% (1.3%-19.6%), and 0%, respectively. Only patients in the moderate to high risk cluster developed the International Society for Heart and Lung Transplantation CAV 2-3 at 5 years (P=0.02). Of the 4 groups, the low risk group had significantly younger female recipients, shorter ischemic time, and younger female donors compared with the high risk group.

CONCLUSIONS

We identified 4 clusters characterized by distinct maximal intimal thickness trajectories. These clusters were shown to discriminate against the development of angiographic CAV. This approach allows for the personalization of surveillance and CAV-directed treatment before the development of angiographically apparent disease.

Infections in the first year after heart transplantation in a Latin American country

BACKGROUND

Heart transplantation is the therapy of choice in patients with advanced heart failure refractory to other medical or surgical management. However, heart transplants are associated with complications that increase posttransplant morbidity and mortality. Infections are one of the most important complications after this procedure. Therefore, infections in the first year after heart transplantation were evaluated.

METHODS

A retrospective cohort study of infections after heart transplants was conducted in a teaching hospital in Colombia between 2011 and 2019. Patients registered in the institutional heart transplant database (RETRAC) were included in the study. Microbiological isolates and infectious serological data were matched with the identities of heart transplant recipients and data from clinical records of individuals registered in the RETRAC were analyzed. The cumulative incidences of events according to the type of microorganism isolated were estimated using Kaplan-Meier survival analyses.

RESULTS

Seventy-nine patients were included in the study. Median age was 49 years (37.4-56.3), and 26.58% of patients were women. Eighty-seven infections were documented, of which 55.17% (48) were bacterial, 22.99% (20) were viral, and 12.64% (11) were fungal. Bacterial infections predominated in the first month. In the first year, infections caused 38.96% of hospital admissions and were the second cause of death after heart transplants (25.0%).

CONCLUSION

Posttransplant infections in the first year of follow-up were frequent. Bacterial infections predominated in the early posttransplant period. Infections, mainly bacterial, were the second most common cause of death and the most common cause of hospitalization in the first year after heart transplantation.

Failing to Make the Grade: Conventional Cardiac Allograft Rejection Grading Criteria Are Inadequate for Predicting Rejection Severity

BACKGROUND

Cardiac allograft rejection is the leading cause of early graft failure and is a major focus of postheart transplant patient care. While histological grading of endomyocardial biopsy samples remains the diagnostic standard for acute rejection, this standard has limited diagnostic accuracy. Discordance between biopsy rejection grade and patient clinical trajectory frequently leads to both overtreatment of indolent processes and delayed treatment of aggressive ones, spurring the need to investigate the adequacy of the current histological criteria for assessing clinically important rejection outcomes.

METHODS

N=2900 endomyocardial biopsy images were assigned a rejection grade label (high versus low grade) and a clinical trajectory label (evident versus silent rejection). Using an image analysis approach, n=370 quantitative morphology features describing the lymphocytes and stroma were extracted from each slide. Two models were constructed to compare the subset of features associated with rejection grades versus those associated with clinical trajectories. A proof-of-principle machine learning pipeline-the cardiac allograft rejection evaluator-was then developed to test the feasibility of identifying the clinical severity of a rejection event.

RESULTS

The histopathologic findings associated with conventional rejection grades differ substantially from those associated with clinically evident allograft injury. Quantitative assessment of a small set of well-defined morphological features can be leveraged to more accurately reflect the severity of rejection compared with that achieved by the International Society of Heart and Lung Transplantation grades.

CONCLUSIONS

Conventional endomyocardial samples contain morphological information that enables accurate identification of clinically evident rejection events, and this information is incompletely captured by the current, guideline-endorsed, rejection grading criteria.

