Impella CP is a percutaneously inserted left ventricular assist device indicated for temporary mechanical cardiac support during high risk percutaneous coronary interventions and for cardiogenic shock. The potential application of Impella has become particularly relevant during the current COVID-19 pandemic, for patients with acute severe heart failure complicating viral illness. Standard implantation of the Impella CP is performed under fluoroscopic guidance. Positioning of the Impella CP can be confirmed with transthoracic or transoesophageal echocardiography. We describe an alternative approach to guide intracardiac implantation of the Impella CP using two-dimensional and three-dimensional intracardiac echocardiography. This new technique can be useful in selected groups of patients when fluoroscopy, transthoracic and transoesophageal echocardiography is deemed inapplicable or limited for epidemiological or clinical reasons. Intracardiac three-dimensional echocardiography is a feasible alternative to the traditional techniques for implantation of an Impella CP device but careful consideration must be given to the potential limitations and complications of this technique.
Radial Artery versus Bilateral Mammary Composite Y Coronary Artery Grafting: 15-year Outcomes
Background: Total arterial coronary revascularization for three vessel disease can be achieved with a second arterial conduit joined to the left internal mammary artery as a Y graft, using either a radial artery (RAY) or second mammary artery (BIMAY).
Methods: Patients receiving total arterial revascularization for three coronary territory disease were identified from two cardiac surgical databases (Sydney and Melbourne) using Society of Thoracic Surgeons-based definitions. BIMAY patients underwent surgery between 1994 and 2009, mostly using an age-limited protocol, while RAY patients underwent surgery between 1996 and 2003 without age limits. All-cause mortality was acquired from the national death registry and survival estimated by the Kaplan-Meier method. Propensity score matching was performed using 13 variables. Due to the age imbalance between groups, the primary comparison was performed for age ≤66 years.
Results: Overall, 1,896 patients received RAY and 720 patients received BIMAY. Older age at surgery was the strongest independent predictor for mortality with a hazard ratio of HR 2.06, 95%CI 1.93, 2.22, P<0.001. After propensity score matching, we identified 299 pairs of patients ≤66 years with no preoperative or operative differences and similar age at surgery, RAY 56.4±7.0 vs. BIMAY 56.4±6.8 years, P=0.96. The RAY group had 4.0±0.9 grafts and the BIMAY group had 3.9±0.9, P=0.814. All-cause mortality was not different, with the proportion surviving at 15 years at 74.9% for RAY vs. 76.2% for BIMAY (P=0.211).
Conclusions: Survival was not different between RAY and BIMAY for total arterial revascularization of three coronary territory bypass grafting.
Mini-access branch-first total arch replacement and frozen elephant trunk procedure
Minimally-invasive surgery presents its own unique set of challenges, especially when applied to treatment of aortic arch disease. The key components of mini-access aortic arch surgery include safe circulatory control, adequate organ protection, and meticulous surgical technique. This article describes how to perform branch-first total arch replacement with the frozen elephant trunk (FET) procedure for distal arch aneurysms. The strategy employed offers the advantages of mini-access surgery, as well as sound cerebral and systemic organ protection strategies.
Comparison of dynamic changes in stressed intravascular volume, mean systemic filling pressure and cardiovascular compliance: Pilot investigation and study protocol.
The mean systemic filling pressure (MSFP) represents an interaction between intravascular volume and global cardiovascular compliance (GCC). Intravascular volume expansion using fluid resuscitation is the most frequent intervention in intensive care and emergency medicine for patients in shock and with haemodynamic compromise. The relationship between dynamic changes in MSFP, GCC and left ventricular compliance is unknown. We conducted prospective interventional pilot study following euthanasia in post cardiotomy adult sheep, investigating the relationships between changes in MSFP induced by rapid intravascular filling with fluids, global cardiovascular compliance and left ventricular compliance. This pilot investigation suggested a robust correlation between a gradual increase in the intravascular stressed volume from 0 to 40 ml/kg and the MSFP r = 0.708 95% CI 0.435 to 0.862, making feasible future prospective interventional studies. Based on the statistical modelling from the pilot results, we expect to identify a strong correlation of 0.71 ± 0.1 (95% CI) between the MSFP and the stressed intravascular volume in a future study.
Novel Oral Anticoagulants Compared to Warfarin for Postoperative Atrial Fibrillation After Isolated Coronary Artery Bypass Grafting
Background: Postoperative atrial fibrillation (POAF) is common after cardiac surgery and contributes to short- and long-term morbidity, particularly thromboembolism. Anticoagulation for sustained or recurrent POAF is suggested to reduce thromboembolism. Novel oral anticoagulants may present a safe alternative to warfarin with further benefits including shorter hospital length of stay and better patient convenience.
