Cost-Effectiveness of Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation in the Australian Health Care System.

BACKGROUND: Heart transplantation is an effective treatment for end-stage congestive heart failure, however, achieving the right balance of immunosuppression to maintain graft function while minimising adverse effects is challenging. Serial endomyocardial biopsies (EMBs) are currently the standard for rejection surveillance, despite being invasive. Replacing EMB-based surveillance with cardiac magnetic resonance (CMR)-based surveillance for acute cardiac allograft rejection has shown feasibility. This study aimed to assess the cost-effectiveness of CMR-based surveillance in the first year after heart transplantation. METHOD: A prospective clinical trial was conducted with 40 orthotopic heart transplant (OHT) recipients. Participants were randomly allocated into two surveillance groups: EMB-based, and CMR-based. The trial included economic evaluations, comparing the frequency and cost of surveillance modalities in relation to quality-adjusted life years (QALYs) within the first year post-transplantation. Sensitivity analysis encompassed modelled data from observed EMB and CMR arms, integrating two hypothetical models of expedited CMR-based surveillance. RESULTS: In the CMR cohort, 238 CMR scans and 15 EMBs were conducted, versus (vs) 235 EMBs in the EMB group. CMR surveillance yielded comparable rejection rates (CMR 74 vs EMB 94 events, p=0.10) and did not increase hospitalisation risk (CMR 32 vs EMB 46 events, p=0.031). It significantly reduced the necessity for invasive EMBs by 94%, lowered costs by an average of AUD$32,878.61, and enhanced cumulative QALY by 0.588 compared with EMB. Sensitivity analysis showed that increased surveillance with expedited CMR Models 1 and 2 were more cost-effective than EMB (all p<0.01), with CMR Model 1 achieving the greatest cost savings (AUD$34,091.12±AUD$23,271.86 less) and utility increase (+0.62±1.49 QALYs, p=0.011), signifying an optimal cost-utility ratio. Model 2 showed comparable utility to the base CMR model (p=0.900) while offering the benefit of heightened surveillance frequency during periods of elevated rejection risk. CONCLUSIONS: CMR-based rejection surveillance in orthotopic heart transplant recipients provides a cost-effective alternative to EMB-based surveillance. Furthermore, it reduces the need for invasive procedures, without increased risk of rejection or hospitalisation for patients, and can be incorporated economically for expedited surveillance. These findings have important implications for improving patient care and optimising resource allocation in post-transplant management.

Molecular magnetic resonance imaging of myeloperoxidase activity identifies culprit lesions and predicts future atherothrombosis.

Aims: Unstable atherosclerotic plaques have increased activity of myeloperoxidase (MPO). We examined whether molecular magnetic resonance imaging (MRI) of intraplaque MPO activity predicts future atherothrombosis in rabbits and correlates with ruptured human atheroma. Methods and results: Plaque MPO activity was assessed in vivo in rabbits (n = 12) using the MPO-gadolinium (Gd) probe at 8 and 12 weeks after induction of atherosclerosis and before pharmacological triggering of atherothrombosis. Excised plaques were used to confirm MPO activity by liquid chromatography-tandem mass spectrometry (LC-MSMS) and to determine MPO distribution by histology. MPO activity was higher in plaques that caused post-trigger atherothrombosis than plaques that did not. Among the in vivo MRI metrics, the plaques' R1 relaxation rate after administration of MPO-Gd was the best predictor of atherothrombosis. MPO activity measured in human carotid endarterectomy specimens (n = 30) by MPO-Gd-enhanced MRI was correlated with in vivo patient MRI and histological plaque phenotyping, as well as LC-MSMS. MPO-Gd retention measured as the change in R1 relaxation from baseline was significantly greater in histologic and MRI-graded American Heart Association (AHA) type VI than type III-V plaques. This association was confirmed by comparing AHA grade to MPO activity determined by LC-MSMS. Conclusion: We show that elevated intraplaque MPO activity detected by molecular MRI employing MPO-Gd predicts future atherothrombosis in a rabbit model and detects ruptured human atheroma, strengthening the translational potential of this approach to prospectively detect high-risk atherosclerosis.