Pharmacotherapy in the heart transplant recipient: A primer for nurse clinicians and pharmacists

Heart transplantation (HT) is the definitive treatment for eligible patients with end-stage heart disease. A major complication of HT is allograft rejection which can lead to graft dysfunction and death. The guiding principle of chronic immunosuppression therapy is to prevent rejection of the transplanted organ while avoiding oversuppression of the immune system, which can cause opportunistic infections and malignancy. The purpose of this review is to describe immunosuppressive management of the HT recipient-including agent-specific pharmacology and pharmacokinetics, outcomes data, adverse effects, clinical considerations, and recent guideline updates. We will also provide recommendations for medical prophylaxis of immunosuppressed patients based on the most recent clinical guidelines. Additionally, we highlight the importance of medical therapy adherence and the effect of social determinants of health on the long-term management of HT. HT recipients are a complex and high-risk population. The objective of this review is to describe basic pharmacotherapy in HT and implications for nurses and pharmacists.

Feasibility of Interleukin-6 Receptor Blockade in Cardiac Antibody-mediated Rejection

BACKGROUND

Antibody-mediated rejection (AMR) remains a significant cause of heart transplant mortality with few effective therapies.

METHODS

This study aimed to describe initial experience of using interleukin-6 receptor blockade with tocilizumab in the treatment of acute cardiac AMR at Barnes-Jewish Hospital/Washington University Transplant Center from July 2017 to May 2021 (n = 7). Clinical, echocardiographic, and serum alloantibody data were analyzed before and after treatment.

RESULTS

All participants demonstrated marked improvement in functional status. Echocardiographic data following 4-6 mo of tocilizumab revealed significant improvements in biventricular systolic function for all participants. Consistent reductions in donor-specific HLA or angiotensin type I receptor antibodies were not observed, suggesting that tocilizumab may act downstream of antibody production. No patient experienced drug-related complications that necessitated discontinuation of therapy.

CONCLUSIONS

These findings provide initial insights into the safety and efficacy of interleukin-6 receptor blockade in the treatment of cardiac AMR and support the design of larger prospective studies.

Implementation of a Synergistic, Complementary Pharmacy Practice Model for an Advanced Heart Failure/Heart Transplant Program

Study Objective: A pharmacy practice model for an Advanced Heart Failure (HF)/Transplant program was designed to address gaps in medication access, medication education and transitions of care (ToC). Activities specific to these initiatives performed by a four-member pharmacy team (3 pharmacists, 1 specialty technician) are described. Methods: Data were prospectively collected in 2020 for 284 admissions involving a high-risk cohort of advanced HF/transplant patients and a similar cohort seen in an ambulatory HF clinic. Interventions including medication reconciliation, e-prescribing, patient consultation and telephone call backs were performed daily to ensure medication access on discharge and as outpatients, comprehensive medication education on a continuum, and improved ToC. Metrics specific to these interventions and revenue reflecting outpatient prescription volume were quantified. Results: Standardized discharge medication education was provided to 97% of the cohort (n = 275). Of the 51 patients newly transplanted or receiving a left ventricular assist device, 100% had medication access on discharge and received follow-up telephone consultation within 48 hours. ToC was performed on admission (97%), pre-operatively (n = 51; 100%), post-operatively (n = 51; 100%) and on discharge (97%). Outpatient prescription volume increased 42% with net revenue increasing 157%. Conclusion: A pharmacy practice model involving an integrated 4-member team improved medication access and education and allowed for ToC at multiple points in the care process thereby improving medication safety. Collaboration between pharmacists and technicians working in inpatient, outpatient and specialty pharmacy settings is encouraged to provide complementary care to high-risk patients.

Quantitative flow ratio computed from invasive coronary angiography as a predictor for cardiac allograft vasculopathy after cardiac transplant

