COVID-19 safety: aerosol-generating procedures and cardiothoracic surgery and anaesthesia - Australian and New Zealand consensus statement.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is a contagious disease that is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Health care workers are at risk of infection from aerosolisation of respiratory secretions, droplet and contact spread. There are a number of procedures that represent a high risk of aerosol generation during cardiothoracic surgery. It is important that adequate training, equipment and procedures are in place to reduce that risk. RECOMMENDATIONS: We provide a number of key recommendations, which reduce the risk of aerosol generation during cardiothoracic surgery and help protect patients and staff. These include general measures such as patient risk stratification, appropriate use of personal protective equipment, consideration to delay surgery in positive patients, and careful attention to theatre planning and preparation. There are also recommended procedural interventions during airway management, transoesophageal echocardiography, cardiopulmonary bypass, chest drain management and specific cardiothoracic surgical procedures. Controversies exist regarding the management of low risk patients undergoing procedures at high risk of aerosol generation, and recommendations for these patients will change depending on the regional prevalence, risk of community transmission and the potential for asymptomatic patients attending for these procedures. CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT: This statement reflects changes in management based on expert opinion, national guidelines and available evidence. Our knowledge with regard to COVID-19 continues to evolve and with this, guidance may change and develop. Our colleagues are urged to follow national guidelines and institutional recommendations regarding best practices to protect their patients and themselves. ENDORSED BY: Australian and New Zealand Society of Cardiac and Thoracic Surgeons and the Anaesthetic Continuing Education Cardiac Thoracic Vascular and Perfusion Special Interest Group.

Mitral valve repair rates in degenerative mitral valve disease correlate with surgeon and hospital procedural volume.

STUDY AIM: To determine the relationship between surgeon and hospital procedural volume, and mitral valve repair rates and 30-day mortality for degenerative mitral regurgitation (MR), in Australian cardiac surgical centers. METHODS: A total of 4420 patients who underwent elective surgery for degenerative MR between January 2008 and December 2017 in the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database were retrospectively included. Univariate and multivariate regression analyses examined surgeon and hospital procedural volumes for associations with repair rate and mortality. RESULTS: Repair rates varied widely by caseload; from 62.57% to 79.53% for lowest to highest volume surgeons; and from 54.56% to 77.54% for lowest to highest volume hospitals. Compared to surgeons performing ≤5 procedures/annum, surgeons performing 10.1-20/annum were more likely to repair the valve (odds ratio [OR] 2.40, 95% confidence interval [CI] 1.09-5.28, p = .03), particularly if performing more than 20/annum (OR 2.88, 95% CI 1.09-7.60, p = .03). Compared to hospitals performing ≤10/annum, those performing any number of procedures more than 10 demonstrated an increased likelihood of repair (caseload 10.1-20/year OR 1.96, 95% CI 1.25-3.07, p = .003) though odds did not increase above this threshold. Low incidence of 30-day mortality (63 of 4414, 1.43%) limited analysis of contributing variables; procedural volume did not confer a survival benefit. CONCLUSIONS: Surgeon and hospital caseload were significantly associated with repair rates of degenerative MR. A threshold minimum of 10 procedures annually for surgeons and hospitals should be utilized to maximize repair rates, and ideally of 20 for surgeons. Mortality was low and may not be significantly impacted by procedural volume.

2021 CSANZ and ANZSCTS Position Statement on the Operator and Institutional Requirements for a Transcatheter Aortic Valve Implantation (TAVI) Program in Australia.

This document establishes the minimum standard for accreditation of institutions and operators as endorsed by the Cardiac Society of Australia and New Zealand (CSANZ) and the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS). The original Joint Society Position Statement was ratified in August 2014. This 2021 update replaces the original and serves as a consensus within which the Conjoint Committee for Trancatheter Aortic Valve Implantation (TAVI) Accreditation will function, as recommended by Medical Services Advisory Committee (MSAC) Determination for TAVI. This is not a Guideline Statement but takes into consideration regional, legislative, and health system factors important to establishing requirements for TAVI accreditation in Australia.