Cardiotoxicity in autologous haematopoietic stem cell transplantation for systemic sclerosis.

Autologous haematopoietic stem cell transplantation is now well-established as an effective treatment for severe systemic sclerosis with clear demonstration of favourable end-organ and survival outcomes. Treatment-related cardiotoxicity remains the predominant safety concern and contraindicates autologous haematopoietic stem cell transplantation in patients with severe cardiopulmonary disease. In this review, we describe the cardiovascular outcomes of autologous haematopoietic stem cell transplantation recipients, discuss the potential mechanisms of cardiotoxicity and propose future mitigating strategies.

Metabolic Sequelae of Everolimus Treatment After Cardiac Transplant: A Hypothesis-Generating Study.

BACKGROUND: Although modern immunosuppressants improve survival post-transplant, they are associated with long-term metabolic complications, such as post-transplant diabetes mellitus (PTDM). Calcineurin inhibitor-sparing regimens using everolimus attenuate some complications such as left ventricular hypertrophy. However, the metabolic effects of everolimus following transplant are less clear. METHODS: Post-hoc analysis to compare PTDM and other metabolic outcomes in participants of a randomised open-label clinical trial of low-dose everolimus and tacrolimus versus standard-dose tacrolimus in heart transplant recipients (RADTAC1 study). RESULTS: There were 39 participants in the trial; mean follow-up was 6.4±1.5 years. There was a high rate of pre-existing diabetes (26%) and newly diagnosed PTDM (36%) during follow-up. Half the patients who developed PTDM in the everolimus-tacrolimus group (n=4/8) ceased diabetes medications during follow-up, which was not observed in patients on standard tacrolimus (n=0/6). In the first 12 months there was a higher use of non-insulin treatment for diabetes in the everolimus-tacrolimus group compared to the standard tacrolimus group. CONCLUSIONS: This study suggests that treatment with everolimus may be associated with improved glycaemic control of PTDM relative to treatment with standard doses of calcineurin inhibitor. These findings should be further studied in prospective randomised trials.

Atrial cardiomyopathy: Current and future imaging methods for assessment of atrial structure and function.

Changes in atrial size and function have historically been considered a surrogate marker of ventricular dysfunction. However, it is now recognized that atrial cardiomyopathy (ACM) may also occur as a primary myocardial disorder. Emerging evidence that ACM is a major risk factor for atrial fibrillation, heart failure, and thromboembolic stroke, has highlighted the significance of this disorder and the need for better assessment of atrial metrics in clinical practice. Key barriers in this regard include a lack of standardized criteria or hierarchy for the diagnosis of ACM and lack of consensus for the most accurate phenotyping methods. In this article we review existing literature on ACM, with a focus on current and future non-invasive imaging methods for detecting abnormalities of atrial structure and function. We discuss the relative advantages and disadvantages of transthoracic echocardiography and cardiac magnetic resonance imaging for assessing a range of parameters, including atrial size and contractile function, strain, tissue characteristics, and epicardial adipose tissue. We will also present the potential application of novel imaging methods such as sphericity index and four- or five-dimensional flow.

Characteristic changes to pulsatile and steady-state load according to pulmonary hypertension classification.

