Retransplant and Medical Therapy for Cardiac Allograft Vasculopathy: International Society for Heart and Lung Transplantation Registry Analysis

The Outcome of Restrictive Cardiac Allograft Physiology in Severe Coronary Allograft Vasculopathy

BACKGROUND

Microvascular dysfunction after heart transplantation leads to restrictive cardiac allograft physiology (RCP), which is classified as severe coronary allograft vasculopathy (CAV); however, the prognosis of RCP remains unclear. Therefore, in this study, we aimed to elucidate the prognosis of RCP in comparison with that of severe angiographic CAV.

METHODS

We assessed 116 patients with severe CAV who underwent heart transplantation between 2004 and 2023. RCP was defined as symptomatic heart failure with restrictive hemodynamic values (mean right atrial pressure >12 mmHg, pulmonary capillary wedge pressure >25 mmHg, and cardiac index <2.0 L/min/m2). The primary outcome was death or re-transplantation.

RESULTS

Of the 116 patients with severe CAV, 42 had RCP (RCP-CAV group) and 74 had severe angiographic CAV without RCP (Angio-CAV group). A significantly shorter time from heart transplantation to diagnosis and lower subsequent percutaneous catheter intervention after diagnosis were seen in the RCP-CAV group than in the Angio-CAV group (both p<0.001). Freedom from death or re-transplantation at 5 years was significantly worse in the RCP-CAV group compared to the Angio-CAV group (18.4% vs 35.4%, p=0.001). In the Cox proportional hazard model, RCP was independently associated with an increased risk of death or re-transplantation (hazard ratio 2.08, 95% confidence intervals 1.26-3.44, p=0.004).

CONCLUSIONS

The prognosis of patients with RCP was significantly worse than that of patients with severe angiographic CAV. The early detection of microvascular dysfunction and re-transplantation listing may improve the prognosis of patients with RCP.

Transplant Vasculopathy Versus Native Atherosclerosis: Similarities and Differences

Cardiac allograft vasculopathy (CAV) is one of the leading causes of graft failure and death after heart transplantation. Alloimmune-dependent and -independent factors trigger the pathogenesis of CAV through activation of the recipients' (and to a lesser extent donor-derived) immune system. Early diagnosis of CAV is complicated by the lack of clinical symptoms for ischemia in the denervated heart, by the impact of early functional coronary alterations, by the insensitivity of coronary angiography, and by the involvement of small intramyocardial vessels. CAV in general is a panarterial disease confined to the allograft and characterized by diffuse concentric longitudinal intimal hyperplasia in the epicardial coronary arteries and concentric medial disease in the microvasculature. Plaque composition in CAV may include early fibrous and fibrofatty tissue and late atheromatous calcification. In contrast, native coronary atherosclerosis usually develops over decades, is focal, noncircumferential, and typically diminishes proximal parts of the epicardial vessels. The rapid and early development of CAV has an adverse prognostic impact, and current prevention and treatment strategies are of limited efficacy compared with established strategies in native atherosclerosis. Following acute coronary syndromes, patients after heart transplantation were more likely to have accompanying cardiogenic shock and higher mortality compared with acute coronary syndromes patients with native hearts.

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.

Coronary Artery Revascularization in Heart Transplant Patients: A Systematic Review and Meta-analysis

BACKGROUND

Cardiac allograft vasculopathy (CAV) is the primary cause of late mortality after heart transplantation (HTx). We look to provide a comprehensive review of contemporary revascularization strategies in CAV.

METHODS

PubMed and Web of Science were systematically searched by 3 authors. 1,870 articles were initially screened and 24 were included in this review.

RESULTS

PCI is the main revascularization technique utilized in CAV. The pooled estimates for restenosis significantly favored DES over BMS (OR 4.26; 95% CI, 2.54-7.13; p< 0.00001; I2=4%). There was insufficient data to quantitatively compare mortality following DES versus BMS. There was no difference in short-term mortality between CABG and PCI. In-hospital mortality was 0.0% for CABG and ranged from 0.0-8.34% for PCI. 1-year mortality was 8.0% for CABG and 5.0-25.0% for PCI. CABG had a potential advantage at 5 years. 5-year mortality was 17.0% for CABG and ranged from 14-40.4% following PCI. Select measures of postoperative morbidity trended towards superior outcomes for CABG.

CONCLUSIONS

In CAV, PCI is the primary revascularization strategy utilized, with DES exhibiting superiority to BMS regarding postoperative morbidity. Further investigation into outcomes following CABG in CAV is required to conclusively elucidate the superior management strategy in CAV.

Cardiac allograft vasculopathy: current review and future research directions

Cardiac allograft vasculopathy (CAV) is a pathologic immune-mediated remodelling of the vasculature in transplanted hearts and, by impairing perfusion, is the major cause of late graft loss. Although best understood following cardiac transplantation, similar forms of allograft vasculopathy occur in other vascularized organ grafts and some features of CAV may be shared with other immune-mediated vasculopathies. Here, we describe the incidence and diagnosis, the nature of the vascular remodelling, immune and non-immune contributions to pathogenesis, current therapies, and future areas of research in CAV.