Predictors of Pacemaker Insertion Post-Sutureless (Perceval) Aortic Valve Implantation.

INTRODUCTION: The use of rapid deployment sutureless aortic valve replacement (AVR) has become a viable alternative to conventional AVR especially in intermediate and high-risk patients. However, sutureless AVR has been associated with increased rates of permanent pacemaker (PPM) implantation compared with conventionally implanted aortic valve prostheses. The aim of this study was to determine predictive factors for complete heart block requiring insertion of a PPM post-AVR with a Perceval S sutureless valve (LivaNova, London, UK). Such knowledge will help to improve patient counselling, selection and management of patients undergoing sutureless AVR. METHODOLOGY: A retrospective cohort study assessed all patients who underwent insertion of the Perceval sutureless aortic valve prosthesis between July 2015 and September 2019. Medical records were reviewed for demographic, preoperative electrocardiograph (ECG), and operative features related to postoperative PPM implantation and follow-up in the electrophysiology clinic. RESULTS: One hundred and thirty (130) patients without pre-existing PPM underwent sutureless AVR (66.9% male, average age 74.4±6.6 years). Fifty-seven (57) underwent concomitant cardiac surgical procedures. Eight (8) patients underwent redo cardiac surgery. Nineteen (19) of the 130 (14.6%) patients required insertion of a PPM during their postoperative course. Factors associated with PPM insertion were right bundle branch block (overall n=15, PPM vs No PPM: 8/19 vs 7/111 [42.1 % vs. 6.31 %; p<0.01]), longer QRS duration 113.32ms±22.24 ms vs 100.52±20.96 ms (p=0.017) and longer PR Interval 185.166±42.38 ms vs 169.23±25.70 ms (p=0.03). CONCLUSION: Insertion of rapid deployment sutureless aortic valves in the setting of pre-existing right bundle branch block, prolonged QRS complex and longer PR intervals is associated with increased risk of postoperative PPM requirement. These factors should be considered when preoperatively counselling and postoperatively managing patients when balloon expandable sutureless valves are used.

Operator and Institutional Requirements for Transcatheter Mitral Valve Therapies in Australia: a CSANZ and ANZSCTS Position Statement.

This expert Position Statement is a description of the requirements for Accreditation for transcatheter mitral valve therapy (TMVT) in Australia. The requirements include the need for a multidisciplinary Heart Team review of individual cases, mandatory reporting of outcome data to a national TMVT Registry, and accreditation of individuals and institutions by the Conjoint Accreditation Committee, the assigned accreditation authority.

Cardiovascular disease and COVID-19: Australian and New Zealand consensus statement.

INTRODUCTION: The coronavirus 2019 disease (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pre-existing cardiovascular disease (CVD) increases the morbidity and mortality of COVID-19, and COVID-19 itself causes serious cardiac sequelae. Strategies to minimise the risk of viral transmission to health care workers and uninfected cardiac patients while prioritising high quality cardiac care are urgently needed. We conducted a rapid literature appraisal and review of key documents identified by the Cardiac Society of Australia and New Zealand Board and Council members, the Australian and New Zealand Society of Cardiac and Thoracic Surgeons, and key cardiology, surgical and public health opinion leaders. MAIN RECOMMENDATIONS: Common acute cardiac manifestations of COVID-19 include left ventricular dysfunction, heart failure, arrhythmias and acute coronary syndromes. The presence of underlying CVD confers a five- to tenfold higher case fatality rate with COVID-19 disease. Special precautions are needed to avoid viral transmission to this population at risk. Adaptive health care delivery models and resource allocation are required throughout the health care system to address this need. CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT: Cardiovascular health services and cardiovascular health care providers need to recognise the increased risk of COVID-19 among CVD patients, upskill in the management of COVID-19 cardiac manifestations, and reorganise and innovate in service delivery models to meet demands. This consensus statement, endorsed by the Cardiac Society of Australia and New Zealand, the Australian and New Zealand Society of Cardiac and Thoracic Surgeons, the National Heart Foundation of Australia and the High Blood Pressure Research Council of Australia summarises important issues and proposes practical approaches to cardiovascular health care delivery to patients with and without SARS-CoV-2 infection.