It is of increasing importance to understand and predict changes to the systemic and pulmonary circulations in pulmonary hypertension (PH). To do so, it is necessary to describe the circulation in complete quantitative terms. Characteristic impedance (Zc) expresses opposition of the circulation to pulsatile blood flow. Evaluation of systemic and pulmonary Zc relationships according to PH classification has not previously been described. Prospective study of 40 clinically indicated patients referred for CMR and RHC (56 ± 18 years; 70% females, eight mPAP ≤ 25 mmHg, 16 pre-capillary [Pre-cPH], eight combined pre- and post-capillary [Cpc-PH] and eight isolated left-heart disease [Ipc-PH]). CMR provided assessment of ascending aortic (Ao) and pulmonary arterial (PA) flow, and RHC, central Ao and PA pressure. Systemic and pulmonary Zc were expressed as the relationship of pressure to flow in the frequency domain. Baseline demographic characteristics were well-matched across PH subclasses. In those with a mPAP ≤25mHg, systemic Zc and SVR were >2 times higher than pulmonary Zc and PVR. Only Pre-cPH was associated with inverse pulsatile (systemic Zc 58 [45-69] vs pulmonary Zc 70 [58-85]), but not steady-state (SVR 1101 [986-1752] vs. PVR 483 [409-557]) relationships. Patients with CpcPH and IpcPH had concordant pulsatile and steady-state relationships (Graphical Abstract). Measurement of, and the relationship between, systemic and pulmonary Zc in patients according to PH sub-classification has not previously been described. Systemic Zc was routinely higher than pulmonary Zc, except in patients with newly diagnosed Pre-cPH, where inverse pulsatile but not steady-state relationships were observed.

Tricuspid Regurgitation After Heart Transplantation: The Cause or the Result of Graft Dysfunction?

BACKGROUND: Tricuspid regurgitation (TR) is common following heart transplantation and has been shown to adversely influence patient outcomes. The aim of this study was to identify causes of progression to moderate-severe TR in the first 2 y after transplantation. METHODS: This was a retrospective, single-center study of all patients who underwent heart transplantation over a 6-y period. Transthoracic echocardiogram (TTE) was performed at month 0, between 6 and 12 mo, and 1-2 y postoperatively to determine the presence and severity of TR. RESULTS: A total of 163 patients were included, of whom 142 underwent TTE before first endomyocardial biopsy. At month 0, 127 (78%) patients had nil-mild TR before first biopsy, whereas 36 (22%) had moderate-severe TR. In patients with nil-mild TR, 9 (7%) progressed to moderate-severe TR by 6 mo and 1 underwent tricuspid valve (TV) surgery. Of patients with moderate-severe TR before first biopsy, by 2 y, 3 had undergone TV surgery. The use of postoperative extracorporeal membrane oxygenation (ECMO) in the latter group was significant (78%; P < 0.05) as was rejection profile ( P = 0.02). Patients with late progressive moderate-severe TR had a significantly higher 2-y mortality than those who had moderate-severe TR immediately. CONCLUSIONS: Overall, our study has shown that in the 2 main groups of interest (early moderate-severe TR and progression from nil-mild to moderate-severe TR), TR is more likely to be the result of significant underling graft dysfunction rather than the cause of it.

Sodium glucose co-transporter 2 inhibition with empagliflozin on metabolic, cardiac and renal outcomes in recent cardiac transplant recipients (EMPA-HTx): protocol for a randomised controlled trial.

INTRODUCTION: Cardiac transplantation (CTx) is a life-saving operation that can improve the quality and length of a recipient's life. Immunosuppression medication, required to prevent rejection, can result in adverse metabolic and renal effects. Clinically significant complications include metabolic effects such as diabetes and weight gain, renal impairment, and cardiac disease such as allograft vasculopathy and myocardial fibrosis. Sodium glucose co-transporter 2 (SGLT2) inhibitors are a class of oral medication that increase urinary excretion of glucose. In patients with type 2 diabetes, SGLT2 inhibitors improve cardiovascular, metabolic and renal outcomes. Similar benefits have been shown in patients with heart failure and reduced ejection fraction irrespective of diabetes status. In patients with post-transplant diabetes mellitus, SGLT2 inhibitors improve metabolic parameters; however, their benefit and safety have not been evaluated in randomised prospective studies. This study will potentially provide a novel therapy to improve or prevent complications (diabetes, kidney failure and heart fibrosis) that occur with immunosuppressive medications. METHODS: The EMPA-HTx study is a randomised, placebo-controlled trial of the SGLT2 inhibitor empagliflozin 10 mg daily versus placebo in recent CTx recipients. One hundred participants will be randomised 1:1 and commence the study medication within 6-8 weeks of transplantation with treatment and follow-up until 12 months after transplantation. Demographic information, anthropomorphic measurements, pathology tests and cardiac magnetic resonance (CMR) scan will be recorded at baseline and follow-up. Patients will be reviewed monthly during the study until 12 months post-CTx and data will be collected for each patient at each study visit. The overall aim of the study is to assess the safety and efficacy of empagliflozin in CTx recipients. The primary outcome is glycaemic improvement measured as change in glycated haemoglobin and/or fructosamine. Key secondary outcomes are cardiac interstitial fibrosis measured by CMR and renal function measured by estimated glomerular filtration rate. ETHICS AND DISSEMINATION: This study has been approved by St Vincent's Hospital Human Research Ethics Committee (2021/ETH12184). The findings will be presented at national and international scientific meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ACTRN12622000978763.

