Glycated Haemoglobin Levels and Its Effect on Outcomes in Cardiac Surgery

Abstract There remains a significant paucity of information evaluating the effect of glycated HbA1c levels and its theorized effect on mortality and morbidity rates following cardiac surgery. Diabetes is a very common comorbidity in patients undergoing open heart surgery, as there is a shift in patient characteristics and greater risk. Currently, there is no clear consensus that an increase in HbA1c level is associated with increased perioperative mortality rate. However, the reported literature is more commonly able to demonstrate that elevated HbA1c levels is associated with increased rates of wound infection, cardiovascular events and renal failure, and thus, higher post-operative morbidities. This review aims to examine and synthesis the evidence behind each of the morbidities and mortalities associated with open heart surgery and the impact of high HbA1c on the reported outcomes.

Redo Coronary Artery Bypass Grafting in the era of Advanced PCI

Abstract Objective: To review the evidence behind the role and relevance of redo coronary artery bypass grafting (CABG) in the current practice of percutaneous coronary intervention (PCI). Methods: A comprehensive electronic literature search was performed to identify articles that discuss the practice of PCI and redo CABG in patients that require coronary revascularization. All relevant studies are summarized in narrative manner to reflect current indications and preference. Results: The advancement in utilization of PCI has reduced the rate of redo CABG in patients with previous CABG that requires revascularization of an already treated coronary disease or a new onset of coronary artery stenosis. Redo CABG is associated with satisfactory perioperative outcomes but higher mortality at immediate postoperative period when compared to PCI. Conclusion: Redo CABG patients are less likely to develop comorbidities associated with revascularisation, but the operative mortality is higher and long-term survival rates are similar in comparison to PCI. There is a need for further research into the role of redo CABG in the current advanced practice of PCI.

Transcatheter Aortic Valve Implantation in Bicuspid Aortic Valve with Aortic Stenosis: a Meta-Analysis and Trial Sequential Analysis

Abstract Objectives: Bicuspid aortic valve (BAV) is an important aetiology of aortic stenosis and the use of transcatheter aortic valve implantation (TAVI) has not been fully explored in this cohort. This systematic review and meta-analysis compared the outcomes of TAVI in stenotic BAV against tricuspid aortic valve (TAV). Methods: An electronic literature search was performed in PubMed, MEDLINE, EMBASE, and Scopus to identify all studies comparing TAVI in stenotic BAV versus TAV. Only studies comparing TAVI in BAV versus TAV were included, without any limit on the study date. Primary endpoints were 30-day and 1-year mortality, while secondary endpoints were postoperative rates of stroke, acute kidney injury (AKI), and permanent pacemaker (PPM) requirement. A trial sequential analysis (TSA) was performed for all endpoints to understand their significance. Results: Thirteen studies met the inclusion criteria (917 BAV and 3079 TAV patients). The BAV cohort was younger (76.8±7.43 years vs. 78.5±7.12 years, P=0.02), had a higher trans-aortic valve gradient (P=0.02), and larger ascending aortic diameters (P<0.0001). No significant difference was shown for primary (30-day mortality [P=0.45] and 1-year mortality [P=0.41]) and secondary endpoints (postoperative stroke [P=0.49], AKI [P=0.14], and PPM requirement [P=0.86]). The BAV group had a higher rate of significant postoperative aortic regurgitation (P=0.002). TSA showed that there was sufficient evidence to conclude the lack of difference in PPM requirements, and 30-day and 1-year mortality between the two cohorts. Conclusion: TAVI gives satisfactory outcomes for treating stenotic BAV and should be considered clinically.