The Use of a Preoperative Mitral Valve Model to Guide Mitral Valve Repair.

BACKGROUND: Mitral valve repair is commonly used to address degenerative or functional changes to the mitral valve apparatus and surrounding ventricular anatomy. Preoperative transoesophageal echocardiogram (TOE) is routinely used to evaluate and identify the precise anatomic location of mitral valve pathology in order to guide repair. However, surgeons currently lack specific guidance regarding the approximate dimensions of the mitral valve they should aim for in order to achieve optimal valve function and avoid adverse outcomes. Therefore, through an observational study, we aimed to develop and test the accuracy of a preliminary mathematical model which represents the geometric relationship between various clinically relevant components of the mitral valve and its surrounding structures. METHODS: Using established trigonometric principles, the geometric relationship shared between several mitral valve components was represented in a two-dimensional (2D) model and described in a mathematical equation. The output variable of the model is the anteroposterior diameter of the mitral valve. To assess the accuracy of the mathematical model, we compared the model-predicted anteroposterior (AP) diameter against AP diameter measured by postoperative TOE in 42 cases. RESULTS: The root mean squared error (RMSE) of model predicted AP diameter compared to measured AP diameter was 0.43 cm. The mean absolute percentage error (MAPE) of the model was 17.7%. In 34 out of 42 cases, model-predicted AP diameters were within 25% of AP diameters measured by postoperative TOE. CONCLUSIONS: Preliminary testing of a simple mathematical model has shown its relative accuracy in representing the geometric relationship between several mitral valve variables. Further research and refinement of the model is required in order to improve its accuracy. We are encouraged that, with further improvement, the model has the potential for clinical application.

Early Outcomes of Sutureless Aortic Valve Replacement With the Perceval S Bioprosthesis.

BACKGROUND: Sutureless aortic valve replacement (SU-AVR) offers an alternative to traditional aortic valve replacement (AVR) and is becoming widely performed in many hospitals. The aim of the current study was to evaluate the early experience in SU-AVR with the Perceval S bioprosthesis at Monash Medical Centre. METHODS: Fifty-two (52) patients who underwent SU-AVR were retrospectively analysed (mean age: 74.8±6.5years). Data regarding preoperative and operative details, hospital stay, postoperative outcomes within 30days after surgery, re-admissions and longer term echocardiographic data were collected from the relevant hospital databases. RESULTS: In isolated SU-AVR, the mean aortic cross-clamp and cardiopulmonary bypass times were 48.8 and 67.8minutes, respectively. There were no deaths within 30days after surgery. Rhythm disturbances developed in 46.2% of patients, with atrial fibrillation (32.7%) and heart block (9.6%) being most common. Mean and peak transaortic gradients reduced from 46.2 and 77.9mmHg preoperatively, to 10.7 and 19.7mmHg at 12 months postoperatively, respectively. CONCLUSIONS: The absence of early mortality and the satisfactory clinical and haemodynamic results demonstrated the overall safety and efficacy of the Perceval S valve. Although sutureless valves seem to be a promising alternative to traditional sutured valves, the high rate of new postoperative rhythm disturbances, particularly heart block, is potentially a concern with SU-AVR.

Stenting of the Brachiocephalic Vein Following Occlusion After Coronary Artery Bypass Surgery.

We describe a case of left arm swelling over nine months post coronary artery bypass grafting (CABG), due to occlusion of the left brachiocephalic vein. The patient's perioperative course, diagnosis, and management of this complication are presented. doi: 10.1111/jocs.12765 (J Card Surg 2016;31:432-434).

Tranexamic Acid in cardiac surgery and postoperative seizures: a case report series.