Cardiac allograft vasculopathy (CAV) is a significant determinant of long-term survival in heart transplant recipients. Standard CAV screening typically utilizes invasive coronary angiography (ICA). Quantitative flow ratio (QFR) is a computational method for functional testing of coronary stenosis, and may add diagnostic value to ICA in assessing CAV. Consecutive subjects who received heart transplantation and underwent two separate routine coronary angiograms between January 2013 and April 2016 were enrolled. Coronary angiograms and IVUS were performed per local protocol at 1, 2, 3 and 5 years post-transplant. QFR was calculated offline. CAV was assessed semi-quantitively based on coronary angiogram results. Twenty-two patients were enrolled. Mean time from transplant to first included ICA was 2.1 years. QFR in at least 1 coronary vessel was interpretable in 19/22 (86%) of initial ICA (QFR1). QFR1 correlated well with the CAV score derived from the second ICA (CAV2) with a clustering of CAV at lower QFR values. In a receiver-operating characteristic (ROC) analysis, an optimal QFR threshold of 0.88 yielded 0.94 sensitivity and 0.67 specificity (AUC of 0.79) for at least non-obstructive subsequent CAV. Initial angiographically and intravascular ultrasound derived CAV severity poorly predicted subsequent CAV severity. QFR derived from invasive coronary angiography predicts subsequent development of CAV more accurately than angiography and intravascular ultrasound. This novel method of coronary flow assessment in recipients of heart transplantation may be useful to diagnose and predict subsequent CAV development.

The clinical use of stress echocardiography in chronic coronary syndromes and beyond coronary artery disease: a clinical consensus statement from the European Association of Cardiovascular Imaging of the ESC

Since the 2009 publication of the stress echocardiography expert consensus of the European Association of Echocardiography, and after the 2016 advice of the American Society of Echocardiography-European Association of Cardiovascular Imaging for applications beyond coronary artery disease, new information has become available regarding stress echo. Until recently, the assessment of regional wall motion abnormality was the only universally practiced step of stress echo. In the state-of-the-art ABCDE protocol, regional wall motion abnormality remains the main step A, but at the same time, regional perfusion using ultrasound-contrast agents may be assessed. Diastolic function and pulmonary B-lines are assessed in step B; left ventricular contractile and preload reserve with volumetric echocardiography in step C; Doppler-based coronary flow velocity reserve in the left anterior descending coronary artery in step D; and ECG-based heart rate reserve in non-imaging step E. These five biomarkers converge, conceptually and methodologically, in the ABCDE protocol allowing comprehensive risk stratification of the vulnerable patient with chronic coronary syndromes. The present document summarizes current practice guidelines recommendations and training requirements and harmonizes the clinical guidelines of the European Society of Cardiology in many diverse cardiac conditions, from chronic coronary syndromes to valvular heart disease. The continuous refinement of imaging technology and the diffusion of ultrasound-contrast agents improve image quality, feasibility, and reader accuracy in assessing wall motion and perfusion, left ventricular volumes, and coronary flow velocity. Carotid imaging detects pre-obstructive atherosclerosis and improves risk prediction similarly to coronary atherosclerosis. The revolutionary impact of artificial intelligence on echocardiographic image acquisition and analysis makes stress echo more operator-independent and objective. Stress echo has unique features of low cost, versatility, and universal availability. It does not need ionizing radiation exposure and has near-zero carbon dioxide emissions. Stress echo is a convenient and sustainable choice for functional testing within and beyond coronary artery disease.

Heart Transplantation

Heart transplantation (HTx) remains the last therapeutic resort for patients with advanced heart failure. The present work is a clinically focused review discussing current issues in heart transplantation. Several factors have been associated with the outcome of HTx, such as ABO and HLA compatibility, graft size, ischemic time, age, infections, and the cause of death, as well as imaging and laboratory tests. In 2018, UNOS changed the organ allocation policy for HTx. The aim of this change was to prioritize patients with a more severe clinical condition resulting in a reduction in mortality of people on the waiting list. Advanced heart failure and resistant angina are among the main indications of HTx, whereas active infection, peripheral vascular disease, malignancies, and increased body mass index (BMI) are important contraindications. The main complications of HTx include graft rejection, graft angiopathy, primary graft failure, infection, neoplasms, and retransplantation. Recent advances in the field of HTx include the first two porcine-to-human xenotransplantations, the inclusion of hepatitis C donors, donation after circulatory death, novel monitoring for acute cellular rejection and antibody-mediated rejection, and advances in donor heart preservation and transportation. Lastly, novel immunosuppression therapies such as daratumumab, belatacept, IL 6 directed therapy, and IgG endopeptidase have shown promising results.