Methods: A retrospective analysis was performed on all isolated cases of coronary artery surgery (CABG) at our institution between January 2015 and December 2018, totalling 960 patients. Rates of POAF were examined with particular focus on preoperative factors, postoperative outcomes, and anticoagulation practices.
Results: The incidence of POAF was 31.8% (305 patients) and was higher in older patients (67.6±9.4 yrs vs 63.0±10.7 yrs, p<0.001), those with a history of cerebrovascular disease (14.6% vs 8.7%, p=0.02), those with higher CHADS-VASc scores (2.5±1.3 vs 2.8±1.3, p<0.001) those who had a postoperative return to theatre (2.6% vs 0.8%, p=0.002), and those with new renal failure (4.9% vs 1.8%, p=0.02). Off-pump surgery was associated with lower incidence of POAF (29.8% vs 37.1%, p=0.03). Patients who developed POAF had significantly longer admissions than those without (12.6±10.6 days vs 9.3±16.3 days, p<0.001). In total, 106 patients (11.0%) went home anticoagulated; 77 (72.6%) on warfarin and 29 (27.4% on a NOAC). Readmission for bleeding was higher in patients on anticoagulation (1.0% vs 0.0%, p=0.02), but did not drive readmission for pericardial effusion (0.3% vs 0.6%, p=0.55). No bleeding complications occurred in patients who were discharged on a NOAC. Overall mortality at median of 2 years was 1.8% (17 patients) and no mortality occurred in any patient discharged on anticoagulation.
Conclusion: Postoperative atrial fibrillation is a common adverse event and is linked to higher preoperative and postoperative morbidity. Anticoagulation may be safely started in these patients and use of novel anticoagulation does not appear to increase postoperative complications, although overall numbers are low.
Rural and Remote Cardiology During the COVID-19 Pandemic: Cardiac Society of Australia and New Zealand (CSANZ) Consensus Statement
The challenges: Rural and remote Australians and New Zealanders have a higher rate of adverse outcomes due to acute myocardial infarction, driven by many factors. The prevalence of cardiovascular disease (CVD) is also higher in regional and remote populations, and people with known CVD have increased morbidity and mortality from coronavirus disease 2019 (COVID-19). In addition, COVID-19 is associated with serious cardiac manifestations, potentially placing additional demand on limited regional services at a time of diminished visiting metropolitan support with restricted travel. Inter-hospital transfer is currently challenging as receiving centres enact pandemic protocols, creating potential delays, and cardiovascular resources are diverted to increasing intensive care unit (ICU) and emergency department (ED) capacity. Regional and rural centres have limited staff resources, placing cardiac services at risk in the event of staff infection or quarantine during the pandemic.
Main recommendations: Health districts, cardiologists and government agencies need to minimise impacts on the already vulnerable cardiovascular health of regional and remote Australians and New Zealanders throughout the COVID-19 pandemic. Changes in management should include.
Evaluation of aortic stenosis using cardiovascular magnetic resonance: a systematic review & meta-analysis
Background: As the average age of patients with severe aortic stenosis (AS) who receive procedural intervention continue to age, the need for non-invasive modalities that provide accurate diagnosis and operative planning is increasingly important. Advances in cardiovascular magnetic resonance (CMR) over the past two decades mean it is able to provide haemodynamic data at the aortic valve, along with high fidelity anatomical imaging.
Methods: Electronic databases were searched for studies comparing CMR to transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE) in the diagnosis of AS. Studies were included only if direct comparison was made on matched patients, and if diagnosis was primarily through measurement of aortic valve area (AVA).
Results: Twenty-three relevant, prospective articles were included in the meta-analysis, totalling 1040 individual patients. There was no significant difference in AVA measured as by CMR compared to TEE. CMR measurements of AVA size were larger compared to TTE by an average of 10.7% (absolute difference: + 0.14cm2, 95% CI 0.07-0.21, p < 0.001). Reliability was high for both inter- and intra-observer measurements (0.03cm2 +/- 0.04 and 0.02cm2 +/- 0.01, respectively).
Conclusions: Our analysis demonstrates the equivalence of AVA measurements using CMR compared to those obtained using TEE. CMR demonstrated a small but significantly larger AVA than TTE. However, this can be attributed to known errors in derivation of left ventricular outflow tract size as measured by TTE. By offering additional anatomical assessment, CMR is warranted as a primary tool in the assessment and workup of patients with severe AS who are candidates for surgical or transcatheter intervention.
