A Novel Porcine Model of Bilateral Hindlimb Bypass Graft Surgery Integrating Transit Time Flowmetry.

Background: Bypass graft surgery is a key surgical intervention for ischemic heart disease (coronary bypass graft surgery) and critical limb ischemia (peripheral bypass graft surgery). Graft occlusion remains a significant clinical problem for both types. Further research into the pathobiological mechanisms of graft occlusion are needed in order to design targeted therapeutic strategies.

Interventional Strategies for Children with Progressive Pulmonary Hypertension Despite Optimal Therapy. An Official American Thoracic Society Clinical Practice Guideline.

Background: Pulmonary hypertension in children often progresses despite optimal therapy. This document provides an evidence-based clinical practice guideline for the management of children with progressive pulmonary hypertension despite optimal therapy.

Methods: A multidisciplinary panel identified pertinent questions regarding the management of children with pulmonary hypertension that has progressed despite optimal therapy, conducted systematic reviews of the relevant literature, and applied the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to develop clinical recommendations.

Limitations of the inotrope score use as a measure of primary graft dysfunction.

Allograft dysfunction is the major cause of early morbidity and mortality following cardiac transplantation. Poor graft function can be secondary to transplant complications or, when no identifiable cause is present, primary graft dysfunction (PGD). To standardize the definition of PGD, a consensus conference was convened which produced a document that defines severity categories and criteria for assessing left and right ventricular dysfunction.

Will blood-informed design signal the fourth generation of cardiac assist devices?

Mechanical circulatory support devices have profoundly transformed the management of severe cardiothoracic disorders. While heart transplantation is the gold standard therapy for end-stage heart disease, long-term mechanical support devices are a viable alternative for those ineligible and/or those awaiting organ availability. Major technological advancements were made over first 5 decades of development, resulting in improved durability and survival with reduced adverse events.

Echocardiographic surrogate of left ventricular stroke work in a model of brain stem death donors.

Background: The commonest echocardiographic measurement, left ventricular ejection fraction, can not necessarily predict mortality of recipients following heart transplantation potentially due to afterload dependency. Afterload-independent left ventricular stroke work index (LVSWI) is alternatively recommended by the current guideline; however, pulmonary artery catheters are rarely inserted in organ donors in most jurisdictions. We propose a novel non-invasive echocardiographic parameter, Pressure-Strain Product (PSP), as a potential surrogate of catheter-based LVSWI.

HeartMate 3 implantation with an emphasis on the biventricular configuration.

Objectives: Right ventricular failure following implantation of a durable left ventricular assist device (LVAD) is a major driver of mortality. Reported survival following biventricular (BiVAD) or total artificial heart (TAH) implantation remains substantially inferior to LVAD alone. We report our outcomes with LVAD and BiVAD HeartMate 3 (HM3).

Impact of postoperative hyperlactatemia in orthotopic heart transplantation.

Background: Hyperlactatemia (HL) is a common phenomenon after cardiac surgery which is related to tissue hypoperfusion and hypoxia and associated with poor outcomes. It is also often seen in the postoperative period after orthotopic heart transplantation (OHTx), but the association between HL and outcomes after OHTx is not well known. We evaluated the incidence and outcome of HL after OHTx.

Hypothermic oxygenated perfusion (HOPE) safely and effectively extends acceptable donor heart preservation times: Results of the Australian and New Zealand trial.

Background: Cold static storage preservation of donor hearts for periods longer than 4 hours increases the risk of primary graft dysfunction (PGD). The aim of the study was to determine if hypothermic oxygenated perfusion (HOPE) could safely prolong the preservation time of donor hearts.

Methods: We conducted a nonrandomized, single arm, multicenter investigation of the effect of HOPE using the XVIVO Heart Preservation System on donor hearts with a projected preservation time of 6 to 8 hours on 30-day recipient survival and allograft function post-transplant.

Donor heart ischemic time can be extended beyond 9 hours using hypothermic machine perfusion in sheep.

Background: The global shortage of donor hearts available for transplantation is a major problem for the treatment of end-stage heart failure. The ischemic time for donor hearts using traditional preservation by standard static cold storage (SCS) is limited to approximately 4 hours, beyond which the risk for primary graft dysfunction (PGD) significantly increases. Hypothermic machine perfusion (HMP) of donor hearts has been proposed to safely extend ischemic time without increasing the risk of PGD.