Safety and efficacy of everolimus-eluting bioresorbable vascular scaffold for cardiac allograft vasculopathy (CART)

BACKGROUND

Cardiac allograft vasculopathy (CAV) is still the main drawback of heart transplantation (HTx) and percutaneous coronary intervention (PCI) is a palliative measure because of the high incidence of failure.

OBJECTIVE

This study aimed to investigate the safety and efficacy of bioresorbable scaffolds (BRSs) as potential novel therapeutic tool for the treatment of coronary stenoses in CAV.

METHODS

This is a multicenter, single-arm, prospective, open-label study (CART, NCT02377648), that included patients affected by advanced CAV treated with PCI and second-generation ABSORB BRS (Abbott Vascular). The primary endpoint was the incidence of 12-month angiographic in-segment scaffold restenosis (ISSR). Secondary endpoints were the incidence of major adverse cardiac events (MACEs) at 12- and 36-month follow-up and the incidence of ISSR at 36 months. A paired intracoronary imaging analysis at baseline and follow-up was also performed.

RESULTS

Between 2015 and 2017 35 HTx patients were enrolled and treated for 44 coronary lesions with 51 BRSs. The primary endpoint occurred in 13.5% of the lesions (5/37), with a cumulative ISSR rate up to 3 years of 16.2% (6/37). Angiographic lumen loss was 0.40 ± 0.62 mm at 12 months and 0.53 ± 0.57 mm at 36 months. Overall survival rate was 91.4% and 74.3%, and MACEs incidence 14.2% and 31.4% at 12 and 36 months, respectively. At the paired intracoronary imaging analysis, a significant increase of the vessel external elastic membrane area in the treated segment and some progression of CAV proximally to the BRS were detected.

CONCLUSIONS

BRS-based PCI for the treatment of CAV is feasible and safe, with an ISSR incidence similar to what reported in retrospective studies with drug-eluting stents.

High sensitivity troponin I as a biomarker for cardiac allograft vasculopathy: Evaluation of diagnostic potential and clinical utility

INTRODUCTION

Cardiac allograft vasculopathy (CAV) limits long-term survival in heart transplant (HTx) recipients. The use of biomarkers in CAV surveillance has been studied, but none are used in clinical practice. The predictive value of high-sensitivity troponin I (hsTnI) has not been extensively investigated in HTx recipients.

METHODS

HTx patients undergoing surveillance coronary angiograms and enrolled in the Emory Cardiovascular Biobank had plasma hsTnI measured. CAV grade was assessed using ISHLT nomenclature. Multivariable cumulative link mixed modeling was performed to determine association between hsTnI level and CAV grade. Patients were followed for adverse outcomes over a median 10-year period. Kaplan-Meier survival analysis and Cox proportional hazard modeling were performed.

RESULTS

Three hundred and seventy-two angiograms were analyzed in 156 patients at a median 8.9 years after transplant. hsTnI levels were positively correlated with concurrent CAV grade after adjustment for age, age at transplant, sex, BMI, hypertension, diabetes, hyperlipidemia, estimated glomerular filtration rate, and history of acute cellular rejection (p = .016). In an adjusted Cox proportional hazard model, initial hsTnI level above the median (4.9 pg/mL) remained a predictor of re-transplantation or death (hazard ratio 1.82; 95% confidence interval 1.16-2.90; p = .01).

CONCLUSION

An elevated hsTnI level reflects severity of CAV and is associated with poor long-term outcomes in patients with HTx.

Serial electrocardiograms at follow-up for early detection of transplanted heart rejection: A viewpoint

This viewpoint proposed that serial electrocardiograms (ECG) could be used to monitor for heart transplantation (HT) rejection, based on the expected attenuation of the amplitude of ECG QRS complexes (attQRS) engendered by the rejection-induced decrease in electrical resistance due to the underlying myocardial edema (ME). Previous work in humans has shown attQRS in the setting of a diverse array of edematous states, affecting the myocardium (i.e, ME) and the body volume conductor "enveloping" the heart. Also, animal and human experience has revealed low electrical resistance during mild/moderate HT rejection. Studies with serial correlations of endomyocardial biopsy (EMB), echocardiography, cardiac magnetic resonance imaging, and ECG are recommended, which will merely require recording of an ECG, when EMB and imaging studies are carried out for monitoring of post-HT rejection.