With the recent withdrawal of the antifibrinolytic aprotinin from the market, tranexamic acid (TxA) has become more widely used. This change has led to increasing concern about the side-effect profile of TxA, particularly the incidence of postoperative seizures. In this case series, we describe 7 patients over an 18-month period who had open-chamber cardiac surgery and developed seizures in the postoperative period. This incidence is increased compared with that of a cohort of patients in the previous 36 months who did not receive TxA (0.66% versus 0%; P < .05). The exact mechanism of TxA-induced seizures is thought to be via inhibition of gamma-aminobutyric acid receptors in neurons. Data from the neurosurgical literature show a well-established link between this antifibrinolytic and seizures. There is now increasing awareness of this association in cardiac surgery, particularly when high TxA doses are used.

A cost-analysis study of robotic versus conventional mitral valve repair.

BACKGROUND: Robotic mitral valve repair has been performed in Australia since 2004. The aim of this study was to perform a cost-analysis of robotic mitral valve repair (MVR) with direct comparison to conventional MVR surgery. METHODS: All isolated MVRs performed within one metropolitan hospital network, between June 2005 and June 2008, were retrospectively compared. Ad hoc cost analysis was conducted. RESULTS: There were 107 robotic and 40 conventional MVRs performed. The post-operative degrees of mitral regurgitation were comparable. Total operating time was 18% longer in robotic compared to conventional (239 min vs. 202 min, p<0.001, 95% CI: 11-27%). In robotic, Intensive Care Unit stay was reduced by 19% (p=0.002, 37 h vs. 45 h), and length of hospital stay was reduced by 26% (p<0.001, 6.47 days vs. 8.76 days). Mean hospital cost, without including capital costs, was not significantly increased (AUD$18,503 vs. AUD$17,880 p=0.176, 95% CI: -282 to 1,530). CONCLUSIONS: Robotic mitral repair can be performed with similar immediate repair success rates as conventional surgery with a shorter recovery time, but a slightly longer operative time. There is no significant increase in cost over conventional surgery.

First-in-Human Chronic Implant Experience of the Substernal Extravascular Implantable Cardioverter-Defibrillator.

OBJECTIVES: The aim of this study was to evaluate the safety and performance of an extravascular (EV) implantable cardioverter-defibrillator (ICD). BACKGROUND: Limitations of existing transvenous and subcutaneous ICD systems include lead reliability and morbidity issues associated with ICD lead implantation in the vasculature or lack of pacing therapies (e.g., antitachycardia pacing) in subcutaneous systems. The EV defibrillator uses a novel substernal lead placement to address these limitations. METHODS: This was a prospective, nonrandomized, chronic pilot study conducted at 4 centers in Australia and New Zealand. Participants were 21 patients referred for ICD implantation. Patients received EV ICD systems. Data collection included major systemic and procedural adverse events, defibrillation testing at implantation, and sensing and pacing thresholds. RESULTS: Among 20 patients who underwent successful implantation, the median defibrillation threshold was 15 J, and 90% passed defibrillation testing with a ≥10-J safety margin. Mean R-wave amplitude was 3.4 ± 2.0 mV, mean ventricular fibrillation amplitude was 2.8 ± 1.7 mV, and pacing was successful in 95% at ≤10 V. There were no intraprocedural complications. Two patients have undergone elective chronic system removal since hospital discharge. In the 15 patients presently implanted, the systems are stable in long-term follow-up. CONCLUSIONS: This first-in-human evaluation of an EV ICD demonstrated the feasibility of substernal lead placement, defibrillation, and pacing with a chronically implanted system. There were no acute major complications, and pacing, defibrillation, and sensing performance at implantation were successful in most patients. (Extravascular ICD Pilot Study [EV ICD]; NCT03608670).

Echocardiographic measurement of mitral intertrigonal distance is an adjunct to annuloplasty ring sizing.

