Outcomes in Dialysis-Dependent Indigenous and Non-Indigenous Patients Undergoing Cardiac Surgery at Townsville University Hospital.

PURPOSE: Dialysis-dependent patients have a high risk of cardiovascular death but also a high risk for perioperative mortality in cardiac surgery. Our study examined surgical complications and mortality in Indigenous and non-Indigenous dialysis-dependent patients undergoing cardiac surgery at a single centre. METHODOLOGY: The retrospective study reviewed 72 consecutive dialysis-dependent patients who underwent cardiac surgery between 2008 and 2018. Data was prospectively collected, and follow-up was obtained from physicians and general practitioners. Multivariable analysis was performed to determine predictors of mortality. RESULTS: The median age of Indigenous Australian patients was 60 years, compared with 65 years for non-Indigenous patients. Indigenous Australian patients had a significantly higher rate of return to theatre (43% versus 17%). The predominant reason for return to theatre for the whole cohort was postoperative bleeding (n=16, 22%). The overall early mortality rate was 10%. There were 35 late deaths (49%) and overall survival at 5 years was 40.92±6.8% (95% CI: 28-54%). History of arrhythmia (p=0.019) was a significant risk factor for mortality, whilst patients who underwent isolated coronary artery bypass grafting (p=0.004), and those who received internal mammary artery grafts (p=0.021) had a reduced hazard ratio for mortality. The median follow-up time was 29 months (IQR 10-52 mo). CONCLUSION: Dialysis-dependent Indigenous Australian patients present younger for cardiac surgery, with a higher prevalence of co-morbid diabetes and more extensive coronary artery disease. There was no statistically significant difference in early or late mortality between Indigenous and non-Indigenous patients. However, there was a higher rate of return to theatre amongst the Indigenous Australian cohort.

Cardiology, Research and Training: An Interview With Professor Eugene Braunwald.

Professor Eugene Braunwald, often referred to as the 'Father of Modern Cardiology', has contributed significantly to medicine and cardiology. He is best known for the acclaimed textbook Braunwald's Heart Disease and for being the founding chairman of the Thrombolysis in Myocardial Infarction (TIMI) Study Group. Our primary aim is to highlight his experiences and the guidance that he has to offer to future generations of medical trainees and professionals. An interview with Prof. Braunwald provided the authors with an insight into his journey in medicine. A range of questions were posed pertaining to his struggles and accomplishments in cardiology, his perspectives on the future of cardiology and research, as well as his advice to current and future medical professionals.1 Positive role models are an inspiration to all, regardless of the stage in their career. With hard work, unwavering dedication and a strong desire to make a positive difference to patients and the field, the opportunities are endless. Whether it is clinical or bench research, advances in clinical cardiology and research usually go hand-in-hand. Although primary and secondary prevention of cardiovascular disease remain of critical importance, it is now time to focus on primordial prevention to step back and reduce the development of the risk factors for the future development of cardiovascular disease in the first place. There have been significant advances in cardiology over the past two-thirds of the century during which Prof. Braunwald trained and then led the field. However, there is still much work to be done. Mentors and medical institutions alike must work towards a common goal of 'igniting the fire' within the new generation of clinicians and investigators who will then propel this important specialty to ever greater heights.

Recurrent Bioprosthetic Valve Thrombosis - Should Long-Term Anticoagulation Be Considered?

Bioprosthetic valve thrombosis (BPVT) is an important and potentially reversible cause of valvular dysfunction. This complication can occur many years after surgery and understanding of the precise mechanisms and risk factors is limited. Anticoagulation therapy has been demonstrated to be effective in improving BPVT. However, the optimal duration of therapy and the risk of recurrence are unknown. Herein, we describe two cases-one of late BPVT and one of recurrence of BPVT after cessation of anticoagulation therapy.

Donor Lung Procurement by Surgical Fellow With an Expectation of High Rate of Lung Utilisation.

There is an ever increasing demand for donor lungs in patients waiting for transplantation. Lungs of many potential donors will be rejected if the standard criteria for donor assessment are followed. We have expanded our donor lung pool by accepting marginal donors and establishing a donation after circulatory death program. We have achieved comparable results using marginal donors and accepting donor lungs following donation after circulatory death. We present our assessment and technical guidelines on lung procurement taking into consideration an increasingly complex cohort of lung donors. These guidelines form the basis of the lung procurement training program involving surgical Fellows at the Alfred Hospital in Melbourne, Australia.

Pulmonary Artery Reconstruction with Donor Aortic Homograft During Cardiac Transplantation in the Failed Fontan Circulation.