Heart-Lung Transplantation: Technical Modifications to Simplify the Procedure.

Heart-lung transplantation is a mature therapy but has perioperative complications, such as phrenic nerve dysfunction and mediastinal bleeding. We report our technical modifications to simplify the procedure.

Extracorporeal Membrane Oxygenation as a Bridge to Surgical Repair of Postinfarct Ventricular Septal Defect.

Postinfarct ventricular septal defect (PIVSD) is associated with high mortality and the management of these patients has been a challenge with little improvement in outcomes. We commenced a protocol of veno-arterial extracorporeal membrane oxygenation (VA ECMO) for those patients who present in cardiogenic shock with the aim to improve end-organ function before definitive surgical repair to reduce postoperative mortality. This study reviewed the results of this strategy.

A clinically relevant sheep model of orthotopic heart transplantation 24 h after donor brainstem death.

Background: Heart transplantation (HTx) from brainstem dead (BSD) donors is the gold-standard therapy for severe/end-stage cardiac disease, but is limited by a global donor heart shortage. Consequently, innovative solutions to increase donor heart availability and utilisation are rapidly expanding. Clinically relevant preclinical models are essential for evaluating interventions for human translation, yet few exist that accurately mimic all key HTx components, incorporating injuries beginning in the donor, through to the recipient.

Mitral Valve Regurgitation After Lung Transplantation: Aetiology, Management and Outcome.

Background: Problematic mitral regurgitation (MR) may develop following lung transplantation (LTx). There is limited information on the management of MR in LTx patients, as such we sought to evaluate our centre's experience.

Methods: From 2000 to 2019, 1,054 patients underwent LTx at our centre (896 bilateral, 158 single).

The frequent insignificance of a "significant" p-value.

Null hypothesis significance testing (NHST) and p-values are widespread in the cardiac surgical literature but are frequently misunderstood and misused. The purpose of the review is to discuss major disadvantages of p-values and suggest alternatives. We describe diagnostic tests, the prosecutor's fallacy in the courtroom, and NHST, which involve inter-related conditional probabilities, to help clarify the meaning of p-values, and discuss the enormous sampling variability, or unreliability, of p-values.

An Intention-to-treat View of Lung Transplantation for Interstitial Lung Disease: Successful Strategies to Minimize Waiting List and Posttransplant Mortality.

Background: Access to lung transplantation (LTx) and rates of waiting list and posttransplant mortality for patients with interstitial lung disease (ILD) remain problematic. We evaluated the outcomes of ILD patients listed for LTx at our institution.

Methods: Between 2012 and 2018, adult patients with ILD were listed and transplanted from a donor-pool that included extended criteria and donation after circulatory-determined death donors.

Compromised right ventricular contractility in an ovine model of heart transplantation following 24 h donor brain stem death.

Background: Heart failure is an inexorably progressive disease with a high mortality, for which heart transplantation (HTx) remains the gold standard treatment. Currently, donor hearts are primarily derived from patients following brain stem death (BSD). BSD causes activation of the sympathetic nervous system, increases endothelin levels, and triggers significant inflammation that together with potential myocardial injury associated with the transplant procedure, may affect contractility of the donor heart.

Heart Transplantation From Brain Dead Donors: A Systematic Review of Animal Models.

Despite advances in mechanical circulatory devices and pharmacologic therapies, heart transplantation (HTx) is the definitive and most effective therapy for an important proportion of qualifying patients with end-stage heart failure. However, the demand for donor hearts significantly outweighs the supply. Hearts are sourced from donors following brain death, which exposes donor hearts to substantial pathophysiological perturbations that can influence heart transplant success and recipient survival.

A donor PaO/FiO < 300 mm Hg does not determine graft function or survival after lung transplantation.

Background: A donor arterial PO/FiO (P/F ratio) of less than the 300 threshold would frequently result in either exclusion of the donor or placement of the lungs on ex vivo lung perfusion (EVLP). The aim was to investigate the veracity of the P/F ratio threshold of 300 for donor lung acceptability.

Methods: In 93 brain dead lung donors, arterial blood gases were drawn in the intensive care unit (ICU) just before procurement and each of the 4 donor pulmonary veins in the operating room (OR).