The Aortic Pathologies: How Far We Understand It and Its Implications on Thoracic Aortic Surgery

Abstract Thoracic aortic diseases contribute to a major part of cardiac surgeries. The severity of pathologies varies significantly from emergency and life-threatening to conservatively managed conditions. Life-threatening conditions include type A aortic dissection and rupture. Aortic aneurysm is an example of a conservatively managed condition. Pathologies that affect the arterial wall can have a profound impact on the presentation of such cases. Several risk factors have been identified that increase the risk of emergency presentations such as connective tissue disease, hypertension, and vasculitis. The understanding of aortic pathologies is essential to improve management and clinical outcomes.

Permanent Pacemaker Post Cardiac Surgery: where do we Stand?

Abstract Cardiac arrhythmias and requirement for permanent pacemaker (PPM) post open-heart surgery are some of the complications that can contribute to significant morbidities postoperatively and delay in normal recovery if not treated promptly. The reported rate of a PPM following isolated, elective coronary artery bypass grafting is < 1%, while following aortic or mitral valve surgery it is reported to be < 5%. There are several perioperative factors that can contribute to the increased likelihood of PPM requirement including preoperative rhythm, severity and location of cardiac ischaemia, perioperative variables, and the cardiac procedures performed. Optimization of such factors can possibly lead to a lower rate of PPM and, therefore, a lower rate of complications. This literature review focuses on PPM following each procedural type and how to minimize it.

The role of thoracic endovascular aortic repair (tevar) of thoracic aortic diseases in patients with connective tissue disorders - a literature review

Abstract Objective: To review the currently available literature to define the role of thoracic endovascular aortic repair (TEVAR) in patients with connective tissue disorders (CTD). Methods: A comprehensive electronic database search was performed in PubMed, SCOPUS, Embase, Google scholar, and OVID to identify all the articles that reported on outcomes of utilizing TEVAR in patients with CTD during elective and emergency settings. The search was not limited to time or language of the published study. Results: All the relevant studies have been summarized in its correspondence section. The outcomes were analyzed in narrative format. The role of TEVAR has been elaborated as per each study. Currently, there is limited large cohort size studies outlining the use of TEVAR in patients with CTD. The use of endovascular repair in patients with CTD is limited due to progressive aortic dilatations and high possibility of further reinterventions at later stage of life. Conclusion: Open repair remains the gold standard method of intervention in young patients with progressive CTD, especially in the setting of acute type A aortic dissection. However, TEVAR can be sought as a reliable alternative in emergency setting of diseases involving the descending thoracic aorta; yet the long-term data needs to be published to support such practice.

Management of lower limb ischemia during operative repair of acute type a aortic dissection by distal crossover grafts: a case series

Abstract Objective: To describe our experience of nine patients with extra-anatomical bypass for clinically ischemic distal limb during repair of acute Type A aortic dissection (ATAAD). Methods: We retrospectively examined a series of nine patients who underwent surgery for ATAAD. We identified a subset of the patients who presented with concomitant radiographic and clinical signs of lower limb ischemia. All but one patient (axillobifemoral bypass) underwent femorofemoral crossover grafting by the cardiac surgeon during cooling. Results: One hundred eighty-one cases of ATAAD underwent surgery during the study period with a mortality of 19.3%. Nine patients had persistent clinical evidence of lower limb ischemia (4.9%) and underwent extra-anatomical bypass during cooling. Two patients underwent additional fasciotomies. Mean delay from symptoms to surgery in these nine patients was 9.5 hours. Two patients had bilateral amputations despite revascularisation and, of note, had long delays in presentation for surgery (> 12 hours). There were no mortalities during these inpatient episodes. Outpatient radiographic follow-up at the first opportunity demonstrated 100% patency. Conclusion: Our experience suggests that, during complicated aortic dissection, limb ischemia may have a devastating outcome including amputation when diagnosis and referral are delayed. Early diagnosis and surgery are crucial in preventing this potentially devastating complication.