Evolving experience of operating theatre staff with the implementation of robotic-assisted surgery in the public sector
Objectives The use of robotic-assisted surgery (RAS) remains predominantly in the private sector. In the public sector, the effect of the implementation of RAS on theatre staff is unknown. The aim of this study was to examine the knowledge and attitudes of theatre staff before and after implementation of RAS in the public sector. Methods In all, 250 theatre staff, including nursing, medical and support staff, were invited to participate in the study. A survey investigating the benefits of RAS for patients and staff, concerns towards the workplace environment and facilitators towards the implementation of new technology was administered before (June 2016) and after (February 2019) the implementation of a comprehensive RAS program. Results The survey was completed by 164 (65.6%) staff before and 200 (80.0%) staff after the implementation of RAS. With time, most nursing (P=0.002) and medical staff (P=0.003) indicated that RAS may benefit patients by reducing intraoperative complications, whereas support staff remained uncertain about this benefit (P=0.594). Before the implementation, most medical staff indicated that RAS would benefit staff, although after they were unsure about this benefit. Overall, before RAS implementation, theatre staff were mostly concerned about workplace safety, but this concern was significantly reduced after RAS implementation (P<0.010). Conclusions With time, operating theatre staff considered their RAS program to be associated with enhanced benefits to patients, and their concerns regarding workplace safety were significantly reduced. Conversely, theatre staff were unsure about the benefits of RAS to themselves. It is important for organisations to consider the evolving impact of new technology on their staff and to refine ongoing education and training programs in line with these changes. What is known about the topic? The implementation of RAS is rapidly evolving in major hospitals. Therefore, it is important to investigate the knowledge, attitudes and experiences of operating theatre staff before and after the implementation of RAS, especially in the public sector. What does this paper add? This study found that with time theatre staff considered RAS to be beneficial to patients, and their initial concerns about the effect on workplace safety were significantly reduced. What are the implications for practitioners? It is important for organisations to consider the evolving impact of the implementation of new technology on operating theatre staff and to refine ongoing education and training programs as required.
Three-dimensional intracardiac echocardiography and pulmonary embolism
Background: Three-dimensional intracardiac echocardiography (3D ICE) with wide azimuthal elevation is a novel technique performed for assessment of cardiac anatomy and guidance of intracardiac procedures, being able to provide unique views with good spatial and temporal resolution. Complications arising from this invasive procedure and the value of 3D ICE in the detection and diagnosis of acute cardiovascular pathology are not comprehensively described. This case illustrates a previously unreported iatrogenic complication of clot displacement from the intra-vascular sheath upon insertion of a 3D ICE catheter and the value of 3D ICE in immediate diagnosis of clot in transit through the heart with pulmonary embolism.
Case presentation: We conducted a translational study of 3D ICE with wide azimuthal elevation to guide implantation of a left ventricular assist device (Impella CP®) in eight adult sheep. A large-bore 14 Fr central venous sheath was used to enable right atrial and right ventricular access for the intracardiac catheter. Insertion of the 3D ICE catheter was accompanied by a sudden severe cardiorespiratory deterioration in one animal. 3D ICE revealed a large highly mobile mass within the right heart chambers, determined to be a clot-in-transit. The diagnosis of pulmonary clot embolism resulting from the retrograde blood entry into the large-bore sheath introducer, rapid clot formation and consequent displacement into venous circulation by the ICE catheter was made. The sheep survived this life-threatening event following institution of cardiovascular support allowing completion of the primary research protocol.
Conclusion: This report serves as a serious warning to the researchers and clinicians utilizing long large-bore sheath introducers for 3D ICE and illustrates the value of 3D ICE in detecting clot-in-transit within right heart chambers.
COVID-19 and Acute Heart Failure: Screening the Critically Ill – A Position Statement of the Cardiac Society of Australia and New Zealand (CSANZ)
Up to one-third of COVID-19 patients admitted to intensive care develop an acute cardiomyopathy, which may represent myocarditis or stress cardiomyopathy. Further, while mortality in older patients with COVID-19 appears related to multi-organ failure complicating acute respiratory distress syndrome (ARDS), the cause of death in younger patients may be related to acute heart failure. Cardiac involvement needs to be considered early on in critically ill COVID-19 patients, and even after the acute respiratory phase is passing. This Statement presents a screening algorithm to better identify COVID-19 patients at risk for severe heart failure and circulatory collapse, while balancing the need to protect health care workers and preserve personal protective equipment (PPE). The significance of serum troponin levels and the role of telemetry and targeted transthoracic echocardiography (TTE) in patient investigation and management are addressed, as are fundamental considerations in the management of acute heart failure in COVID-19 patients