The advanced surgical management of patients with single ventricle physiology, in particular the hypoplastic left heart syndrome, has resulted in an increased number of patients with a Fontan circulation. In a proportion of these patients, the Fontan circulation will ultimately fail and cardiac transplantation may be required. Their course may be complicated by the hemodynamic consequences of the failing Fontan, multiple previous operations, and the frequent need for complex reconstruction at transplantation. We describe a patient with a failed modified Fontan circulation requiring concomitant pulmonary artery reconstruction and cardiac transplantation and review potential reconstruction techniques.

Management of a Left Internal Thoracic Artery Graft Injury during Left Thoracotomy for Thoracic Surgery.

There have been some recent reports on the surgical treatment of lung cancer in patients following previous coronary artery bypass graft surgery. Use of internal thoracic artery graft is a gold standard in cardiac surgery with superior long-term patency. Left internal thoracic artery graft is usually patent during left lung resection in patients who present to the surgeon with an operable lung cancer. We have presented our institutional experience with left-sided thoracic surgery in patients who have had previous coronary artery surgery with a patent internal thoracic artery graft.

Successful Bridge to Orthotopic Cardiac Transplantation with Implantation of a HeartWare HVAD in Management of Systemic Right Ventricular Failure in a Patient with Transposition of the Great Arteries and Previous Atrial Switch Procedure.

A clinical case is described of a patient with a history of dextro-transposition of the great arteries (d-TGA) and prior atrial switch procedure who developed significant pulmonary hypertension whilst awaiting orthotopic cardiac transplantation. The increase in his pulmonary pressures necessitated de-listing for cardiac transplantation. A strategy of ventricular assist device (VAD) placement was then employed which provided improvement in his systemic cardiac output with left atrial off-loading to provide pulmonary vascular remodelling and consequently reduction in pulmonary vascular resistance (PVR). He was supported for a period of 408 days prior to successful orthotopic cardiac transplantation. A small number of cases with this abnormality undergoing VAD implantation have been described. Mechanical circulatory support has an important role in some patients with congenital heart disease.

Pericardial Synovial Sarcoma: A Rare Clinical Entity.

Synovial sarcoma is an extremely rare form of primary malignancy of the pericardium. We present a case of primary synovial sarcoma of the pericardium followed by a review of the literature.

Left Ventricular Assist Device (LVAD) as a Bridge to Recovery for Tachycardia-Mediated Cardiomyopathy.

A case is described of cardiogenic shock that occurred following use of sotalol in a patient with severe left ventricular dysfunction. The patient required left ventricular assist device (LVAD) placement with subsequent myocardial recovery to a degree that allowed eventual device removal following 140 days of support.

Impaired relaxation despite upregulated calcium-handling protein atrial myocardium from type 2 diabetic patients with preserved ejection fraction.

BACKGROUND: Diastolic dysfunction is a key factor in the development and pathology of cardiac dysfunction in diabetes, however the exact underlying mechanism remains unknown, especially in humans. We aimed to measure contraction, relaxation, expression of calcium-handling proteins and fibrosis in myocardium of diabetic patients with preserved systolic function. METHODS: Right atrial appendages from patients with type 2 diabetes mellitus (DM, n = 20) and non-diabetic patients (non-DM, n = 36), all with preserved ejection fraction and undergoing coronary artery bypass grafting (CABG), were collected. From appendages, small cardiac muscles, trabeculae, were isolated to measure basal and ß-adrenergic stimulated myocardial function. Expression levels of calcium-handling proteins, sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) and phospholamban (PLB), and of ß1-adrenoreceptors were determined in tissue samples by Western blot. Collagen deposition was determined by picro-sirius red staining. RESULTS: In trabeculae from diabetic samples, contractile function was preserved, but relaxation was prolonged (Tau: 74 ± 13 ms vs. 93 ± 16 ms, non-DM vs. DM, p = 0.03). The expression of SERCA2a was increased in diabetic myocardial tissue (0.75 ± 0.09 vs. 1.23 ± 0.15, non-DM vs. DM, p = 0.007), whereas its endogenous inhibitor PLB was reduced (2.21 ± 0.45 vs. 0.42 ± 0.11, non-DM vs. DM, p = 0.01). Collagen deposition was increased in diabetic samples. Moreover, trabeculae from diabetic patients were unresponsive to ß-adrenergic stimulation, despite no change in ß1-adrenoreceptor expression levels. CONCLUSIONS: Human type 2 diabetic atrial myocardium showed increased fibrosis without systolic dysfunction but with impaired relaxation, especially during ß-adrenergic challenge. Interestingly, changes in calcium-handling protein expression suggests accelerated active calcium re-uptake, thus improved relaxation, indicating a compensatory calcium-handling mechanism in diabetes in an attempt to maintain diastolic function at rest despite impaired relaxation in the diabetic fibrotic atrial myocardium. Our study addresses important aspects of the underlying mechanisms of diabetes-associated diastolic dysfunction, which is crucial to developing new therapeutic treatments.