Heart Transplantation-Postoperative Considerations

Heart transplantation (HT) remains the best treatment of patients with severe heart failure who are deemed to be transplant candidates. The authors discuss postoperative management of the HT recipient by system, emphasizing areas where care might differ from other cardiac surgery patients. Working together, critical care physicians, heart transplant surgeons and cardiologists, advanced practice providers, pharmacists, transplant coordinators, nursing staff, physical therapists, occupational therapists, rehabilitation specialists, nutritionists, health psychologists, social workers, and the patient and their loved ones partner to increase the likelihood of a successful outcome.

Effects of WuZhi preparations on tacrolimus in pediatric and adult patients carrying the CYP3A5*1 allele of heart transplant during the early period after transplantation

AIM

Wuzhi preparations (WZP) are commonly administrated with tacrolimus (TAC) in China to improve the liver function and increase the exposure of TAC. This study aims to investigate the effects of WZP on TAC in pediatric heart transplantation (HTx) patients carrying the CYP3A5*1 allele during the early period after transplantation and also make a comparison with these effects in adult recipients.

METHODS

A total of 81 recipients with CYP3A5*1 allele were included and divided into the pediatric group (n = 29) and adult group (n = 52). The changes in TAC dose-corrected trough blood concentrations (C0 /D), dose requirement as well as intra-patient variability(IPV) of C0 /D after co-therapy with WZP were evaluated.

RESULTS

The TAC C0 /D was significantly increased 1.7 and 1.8 times after co-administration of WZP in the pediatric and adult groups, respectively. We further analyzed the pediatric patients, found that no statistical difference was observed in TAC C0 /D before and after co-therapy with WZP in children <6 years old. The changes of C0 /D increased with the dose of the active ingredient (Schisantherin A) in adult patients, but not in pediatric patients. TAC IPV was reduced by 10.5% in pediatric patients and 4.8% in adult patients when co-administrated with WZP. Furthermore, after taking WZP, the AST and TB were dramatically lowered in pediatric recipients.

CONCLUSION

Our study is the first attempt to demonstrate the effects of WZP on TAC in pediatric HTx recipients. By comparing these effects to those observed in adult recipients, valuable insights can be gained regarding the efficacy and potential benefits of WZP in the pediatric population.

Is the practice of using oversized organs for recipients with elevated pulmonary vascular resistance justified?

OBJECTIVE

The purpose of this study was to assess post-transplantation outcomes in recipients with increased pulmonary vascular resistance (PVR) in relation to donor size.

METHODS

The United Network for Organ Sharing database was used to identify patients ages 0 to 18 years at time of listing who underwent transplantation from 2010 to 2019 and for whom cardiac catheterization and donor-recipient weight ratio data were available. Patients were divided according to listing PVR into <3, 3 to 6, and >6 Wood units. Donor-recipient weight ratio was categorized as undersized (≤0.80), midsize (0.81-1.2), and oversized (>1.2). Subgroup analysis was done with an additional supersized group (>2.0).

RESULTS

Fourteen hundred ninety-one patients met study criteria. Median age was 10 (interquartile range, 3-15) years and 45% were female. Four percent of heart transplantation cases used undersized, 45% used midsize, and 51% used oversized organs. More patients with PVR >6 were received an oversized organ transplant compared with patients with PVR <3; 59% (148/252) versus 48% (430/894); P = .003. There was no difference in survival among organ size groups regardless of PVR; this includes patients with PVR >6 at listing who received an oversized organ transplant versus an undersized (P = .359) or midsized (P = .956) organ. In subgroup analysis, even in patients who received a supersized organ transplant, there was no survival difference noted regardless of PVR.

CONCLUSIONS

Despite a persistent practice pattern to transplant oversized organs in high-PVR patients, there remains no difference in post-transplantation survival among these patients and those who received smaller organ transplants. Therefore, transplants in patients with high PVR should not be delayed by waiting for larger donors.