BACKGROUND AND AIM OF THE STUDY: Annuloplasty sizing with standard valve sizers may be imprecise and difficult in minimally invasive procedures. It is hypothesized that a constant clinical conversion factor relates the echocardiographic aortic annulus diameter (AAD) and the intertrigonal distance (ITD) in patients with degenerative mitral regurgitation (MR). This may provide another method to size the annuloplasty ring required for mitral valve repair. METHODS: An observational study of 50 patients with degenerative MR undergoing robotic-assisted surgery was conducted. All patients underwent surgery between September 2005 and November 2007. The AAD at the base of the aortic leaflets was measured using intraoperative two-dimensional transesophageal echocardiography. The ITD was measured independently under direct vision during surgery. The echocardiographic ITD was then determined by dividing the AAD by 0.8, and the value for each patient compared to the corresponding surgical measurement. Agreement was assessed statistically using the Bland-Altman method. RESULTS: The limits of agreement were -3 mm (t = 2.010; 49 df; p = 0.05; 95% CI: -4 to -2 mm) to 3 mm (t = 2.010; 49 df; p = 0.05; 95% CI: 2 to 4 mm). In 86% of cases (43/50), the differences between the two methods was < or = 2 mm. CONCLUSION: In most cases of degenerative mitral valve disease the echocardiographic ITD measurement is clinically acceptable, and may serve as an adjunct to existing methods when sizing the annuloplasty ring required for repair.

Epicardial high-intensity focused ultrasound cardiac ablation for surgical treatment of atrial fibrillation.

BACKGROUND: The available alternatives to an effective but technically complex Cox maze procedure for surgical treatment of atrial fibrillation include ablation using radiofrequency, microwave, laser, cryotherapy or ultrasound energy sources. The purpose of this study was to evaluate the safety and efficacy profile of high-intensity focused ultrasound cardiac ablation for the surgical treatment of atrial fibrillation. METHODS: 14 patients underwent epicardial high-intensity focused ultrasound treatment for atrial fibrillation using the Epicor cardiac ablation system between August 2006 and August 2007. The procedure was performed on the beating heart prior to the commencement of cardiopulmonary bypass for concomitant cardiac procedures. Physical examination, electrocardiography and 24-h Holter monitoring were used to determine the postoperative heart rhythm. RESULTS: There were no deaths directly related to the procedure. One patient with myelodysplastic syndrome died of septic complications. Three patients required cardioversion at 1 day, 3- and 4-month intervals postoperatively. The mean follow-up period was 9 months. Currently 10/13 (77%) patients are in sinus rhythm, one patient required insertion of a permanent pacemaker, one patient is in atrial fibrillation and another patient is in atrial flutter. CONCLUSION: Epicardial high-intensity focused ultrasound ablation is a viable alternative to the Cox maze procedure for the surgical treatment of atrial fibrillation. It is a safe and efficient procedure that does not require cardiopulmonary bypass and may potentially be performed using less invasive surgical techniques.

Early Experience With New Transcatheter Mitral Valve Replacement.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a potential therapy for patients with symptomatic, severe mitral regurgitation (MR). The feasibility of this therapy remains to be defined. OBJECTIVES: The authors report their early experience with TMVR using a new valve system. METHODS: The valve is a self-expanding, nitinol valve with bovine pericardial leaflets that is placed using a transapical delivery system. Patients with symptomatic MR who were deemed high or extreme risk by the local heart teams were enrolled in a global pilot study at 14 sites (United States, Australia, and Europe). RESULTS: Fifty consecutively enrolled patients (mean age: 73 ± 9 years; 58.0% men; 84% secondary MR) underwent TMVR with the valve. The mean Society for Thoracic Surgery score was 6.4 ± 5.5%; 86% of patients were New York Heart Association functional class III or IV, and the mean left ventricular ejection fraction was 43 ± 12%. Device implant was successful in 48 patients with a median deployment time of 14 min (interquartile range: 12 to 17 min). The 30-day mortality was 14%, with no disabling strokes, or repeat interventions. Median follow-up was 173 days (interquartile range: 54 to 342 days). At latest follow-up, echocardiography confirmed mild or no residual MR in all patients who received implants. Improvements in symptom class (79% in New York Heart Association functional class I or II at follow-up; p < 0.0001 vs. baseline) and Minnesota Heart Failure Questionnaire scores (56.2 ± 26.8 vs. 31.7 ± 22.1; p = 0.011) were observed. CONCLUSIONS: TMVR with the valve was feasible in a study group at high or extreme risk for conventional mitral valve replacement. These results inform trial design of TMVR in lower-risk patients with severe mitral valve regurgitation (Evaluation of the Safety and Performance of the Twelve Intrepid Transcatheter Mitral Valve Replacement System in High Risk Patients with Severe, Symptomatic Mitral Regurgitation - The Twelve Intrepid TMVR Pilot Study; NCT02322840).