Rapid onset of cardiomyopathy in STZ-induced female diabetic mice involves the downregulation of pro-survival Pim-1.

BACKGROUND: Diabetic women are five times more likely to develop congestive heart failure compared with two fold for men. The underlying mechanism for this gender difference is not known. Here we investigate the molecular mechanisms responsible for this female disadvantage and attempt safeguarding cardiomyocytes viability and function through restoration of pro-survival Pim-1. METHODS AND RESULTS: Diabetes was induced by injection of streptozotocin in CD1 mice of both genders. Functional and dimensional parameters measurement using echocardiography revealed diastolic dysfunction in female diabetic mice within 8 weeks after STZ-induced diabetes. This was associated with significant downregulation of pro-survival Pim-1 and upregulation of pro-apoptotic Caspase-3, microRNA-1 and microRNA-208a. Male diabetic mice did not show any significant changes at this time point (P < 0.05 vs. female diabetic). Further, the onset of ventricular remodelling was quicker in female diabetic mice showing marked left ventricular dilation, reduced ejection fraction and poor contractility (P < 0.05 vs. male diabetic at 12 and 16 weeks of STZ-induced diabetes). Molecular analysis of samples from human diabetic hearts confirmed the results of pre-clinical studies, showing marked downregulation of Pim-1 in the female diabetic heart (P < 0.05 vs. male diabetic). Finally, in vitro restoration of Pim-1 reversed the female disadvantage in diabetic cardiomyocytes. CONCLUSIONS: We provide novel insights into the molecular mechanisms behind the rapid onset of cardiomyopathy in female diabetics. These results suggest the requirement for the development of gender-specific treatments for diabetic cardiomyopathy.

Procurement of lungs for transplantation following donation after circulatory death: the Alfred technique.

INTRODUCTION: Donation after circulatory death (DCD) is an evolving method for lung transplantation (LTx) with results comparable to donation after brain death (DBD). MATERIALS AND METHODS: DCD lung transplant program requires a systematic approach for an efficient utilization of hospital resources. The surgical techniques have been developed to minimize the ischemic time during lung procurement. We have presented our management protocol and the surgical techniques as used at the Alfred Hospital in Melbourne, Australia. RESULTS: We have transplanted 92 recipients with lungs procured from 91 donors over an 8 year period from May 2006 to July 2014. This accounted for an extra 19% lung transplant operations performed during this time period. Operative mortality was 1% and 8 year survival was 71% in DCD lung recipients. CONCLUSIONS: DCD lung transplantation provides an additional significant pool of lung donors with satisfactory short and long term outcomes.

The role of remote ischemic preconditioning in organ protection after cardiac surgery: a meta-analysis.

BACKGROUND: Remote ischemic preconditioning (RIPC) appears to protect distant organs from ischemia-reperfusion injury. We undertook meta-analysis of clinical studies to evaluate the effects of RIPC on organ protection and clinical outcomes in patients undergoing cardiac surgery. METHODS: A review of evidence for cardiac, renal, and pulmonary protection after RIPC was performed. We also did meta-regressions on RIPC variables, such as duration of ischemia, cuff pressure, and timing of application of preconditioning. Secondary outcomes included length of hospital and intensive care unit stay, duration of mechanical ventilation, and mortality at 30 days. RESULTS: Randomized control trials (n = 25) were included in the study for quantitative analysis of cardiac (n = 16), renal (n = 6), and pulmonary (n = 3) protection. RIPC provided statistically significant cardiac protection (standardized mean difference [SMD], -0.77; 95% confidence interval [CI], -1.15, -0.39; Z = 3.98; P < 0.0001) and on subgroup analysis, the protective effect remained consistent for all types of cardiac surgical procedures. However, there was no evidence of renal protection (SMD, 0.74; 95% CI, 0.53, 1.02; Z = 1.81; P = 0.07) or pulmonary protection (SMD, -0.03; 95% CI, -0.56, 0.50; Z = 0.12; P = 0.91). There was no statistical difference in the short-term clinical outcomes between the RIPC and control groups. CONCLUSIONS: RIPC provides cardiac protection, but there is no evidence of renal or pulmonary protection in patients undergoing cardiac surgery using cardiopulmonary bypass. Larger multicenter trials are required to define the role of RIPC in surgical practice.

Laminectomy retractor: a useful tool for redo sternotomy.

Sternal re-entry represents a critical step during redo cardiac surgery. We describe a simple method that relies on opening of the posterior table of the sternum with a laminectomy retractor after dividing the anterior table with an oscillating saw.

3D echocardiography in cardiac surgery.

Herein, we present a patient who underwent successful repair of failed mitral valve repair in whom intraoperative 3D transesophageal echocardiography provided accurate assessment of the mechanism of mitral regurgitation. In addition, we review the potential advantages and limitations of 3D echocardiography and its role in cardiac surgery.