Plasma tumour necrosis factor-alpha-related proteins in prognosis of heart failure with pulmonary hypertension

AIMS

Patients with heart failure (HF) exhibit poor prognosis, which is further deteriorated by pulmonary hypertension (PH), with negative impact on morbidity and mortality. As PH due to left HF (LHF-PH) is among the most common causes of PH, there is an urge according to the 2021 European Society of Cardiology HF guidelines to find new biomarkers that aid in prognostication of this patient cohort. Given the role of tumour necrosis factor-alpha (TNF-α) in HF progression, we aimed to investigate the prognostic value of plasma proteins related to TNF-α in patients with LHF-PH, in relation to haemodynamic changes following heart transplantation (HT).

METHODS AND RESULTS

Twenty TNF-α-related plasma proteins were analysed using proximity extension assay in healthy controls (n = 20) and patients with LHF-PH (n = 67), before and 1 year after HT (n = 19). Plasma levels were compared between the groups, and the prognostic values were determined using Kaplan-Meier and Cox regression analyses. Plasma levels of lymphotoxin-beta receptor (LTBR), TNF receptor superfamily member 6B (TNFRSF6B), and TNF-related apoptosis-inducing ligand receptors 1 and 2 (TRAIL-R1 and TRAIL-R2, respectively) were higher in LHF-PH pre-HT vs. controls (P < 0.0001), as well as higher in pre-HT vs. post-HT (P < 0.001). The elevated pre-HT levels of LTBR, TNFRSF6B, TRAIL-R1, and TRAIL-R2 decreased towards the levels of healthy controls after HT. Higher preoperative levels of LTBR, TNFRSF6B, TRAIL-R1, and TRAIL-R2 in LHF-PH were associated with worse survival rates (P < 0.002). In multivariate Cox regression models, each adjusted for age and sex, LTBR, TNFRSF6B, TRAIL-R1, and TRAIL-R2 predicted mortality (P < 0.002) [hazard ratio (95% confidence interval): 1.12 (1.04-1.19), 1.01 (1.004-1.02), 1.28 (1.14-1.42), and 1.03 (1.02-1.04), respectively].

CONCLUSIONS

Elevated pre-HT plasma levels of the TNF-α-related proteins LTBR, TNFRSF6B, TRAIL-R1, and TRAIL-R2 in LHF-PH decreased 1 year after HT, displaying a normalization pattern towards the levels of the healthy controls. These proteins were also prognostic, where higher levels were associated with worse survival rates in LHF-PH, providing new insight in their potential role as prognostic biomarkers. Larger studies are warranted to validate our findings and to investigate their possible pathobiological mechanisms in LHF-PH.

Alcohol consumption, alcohol use disorder and organ transplantation

In the present experience we have evaluated the link alcohol consumption/alcohol use disorder (AUD) and organ transplantation (OT) in order to provide adequate suggestions. The data used for the preparation of these recommendations are based on a detailed analysis of the scientific literature published before August 31, 2022 (Web of Science, Scopus, Google Scholar). Furthermore, in the process of developing this work, we consulted the guidelines/position papers of the scientific societies. With regard to the liver transplantation, there are position papers/guidelines that clearly define indications and contraindications for including the AUD patient in the transplant list. One of the major difficulties in this area is psychosocial assessment which can be influenced by stigma. To solve this problem, it is necessary to use objective tools. However, this assessment should be carried out after providing the patient and family adequate tools to be able to create or recreate reliable socio-family support. This behavior should also be used in the case of other OTs. For the latter, however, adequate guidelines must be created which at the moment do not exist or if there are, as in the case of heart transplantation, they are not sufficient. Even in the absence of obvious alcohol addiction, it is recommended to use alcohol use disorder identification test and to include the addiction specialist in the multidisciplinary transplant team. Besides, providing family members with the tools necessary to better support the patient is essential. They are patients with alcohol use disorder/ possible presence of psychopathological manifestations and alcohol-related pathology (cirrhosis, cardiomyopathy, liver-kidney disfunction, etc.). A cardiovascular and oncologic surveillance post-OT is recommended. For the selection of patients to be included in the list for non-LT (heart, lung, kidney, multivisceral, etc.) it is mandatory to include the diagnosis and treatment of AUDs in the guidelines. What has already been indicated for LT may be useful. Timing of alcoholic abstention in relation to clinical severity, optimal psychosocial activity, anticraving therapy in relation to the type of underlying disease and clinical severity. Close collaboration between scientific societies is required to better manage AUD patients who need OT.