Urgent and emergency coronary artery bypass grafting for acute coronary syndromes.

BACKGROUND: Urgent and emergency coronary artery bypass grafting may be associated with significant mortality and morbidity. We report our recent experience with this group of patients. METHODS: A retrospective analysis of 441 patients undergoing urgent and emergency surgery over a 3-year period was carried out. Multivariate analysis was used to identify subgroups of patients who were most at risk of death. RESULTS: The 30-day mortality was 3.3 and 16.3% in the urgent and emergency groups, respectively. Urgent surgery was associated with significantly shorter duration of ventilation (16 h vs 69 h) and stay at the intensive care unit (31 h vs 102 h). The incidence of pneumonia, pulmonary embolism, renal failure and neurological events were also less in the urgent group. The preoperative use of the intra-aortic balloon pump was low (0.8% in the urgent group and 4.8% in the emergency group). Multivariate analysis showed that patients over 70 years of age (odds ratio 3.2, 95% confidence interval 1.1-9.5) with left main stenosis (odds ratio 4.4, 95% confidence interval 1.5-12.4) complicated by cardiogenic shock (odds ratio 17.8, 95% confidence interval 5.2-61.1) were at highest risk of death. Patients transferred directly to theatre from cardiac catheter laboratory following failed percutaneous interventions were found to be most at risk. Mortality in this group was 29%, with 50% patients being in shock and 36% having left main stenosis. CONCLUSION: Satisfactory results have been obtained in urgent coronary artery bypass grafting, but acute coronary syndromes complicated by cardiogenic shock remain a high-risk group. Further studies are needed to define the optimal operative management in this group of patients.

Experience with unipolar radiofrequency ablation for atrial fibrillation.

BACKGROUND: The cut and sew Cox maze procedure for atrial fibrillation (AF), although effective, is not widely used because of technical complexity, prolonged duration and significant risk of postoperative bleeding. This study reviews our experience with the unipolar radiofrequency ablation (RFA) procedure, which was used to create a modified maze to treat AF. METHODS: A retrospective review of 31 patients undergoing consecutive cardiac surgery who had concomitant RFA for AF over a 16-month period was carried out. A Cobra unipolar RFA probe (EPT; Boston Scientific, San Jose, CA, USA) was used to create a standard set of lesions. RESULTS: There were 20 men and 11 women (mean age, 66 +/- 9 years; range, 48-87 years). AF was continuous in 21 patients and intermittent in 10. The median duration of AF leading up to surgery was 48 months (range, 6 months-20 years). Left atrium was enlarged in 81% of the patients. Operations included mitral valve repair (7 patients), replacement (5), coronary artery bypass (10), aortic valve replacement (1) and combined procedures (8). There were no complications directly attributable to RFA. There were three early deaths. One patient required a permanent pacemaker. Median follow up was 22 months (range, 12-30 months). One patient died 2 years after the operation from a stroke. Cardioversion was attempted in five patients within 3 months of operation and was successful in four. At 2 years following the procedure, the probability of the patient remaining in sinus rhythm was 0.71 +/- 0.15. CONCLUSION: Surgical RFA can be carried out as a useful adjunct to conventional cardiac surgery. Although the results were satisfactory in this series, further studies are needed to refine the indication of the procedure and to assess its longer-term efficacy.