Cardiac allograft vasculopathy after heart transplantation: Pathophysiology, detection approaches, prevention, and treatment management

Cardiac allograft vasculopathy (CAV) continues to be a significant risk factor for the recipient's long-term survival following heart transplantation. Our knowledge of its etiology is constantly changing as new imaging techniques provide direct insight into the disease's natural history. CAV identification continues to be difficult since symptoms may be varied or nonexistent. Due to the irreversible nature of the disease, early diagnosis is critical to halting development. Prognostic tools and biomarkers have proliferated as a result of advancements in diagnostic techniques. Simultaneously, pharmaceutical advancements have aided in the amelioration of the disease's progressive progression.

Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement on Heart Transplantation: Patient Eligibility, Selection, and Post-Transplantation Care

Significant practice-changing developments have occurred in the care of heart transplantation candidates and recipients over the past decade. This Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement provides evidence-based, expert panel recommendations with values and preferences, and practical tips on: (1) patient selection criteria; (2) selected patient populations; and (3) post transplantation surveillance. The recommendations were developed through systematic review of the literature and using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The evolving areas of importance addressed include transplant recipient age, frailty assessment, pulmonary hypertension evaluation, cannabis use, combined heart and other solid organ transplantation, adult congenital heart disease, cardiac amyloidosis, high sensitization, and post-transplantation management of antibodies to human leukocyte antigen, rejection, cardiac allograft vasculopathy, and long-term noncardiac care. Attention is also given to Canadian-specific management strategies including the prioritization of highly sensitized transplant candidates (status 4S) and heart organ allocation algorithms. The focus topics in this position statement highlight the increased complexity of patients who undergo evaluation for heart transplantation as well as improved patient selection, and advances in post-transplantation management and surveillance that have led to better long-term outcomes for heart transplant recipients.

Cardiac allograft vasculopathy: Insights on pathogenesis and therapy

Cardiac allograft vasculopathy (CAV) is a unique accelerated form of coronary vascular disease affecting heart transplant recipients. This complication is a significant contributor to medium- to long-term post-transplant morbidity and mortality. There is a high prevalence of CAV with approximately one in three patients developing CAV by 5 years post-transplant. Morphologically, CAV is characterized by concentric coronary intimal hyperplasia in both the epicardial arteries and intramural microvasculature. Although several immune and non-immune factors have been identified, their precise pathogenic mechanisms, interactions, and relative importance in the development of CAV are not well defined. The advent of improved imaging surveillance modalities has resulted in earlier detection during the disease process. However, overall management of CAV remains challenging due to paucity of treatment. This review aims to discuss key concepts on the pathogenesis of CAV and current management strategies, focusing on the use of mammalian target of rapamycin inhibitors.

Percutaneous coronary intervention for coronary allograft vasculopathy with drug-eluting stent in Indian subcontinent: Issues in diagnosis and management

Coronary allograft vasculopathy fails to give a warning anginal pain due to denervation and often presents with acute coronary syndrome, ventricular dysfunction, or sudden cardiac death. Early diagnosis in a pediatric patient is difficult as it involves invasive coronary angiography or advanced imaging such as intravascular ultrasound or optical coherence tomography. A 12-year-old boy developed acute coronary syndrome, elevated troponins, and right bundle branch block, 5 years after cardiac transplantation and was treated with culprit-vessel angioplasty with a drug-eluting stent. Advanced imaging showed the involvement of nonculprit vessels too. In a detailed literature search, we failed to identify a similar clinical presentation and management in the subcontinent, hence our interest in publishing this report for educational value. Issues in diagnosis, management, prognosis, and prevention are discussed.

Heart re-transplantation in Eurotransplant

Internationally 3% of the donor hearts are distributed to re-transplant patients. In Eurotransplant, only patients with a primary graft dysfunction (PGD) within 1 week after heart transplantation (HTX) are indicated for high urgency listing. The aim of this study is to provide evidence for the discussion on whether these patients should still be allocated with priority. All consecutive HTX performed in the period 1981-2015 were included. Multivariate Cox' model was built including: donor and recipient age and gender, ischaemia time, recipient diagnose, urgency status and era. The study population included 18 490 HTX, of these 463 (2.6%) were repeat transplants. The major indications for re-HTX were cardiac allograft vasculopathy (CAV) (50%), PGD (26%) and acute rejection (21%). In a multivariate model, compared with first HTX hazards ratio and 95% confidence interval for repeat HTX were 2.27 (1.83-2.82) for PGD, 2.24 (1.76-2.85) for acute rejection and 1.22 (1.00-1.48) for CAV (P < 0.0001). Outcome after cardiac re-HTX strongly depends on the indication for re-HTX with acceptable outcomes for CAV. In contrast, just 47.5% of all hearts transplanted in patients who were re-transplanted for PGD still functioned at 1-month post-transplant. Alternative options like VA-ECMO should be first offered before opting for acute re-transplantation.