Effect of renal function under left ventricular assist device support on the cardiac function and clinical events after heart transplantation

AIM

We investigated the effects of pre-transplantation renal dysfunction under left ventricular assisted device (LVAD) support on post-transplantation cardiac function, and patient prognosis after heart transplantation (HTx).

METHOD

All patients who were bridged by LVAD and underwent HTx at our hospital between 2007 and 2022 were included in this study. Patients were classified into two groups based on estimated glomerular filtration rate (eGFR) before HTx: renal dysfunction (RD) group (eGFR < 60 mL/min/1.73 m2 ) and non-renal dysfunction (NRD) group.

RESULT

A total of 132 patients were analyzed, of whom 48 were classified into the RD group and 84 into the NRD group (RD group, 47.9 ± 10.1 years; NRD group, 38.4 ± 11.9 years, p < .0001). Under LVAD support before HTx, the RD group tended to have a history of right ventricular failure (RD group, nine (19%); NRD group, seven (8%); p = .098). After HTx, the echocardiographic parameters did not differ between the two groups in the long term. Furthermore, more concise hemodynamic parameters, exemplified by right heart catheterization, were not significantly different between the two groups. Regarding graft rejection, no significant differences were found in acute cellular rejection and cardiac allograft vasculopathy following HTx. In contrast, patients with RD before HTx had significantly increased mortality in the chronic phase after HTx and initiation of maintenance dialysis, without any overt changes in cardiac function.

CONCLUSION

Pre-transplantation renal dysfunction under LVAD support significantly affected clinical course after HTx without any overt changes in graft cardiac function.

Machine Learning in Invasive and Noninvasive Coronary Angiography

PURPOSE OF REVIEW

The objective of this review is to shed light on the transformative potential of machine learning (ML) in coronary angiography. We aim to understand existing developments in using ML for coronary angiography and discuss broader implications for the future of coronary angiography and cardiovascular medicine.

RECENT FINDINGS

The developments in invasive and noninvasive imaging have revolutionized diagnosis and treatment of coronary artery disease (CAD). However, CAD remains underdiagnosed and undertreated. ML has emerged as a powerful tool to further improve image analysis, hemodynamic assessment, lesion detection, and predictive modeling. These advancements have enabled more accurate identification of CAD, streamlined workflows, reduced the need for invasive diagnostic procedures, and improved the diagnostic value of invasive procedures when they are needed. Further integration of ML with coronary angiography will advance the prevention, diagnosis, and treatment of CAD. The integration of ML with coronary angiography is ushering in a new era in cardiovascular medicine. We highlight five use cases to leverage ML in coronary angiography: (1) improvement of quality and efficacy, (2) characterization of plaque, (3) hemodynamic assessment, (4) prediction of future outcomes, and (5) diagnosis of non-atherosclerotic coronary disease.

Does the induction immunotherapy (basiliximab) influence the early acute cellular rejection index after orthotopic heart transplantation?- Preliminary assessment report

