Publications by authors named "Andrew Jabbour"

Article Synopsis
  • - This study investigates which models of vascular afterload best predict right-sided heart dysfunction in patients with newly diagnosed pulmonary hypertension (PH), focusing on factors like pulmonary vascular resistance (PVR) and pulmonary arterial compliance (PAC).
  • - Researchers analyzed data from 86 patients using right-sided heart catheterization and cardiac magnetic resonance imaging, revealing that PVR was the most accurate predictor for several measures of heart dysfunction, except when PVR was low, where PAC showed better predictive power.
  • - A combined model using PVR, PAC, and characteristic impedance provided the best prediction for right atrial volume changes, and a specific PAC threshold (<2.3 mL/mm Hg) was identified as a strong predictor for right-sided heart dysfunction in
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Article Synopsis
  • Transthyretin amyloidosis with cardiomyopathy (ATTR-CM) is a serious, progressive disease, and vutrisiran is a new treatment that works by reducing the production of transthyretin in the liver.
  • In a double-blind trial involving 655 patients, those receiving vutrisiran had a lower risk of death and cardiovascular events compared to those on placebo, demonstrating significant efficacy.
  • Vutrisiran also improved patient outcomes, showing less decline in walking distance and quality of life measurements over the study period compared to placebo.
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Background: Coronary allograft vasculopathy (CAV) remains a significant cause of morbidity and mortality after heart transplantation. The use of aspirin for CAV prophylaxis has recently garnered interest as a possible therapeutic adjunct in this setting.

Methods: This 2-center retrospective cohort study included 372 patients who underwent heart transplantation between January 2009 and March 2018 and were stratified according to the commencement of aspirin during their index transplant admission.

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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.

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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 rabbits ( = 12) using the MPO-gadolinium (Gd) probe at 8 and 12 weeks after induction of atherosclerosis and before pharmacological triggering of atherothrombosis.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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There are limited data on post-transplant lymphoproliferative disorder (PTLD) in the era of positron emission tomography (PET) and rituximab (R). Furthermore, there is limited data on the risk of graft rejection with modern practices in reduction in immunosuppression (RIS). We studied 91 patients with monomorphic diffuse large B-cell lymphoma PTLD at 11 Australian centers: median age 52 years, diagnosed between 2004 and 2017, median follow-up 4.

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The increasing prevalence of patients with aortic stenosis worldwide highlights a clinical need for improved and accurate prediction of clinical outcomes following surgery. We investigated patient demographic and cardiovascular magnetic resonance (CMR) characteristics to formulate a dedicated risk score estimating long-term survival following surgery. We recruited consecutive patients undergoing CMR with gadolinium administration prior to surgical aortic valve replacement from 2003 to 2016 in two UK centres.

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