The Donation-after-Circulatory-Death (DCD) heart transplantation program increases donor pool but resulting in more serious ischemic-related myocardial injury (IRI), leading to higher incidence of primary graft dysfunction (PGD). Ex-vivo machine perfusion (EVMP) for DCD heart is being considered a useful aid in improving grafts number and quality assessment, aiming to better outcomes. In this review we will analyze the role of EVMP techniques in the context of DCD with special attention to their clinical aims and results and future perspectives. A review of available clinical and pre-clinical studies involving EVMP with DCD donation model was performed. Thirty-four original articles about preclinical studies were found. First studies were designed to evaluate graft function in DCD hearts after EVMP, while recent research focus on possible therapies that could be associated with EVMP. Twenty-one original articles about clinical studies were found with the Organ-Care-System (TransMedics) as MP used. Outcomes, such as survival rates or rejection episodes, are comparable to outcomes from donation-after-brain-death. EVMP in the setting of DCD heart transplantation can be a valid tool for organ preservation and transport. The role of pre-clinical research will be crucial to reduce IRI, achieve organ reconditioning and reduce incidence of PGD.
Heart transplantation (HT) is the established treatment for end-stage heart failure, significantly enhancing patients’ survival and quality of life. To ensure optimal outcomes, the routine monitoring of HT recipients is paramount. While existing guidelines offer guidance on a blend of invasive and non-invasive imaging techniques, certain aspects such as the timing of echocardiographic assessments and the role of echocardiography or cardiac magnetic resonance (CMR) as alternatives to serial endomyocardial biopsies (EMBs) for rejection monitoring are not specifically outlined in the guidelines. Furthermore, invasive coronary angiography (ICA) is still recommended as the gold-standard procedure, usually performed one year after surgery and every two years thereafter. This review focuses on recent advancements in non-invasive and contrast-saving imaging techniques that have been investigated for HT patients. The aim of the manuscript is to identify imaging modalities that may potentially replace or reduce the need for invasive procedures such as ICA and EMB, considering their respective advantages and disadvantages. We emphasize the transformative potential of non-invasive techniques in elevating patient care. Advanced echocardiography techniques, including strain imaging and tissue Doppler imaging, offer enhanced insights into cardiac function, while CMR, through its multi-parametric mapping techniques, such as T1 and T2 mapping, allows for the non-invasive assessment of inflammation and tissue characterization. Cardiac computed tomography (CCT), particularly with its ability to evaluate coronary artery disease and assess graft vasculopathy, emerges as an integral tool in the follow-up of HT patients. Recent studies have highlighted the potential of nuclear myocardial perfusion imaging, including myocardial blood flow quantification, as a non-invasive method for diagnosing and prognosticating CAV. These advanced imaging approaches hold promise in mitigating the need for invasive procedures like ICA and EMB when evaluating the benefits and limitations of each modality.
Background: Heart transplant rejection, particularly acute cellular rejection (ACR), remains a critical post-operative concern, despite declining incidence rates. Current diagnostic standards rely on invasive endomyocardial biopsy, which presents limitations in sensitivity and reproducibility. There is an unmet need for noninvasive, accurate biomarkers that can detect and monitor rejection. This study aims to evaluate whether extracellular vesicle (EV) surface antigens, analyzed through flow cytometry and interpreted with artificial intelligence (AI), can serve as reliable biomarkers for ACR detection and monitoring in heart transplant recipients. Methods: We conducted a prospective longitudinal cohort study involving 24 heart transplant recipients over a median follow-up of 303 days. A total of 285 blood samples were analyzed for EV surface antigens exploiting two flow cytometry-based protocols. An adaptive AI model (random forest regressor) was developed to interpret EV antigen profiles, dynamically calibrating thresholds per patient. Results: Here we show that 14 EV surface antigens progressively increase with ACR severity. These changes are evident even before histological diagnosis. The AI model achieves an accuracy of 93.3% at leave-one-out testing (AUC 0.968), and 78.9% at validation in an independent cohort (AUC 0.832), with high specificity and negative predictive value. EV profiling outperforms conventional biochemical markers and provides anticipatory insight into rejection dynamics. Conclusions: EV profiling, enhanced by patient-specific AI modeling, offers a powerful noninvasive method for early detection and monitoring of ACR. This approach holds the potential to reduce reliance on biopsies and tailor immunosuppressive strategies more precisely.
When approaching infected lead removal in cardiac device-related infective endocarditis (CDRIE), a surgical consideration for large (>20 mm) vegetations is recommended. We report our experience with the removal of large CDRIE vegetations using the AngioVac system, as an alternative to conventional surgery. We retrospectively reviewed all infected lead extractions performed with a prior debulking using the AngioVac system, between October 2016 and April 2022 at our institution. A total of 13 patients presented a mean of 2(1) infected leads after a mean of 5.7(5.7) years from implantation (seven implantable cardioverter-defibrillators, four cardiac resynchronization therapy-defibrillators, and two pacemakers). The AngioVac system was used as a venous–venous bypass in six cases (46.2%), venous–venous ECMO-like circuit (with an oxygenator) in five (38.5%), and venous–arterial ECMO-like circuit in two cases (15.4%). Successful (>70%) aspiration of the vegetations was achieved in 12 patients (92.3%) and an intraoperative complication (cardiac perforation) only occurred in 1 case (7.7%). Subsequent lead extraction was successful in all cases, either manually (38.5%) or using mechanical tools (61.5%). The AngioVac system is a promising effective and safe option for large vegetation debulking in CDRIE. Planning the extracorporeal circuit design may represent the optimal strategy to enhance the tolerability of the procedure and minimize adverse events.
20 July 2024 in Journal of Cardiovascular Computed Tomography
Cardiac allograft vasculopathy (CAV) assessment post-heart transplantation (HT) typically relies on invasive coronary angiography (ICA). However, cardiac computed tomography angiography (CCTA) is emerging as a promising alternative due to its potential benefits in economic, safety, and logistical aspects. This study aimed to evaluate the impact of a CCTA program on these aspects in CAV surveillance post-HT. A retrospective single-center study was conducted between March 2021 and February 2023, involving HT patients who underwent either CCTA or ICA. Among 260 patients undergoing CAV surveillance, 115 (44.2%) patients underwent CCTA, and 145 (55.8%) patients underwent ICA. The CCTA group showed incurred lower overall costs (p < 0.0001) and shorter hospitalization times (p < 0.0001) compared to the ICA group. In terms of safety, CCTA surveillance required significantly lower contrast volumes (p < 0.0001) and lower effective doses (p = 0.03). CCTA emerges as a safe and cost-effective non-invasive alternative for CAV surveillance post-HT, outperforming ICA in terms of safety, logistical aspects, and economic burden.
6 April 2021 in Journal of Cardiovascular Electrophysiology