Prognostic role of pulmonary impedance estimation to predict right ventricular dysfunction in pulmonary hypertension.

BACKGROUND: The effect of pulmonary hypertension (PH) on right ventricular (RV) afterload is commonly defined by elevation of pulmonary artery (PA) pressure or pulmonary vascular resistance (PVR). In humans however, one-third to half of the hydraulic power in the PA is contained in pulsatile components of flow. Pulmonary impedance (Zc) expresses opposition of the PA to pulsatile blood flow. We evaluate pulmonary Zc relationships according to PH classification using a cardiac magnetic resonance (CMR)/right heart catheterization (RHC) method. METHODS: Prospective study of 70 clinically indicated patients referred for same-day CMR and RHC [60 ± 16 years; 77% females, 16 mPAP <25 mmHg (PVR <240 dynes.s.cm-5 /mPCWP <15 mmHg), 24 pre-capillary (PrecPH), 15 isolated post-capillary (IpcPH), 15 combined pre-capillary/post-capillary (CpcPH)]. CMR provided assessment of PA flow, and RHC, central PA pressure. Pulmonary Zc was expressed as the relationship of PA pressure to flow in the frequency domain (dynes.s.cm-5 ). RESULTS: Baseline demographic characteristics were well matched. There was a significant difference in mPAP (P < 0.001), PVR (P = 0.001), and pulmonary Zc between mPAP<25 mmHg patients and those with PH (mPAP <25 mmHg: 47 ± 19 dynes.s.cm-5 ; PrecPH 86 ± 20 dynes.s.cm-5 ; IpcPH 66 ± 30 dynes.s.cm-5 ; CpcPH 86 ± 39 dynes.s.cm-5 ; P = 0.05). For all patients with PH, elevated mPAP was found to be associated with raised PVR (P < 0.001) but not with pulmonary Zc (P = 0.87), except for those with PrecPH (P < 0.001). Elevated pulmonary Zc was associated with reduced RVSWI, RVEF, and CO (all P < 0.05), whereas PVR and mPAP were not. CONCLUSIONS: Raised pulmonary Zc was independent of elevated mPAP in patients with PH and more strongly predictive of maladaptive RV remodelling than PVR and mPAP. Use of this straightforward method to determine pulmonary Zc may help to better characterize pulsatile components of RV afterload in patients with PH than mPAP or PVR alone.

Rapid triage and transition to telehealth for heart transplant patients in the COVID-19 pandemic setting.

BACKGROUND: In the setting of the COVID-19 pandemic, a rapid uptake of telehealth services was instituted with the aim of reducing the spread of disease to vulnerable patient populations including heart transplant recipients. METHODS: Single-center, cohort study of all heart transplant patients seen by our institution's transplant program during the first 6 weeks of transition from in-person consultation to telehealth (23 March - 5 June 2020). RESULTS: Face-to-face consultation allocation strongly favored patients in the early post-operative period (34 vs. 242 weeks post-transplant; p < 0.001). Telehealth consultation dramatically reduced patient travel and wait times (80 min per visit saved in telehealth patients). No apparent excess re-hospitalization or mortality was seen in telehealth patients. CONCLUSIONS: With appropriate triage, telehealth was feasible in heart transplant recipients, with videoconferencing being the preferred modality. Patients seen face-to-face were those triaged to be higher acuity based on time since transplant and overall clinical status. These patients have the expected higher rates of hospital re-admission, and therefore should continue to be seen in person.