The study aimed to determine the influence of induction therapy on the acute cellular rejection (ACR) index in adult heart transplant recipients during the one-year observation. The study population consisted of 256 consecutive adult patients (pts), aged 51.5 (±11.9) years, 199 (77%) men treated with orthotopic heart transplantation (OHT) in the period between 2015 and 2020 in a single high-volume heart transplant center. The endomyocardial biopsies (EMBs) were performed according to the protocol consisting of 7 protocolary EMBs for up to 3 months and 10 EMBs for up to one year after OHT. The rejection index (ACRI) was calculated as the number of scheduled EMBs with the ACR ≥ 2 divided by the total number of protocolary EMBs. The study population was divided into two groups according to the application of basiliximab. The total number of pts. who received basiliximab was 10 (3.9%). The main indications for the usage of the induction therapy were heart retransplantation, mechanical circulatory support (MCS), severe renal insufficiency (eGFR <30 mL/min/1.73 m2), and a panel of reactive antibody (PRA) > 10%. In the group with induction, the mean age was 49 (±14) years; 3 (30%) patients had the MCS prior to OHT, and 3 (30%) patients had heart retransplantation. Four (40%) patients had diabetes mellitus, and 4 (40%) patients had severe renal insufficiency. As maintenance therapy during the observation period, tacrolimus was given to 10 (100%) patients, everolimus to 2 (20%) patients, and MPA to 9 (90%) patients. In the group with no induction, the mean age was 51.8 (±12) years, MCS was used in 56 (23%) patients, 2 (0.8%) patients were retransplanted; 10 (4%) patients had eGFR <30 mL/min/1.73 m2 and 58 (24%) patients had diabetes. Tacrolimus was administered to 243 (99%) patients, cyclosporine to 3 (1%), everolimus to 40 (16%), and mycophenolate to 245 (99.6%) heart recipients. The median one-year ACRI was 0.0, IQR:0.0-0.08 in the group with induction vs. 0.077, IQR: 0.0-0.154 with no induction; p = 0.11. ACRI up to three months was significantly higher in the entire cohort in comparison to up to one year (P < 0.01). The multivariate analysis showed that only everolimus implementation and younger age at the time of transplant influenced patients' mortality rate (P < 0.01). Significant graft rejections (≥ 2R ISHLT) are most common in the first three months after OHT. Patients who are initially at high risk of significant cellular rejection may benefit from induction therapy.

Increasing donor-recipient weight mismatch in infant heart transplantation is associated with shorter waitlist duration and no increased morbidity or mortality

OBJECTIVES

Infants awaiting paediatric heart transplantation (PHT) experience long waitlist duration and high mortality due to donor shortage. Using the United Network for Organ Sharing database, we explored if increasing donor-recipient weight ratio (DRWR) >2.0 (recommended cutoff) was associated with adverse outcomes.

METHODS

Between 2007 and 2020, 1392 infants received PHT. We divided cohort into 3 groups: A (DRWR ≤1.0, n = 239, 17%), B (DRWR 1.0-2.0, n = 947, 68%), C (DRWR >2.0, n = 206, 15%). Group characteristics and PHT outcomes were analysed.

RESULTS

DRWR ranged between 0.5 and 4.1. Underlying pathology (congenital versus cardiomyopathy), gender, race, renal function and mechanical circulatory support were comparable between groups. Group C patients were more likely to be ventilated, to receive ABO blood group (ABO)-incompatible heart and to have longer donor ischaemic time. Waitlist duration was significantly shorter for group C (33 vs 50 days, P < 0.1). Early outcomes for groups A, B and C were the following (respectively): operative death (6%, 4%, 3%, P = 0.29), primary graft dysfunction (5%, 3%, 3%, P = 0.30), renal failure (10%, 7%, 7%, P = 0.42) and stroke (3%, 4%, 1%, P = 0.36). The DRWR group was not associated with operative death in either congenital (odds ratio (OR) = 0.819, 95% confidence interval (CI) = 0.523-1.282) or cardiomyopathy (OR = 1.221, 95% CI = 0.780-1.912) patients and only significant factor was pre-PHT extracorporeal membrane oxygenation (OR = 4.400, 95% CI = 2.761-7.010). Additionally, survival at 1 year (87%, 87%, 85%, P = 0.80) and 5 years (76%, 78%, 77%, P = 0.80) was comparable between the DRWR groups.

CONCLUSIONS

Infants who received PHT with DRWR >2.0, up to 4.1, experienced shorter waitlist duration with no demonstrable increase in peri-transplant complications, operative or late mortality. Historic practice to avoid DRWR > 2.0 due to complications (e.g. hypertension-related stroke, graft dysfunction, death) is not currently supported in infants and stretching DRWR acceptance criteria would decrease PHT waitlist duration and potentially improve waitlist complications and mortality.