Arterial myeloperoxidase in the detection and treatment of vulnerable atherosclerotic plaque: a new dawn for an old light.

Intracellular myeloperoxidase (MPO) plays a specific role in the innate immune response; however, upon release into the extracellular space in the setting of inflammation, drives oxidative tissue injury. Extracellular MPO has recently been shown to be abundant in unstable atheroma and causally linked to plaque destabilization, erosion, and rupture, identifying it as a potential target for the surveillance and treatment of vulnerable atherosclerosis. Through the compartmentalization of MPO's protective and deleterious effects, extracellular MPO can be selectively detected using non-invasive molecular imaging and targeted by burgeoning pharmacotherapies. Given its causal relationship to plaque destabilization coupled with an ability to preserve its beneficial properties, MPO is potentially a superior translational inflammatory target compared with other immunomodulatory therapies and imaging biomarkers utilized to date. This review explores the role of MPO in plaque destabilization and provides insights into how it can be harnessed in the management of patients with vulnerable atherosclerotic plaque.

Heart Transplantation From DCD Donors in Australia: Lessons Learned From the First 74 Cases.

Heart transplantation from donation after circulatory death (DCD) donors has the potential to substantially increase overall heart transplant activity. The aim of this report is to review the first 8 y of our clinical heart transplant program at St Vincent's Hospital Sydney, to describe how our program has evolved and to report the impact that changes to our retrieval protocols have had on posttransplant outcomes. Since 2014, we have performed 74 DCD heart transplants from DCD donors utilizing a direct procurement protocol followed by normothermic machine perfusion. Changes to our retrieval protocol have resulted in a higher retrieval rate from DCD donors and fewer rejections of DCD hearts during normothermic machine perfusion. Compared with our previously reported early experience in the first 23 transplants, we have observed a significant reduction in the incidence of severe primary graft dysfunction from 35% (8/23) to 8% (4/51) in the subsequent 51 transplant recipients ( P < 0.01). The only withdrawal time interval significantly associated with severe primary graft dysfunction was the asystolic warm ischemic time: 15 (12-17) versus 13 (11-14) min ( P < 0.05). One- and 5-y survival of DCD heart transplant recipients was 94% and 88%, comparable to that of a contemporary cohort of donation after brain death recipients: 87 and 81% ( P -value was not significant). In conclusion, heart transplantation from DCD donors has become a major contributor to our overall transplant activity accounting for almost 30% of all transplants performed by our program in the last 2 y, with similar DCD and donation after brain death outcomes.

Diabetes medication following heart transplantation: a focus on novel cardioprotective therapies-a joint review from endocrinologists and cardiologists.

There is accumulating evidence that novel glucose-lowering agents infer potent cardiovascular and renal benefits. Therefore, it is imperative to reassess the management of post-transplant diabetes mellitus and consider the role of newer agents. With improved transplant-related survival and high prevalence of post-transplant diabetes, management of long-term complications such as diabetes are increasingly important. There are limited guidelines to assist in choice of appropriate agents after solid organ transplantation. Traditional therapies including insulin and sulfonylureas may still have a role; however, other agents should be considered prior. The evidence of novel glucose-lowering agents in post-transplant care is limited, and most studies have focused on kidney transplant recipients. While there are some parallels between renal and cardiac transplant recipients, the potential cardiovascular benefits, particularly on cardiac fibrosis are unique to cardiac transplantation. The treatment of diabetes, with a focus on additional cardiac and renal benefits, needs to be brought to the forefront of post-transplant care with incorporation of recent evidence outside of transplantation. The role for novel glucose-lowering agents in cardiac transplant recipients will be explored, with a summary of available evidence.

Pulsatile energy consumption as a surrogate marker for vascular afterload improves with time post transcatheter aortic valve replacement in patients with aortic stenosis.

The effect of arterial stiffening on elevated pulsatile left ventricular afterload patients with aortic stenosis (AS) is pronounced beyond systemic hypertension. Circulatory afterload pulsatile efficiency (CAPE) is a marker of vascular function, defined as the ratio of steady state energy consumption (SEC) to maintain systemic circulation and pulsatile energy consumption (PEC). Twenty patients aged 80 ± 7 years were assessed at baseline and a median of 60 days post transcatheter aortic valve replacement (TAVR), with pulsatile vascular load calculated using simultaneous radial applanation tonometry derived aortic pressure and cardiac magnetic resonance phase-contrast imaging derived ascending aortic flow. Eight out of 20 patients had a reduction in PEC post TAVR, and the reduction of PEC correlated strongly with the number of days post TAVR (R = 0.62, P < 0.01). Patients assessed within the 100 days of TAVR had a rise in their PEC when compared to baseline (0.19 ± 0.09 vs 0.14 ± 0.08 W, P = 0.04). Baseline PEC correlated moderately with baseline SEC (R = 0.49, P = 0.03), and a high baseline PEC was predictive of post TAVR PEC reduction (R = 0.54, P =0.01). Overall, no significant differences were found between baseline and post TAVR for systolic aortic pressure (131 ± 20 vs 131 ± 20 mmHg), systemic vascular resistance (1894 ± 493 vs 2015 ± 519 dynes.s/cm5), aortic valve ejection time (337 ± 22 vs 324 ± 34 ms) or aortic characteristic impedance (120 ± 48 vs 107 ± 41 dynes.s/cm5). Improved flow profiles after TAVR likely unmask the true vascular properties by altering ventriculo-valvulo-arterial coupling, leading to downstream vascular remodelling secondary to flow conditioning, and results in eventual improvement of pulsatile afterload as reflected by our proposed index of CAPE.

Intraplaque Myeloperoxidase Activity as Biomarker of Unstable Atheroma and Adverse Clinical Outcomes in Human Atherosclerosis.

Background: The detection of unstable atherosclerosis remains elusive. Intraplaque myeloperoxidase (MPO) activity causes plaque destabilization in preclinical models, holding promise for clinical translation as a novel imaging biomarker. Objectives: The purpose of this study was to assess whether MPO activity is greater in unstable human plaques, how this relates to cardiovascular events and current/emerging non-invasive imaging techniques. Methods: Thirty-one carotid endarterectomy specimens and 12 coronary trees were collected. MPO activity was determined in 88 individual samples through the conversion of hydroethidine to the MPO-specific adduct 2-chloroethidium and compared with macroscopic validation, histology, clinical outcomes, and computed tomography-derived high and low attenuation plaques and perivascular adipose tissue. Non-parametric statistical analysis utilizing Mann-Whitney U and Kruskal-Wallis tests for univariate and group comparisons were performed. Results: Unstable compared with stable plaque had higher MPO activity (carotid endarterectomy: n = 26, 4.2 ± 3.1 vs 0.2 ± 0.3 nmol/mgp; P < 0.0001; coronary: n = 17, 0.6 ± 0.5 vs 0.001 ± 0.003 nmol/mgp; P = 0.0006). Asymptomatic, stroke-free patients had lower MPO activity compared to those with symptoms or ipsilateral stroke (n = 12, 3.7 ± 2.1 vs 0.1 ± 0.2 nmol/mgp; P = 0.002). Computed tomography-determined plaque attenuation did not differentiate MPO activity (n = 30, 0.1 ± 0.1 vs 0.2 ± 0.3 nmol/mgp; P = 0.23) and MPO activity was not found in perivascular adipose tissue. Conclusions: MPO is active within unstable human plaques and correlates with symptomatic carotid disease and stroke, yet current imaging parameters do not identify plaques with active MPO. As intraplaque MPO activity can be imaged non-invasively through novel molecular imaging probes, ongoing investigations into its utility as a diagnostic tool for high-risk atherosclerosis is warranted.

Efficacy of bortezomib, cyclophosphamide and dexamethasone in cardiac AL amyloidosis.

Cardiac light chain (AL) amyloidosis is a condition with a very poor prognosis. We report a retrospective analysis comparing the traditional melphalan and dexamethasone protocol with cyclophosphamide, bortezomib and dexamethasone in late-stage cardiac AL amyloidosis. The primary end points were overall survival and haematological response. Both regimens provided meaningful responses in this difficult to treat patient group.

Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation.

BACKGROUND: Endomyocardial biopsy (EMB) is the gold standard method for surveillance of acute cardiac allograft rejection (ACAR) despite its invasive nature. Cardiovascular magnetic resonance (CMR)-based myocardial tissue characterization allows detection of myocarditis. The feasibility of CMR-based surveillance for ACAR-induced myocarditis in the first year after heart transplantation is currently undescribed. METHODS: CMR-based multiparametric mapping was initially assessed in a prospective cross-sectional fashion to establish agreement between CMR- and EMB-based ACAR and to determine CMR cutoff values between rejection grades. A prospective randomized noninferiority pilot study was then undertaken in adult orthotopic heart transplant recipients who were randomized at 4 weeks after orthotopic heart transplantation to either CMR- or EMB-based rejection surveillance. Clinical end points were assessed at 52 weeks. RESULTS: Four hundred one CMR studies and 354 EMB procedures were performed in 106 participants. Forty heart transplant recipients were randomized. CMR-based multiparametric assessment was highly reproducible and reliable at detecting ACAR (area under the curve, 0.92; sensitivity, 93%; specificity, 92%; negative predictive value, 99%) with greater specificity and negative predictive value than either T1 or T2 parametric CMR mapping alone. High-grade rejection occurred in similar numbers of patients in each randomized group (CMR, n=7; EMB, n=8; P=0.74). Despite similarities in immunosuppression requirements, kidney function, and mortality between groups, the rates of hospitalization (9 of 20 [45%] versus 18 of 20 [90%]; odds ratio, 0.091; P=0.006) and infection (7 of 20 [35%] versus 14 of 20 [70%]; odds ratio, 0.192; P=0,019) were lower in the CMR group. On 15 occasions (6%), patients who were randomized to the CMR arm underwent EMB for clarification or logistic reasons, representing a 94% reduction in the requirement for EMB-based surveillance. CONCLUSIONS: A noninvasive CMR-based surveillance strategy for ACAR in the first year after orthotopic heart transplantation is feasible compared with EMB-based surveillance. REGISTRATION: HREC/13/SVH/66 and HREC/17/SVH/80. AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY: ACTRN12618000672257.

Impact of frailty on mortality and morbidity in bridge to transplant recipients of contemporary durable mechanical circulatory support.

BACKGROUND: Frailty is associated with adverse outcomes in advanced heart failure. We studied the impact of frailty on postoperative outcomes in bridge to transplant (BTT) durable mechanical circulatory support (MCS) recipients. METHODS: Patients undergoing left ventricular assist device (LVAD, n = 96) or biventricular support (BiV, n = 11) as BTT underwent frailty assessment. Frailty was defined as ≥ 3 physical domains of the Fried's Frailty Phenotype (FFP) or ≥ 2 physical domains of the FFP plus cognitive impairment on the Montreal Cognitive Assessment (MoCA). RESULTS: No difference in mortality at 360 days was observed in frail (n = 6/38, 15.8%) vs non-frail (n = 4/58, 6.9%) LVAD supported patients, p = 0.19. However, there was a significant excess mortality in frail BiV (n = 4/5) vs non-frail BiV (n = 0/6) supported patients, p = 0.013. In all patients, frail patients compared to non-frail patients experienced longer intensive care unit stay, 12 vs 6 days (p < 0.0001) and hospital length of stay, 48 vs 27 days (p < 0.0001). There was no difference in hemocompatibility and infection related adverse events. The majority (n = 22/29, 75.9%) of frail patients became non-frail following MCS; contrastingly, a minority (n = 3/42, 7.1%) became frail from being non-frail (p = 0.0003). CONCLUSIONS: Abnormal markers of frailty are common in patients undergoing BTT-MCS support and those used herein predict mortality in BiV-supported patients, but not in LVAD patients. These findings may help us better identify patients who will benefit most from BiV-BTT therapy.