The current management of cardiac tumours: a comprehensive literature review

Abstract Objective: To understand the current evidence and guidelines behind the appropriate management of cardiac tumours. Methods: A comprehensive electronic literature search has been performed in major databases - PubMed, Embase, Scopus, Ovid, and Google Scholar. All articles that discussed all different forms of cardiac tumours, their clinical presentation, diagnosis, and management methods have been critically appraised in this narrative review. Results: All relevant studies have been summarized in appropriate sections within our review. Cardiac tumours are rare but can be catastrophic and life-threatening if not identified and managed on timely manner. Utilization of all the available imaging methods can be of equivocal importance, relevant to each cardiac tumour. Surgical excision is the ultimate treatment method, however histopathological results can guide the adjunct treatment. Conclusion: Early detection of cardiac tumours has significant effect on planning the method of intervention. Technological advancements and increased availability of imaging modalities have enabled earlier and more accurate detection of these tumours. Novel medical therapies, recommendations for screening, and operative techniques have all contributed to overall improving knowledge of these tumours and ultimately patient outcomes.

Which is the optimal frozen elephant trunk? a systematic review and meta-analysis of outcomes in 2161 patients undergoing thoracic aortic aneurysm surgery using e-vita open plus hybrid stent graft versus thoraflex hybrid prosthesis

Abstract Objective: To systematically review the rate of morbidity and mortality associated with the use of E-vita hybrid stent graft and ThoraflexTM in patients undergoing complex aortic surgery. Methods: A comprehensive search was undertaken among the four major databases to identify published data about E-vita or Thoraflex™ in patients undergoing repair of thoracic aortic aneurysms. Results: In total, 28 papers were included in the study, encompassing a total of 2,161 patients (1,919 E-vita and 242 Thoraflex™). Patients undergoing surgery with E-vita or Thoraflex™ were of similar age and sex. The number of patients undergoing non-elective repair with Thoraflex™ was higher than with E-vita (35.2% vs. 28.7%, respectively). Cardiopulmonary bypass time was associated with increasing mortality in E-vita patients, however a meta-analysis of proportions showed higher 30-day mortality, permanent neurological deficit, and one-year mortality for Thoraflex™ patients. Direct statistical comparisons between E-vita and Thoraflex™ was not possible due to heterogeneity of studies. Conclusion: Although there are limited studies available, the available data suggests that mortality and morbidity are lower for the E-vita device in thoracic aortic aneurysm surgery than for Thoraflex™. Long-term data of comparative studies do not yet exist to assess viability of these procedures.

The evolution of mitral valve surgery: the future in the hand of robots

Abstract Objective: To examine the current literature behind the evolution of mitral valve surgery techniques and their impact on patient outcomes. Methods: An electronic literature search among major databases was performed (PubMed, Embase, Scopus, Cochrane, and Google scholar). All the relevant articles were screened and identified to be included in this narrative review. The main outcomes were postoperative morbidity, length of in-hospital stay, and long-term mortality. Results: Minimally invasive and robot-assisted approach to mitral valve repair and replacements has shown great potential in improving surgical outcomes when compared against traditional midline sternotomy. Selected patients can benefit from percutaneous mitral valve surgery; however, more evidence is required to ascertain its long-term outcomes. Conclusion: Current evidence suggests that robotic and minimal invasive mitral valve surgeries are increasing in practice with satisfactory perioperative and mortality rates. However, long-term data is yet to be published to support current practice.

Surgical treatment of atrial fibrillation: cutting through the edges

Abstract Medical management of atrial fibrillation can be complex, challenging and requiring time to prove its effectiveness; furthermore, the response can be refractory and inconsistent if the underlying pathology is not permanently addressed. Surgical ablation has become a key intervention, and since its first intervention in 1987 (the Cox-maze procedure), the technique has evolved from a conventional open method to a minimally invasive technique whilst retaining excellent outcomes. Furthermore, recent advances in the use of a hybrid approach have been established as satisfactory approach in managing atrial fibrillation with satisfactory outcomes. This literature review focuses on the evidence behind the surgical success in managing atrial fibrillation throughout the past, present and the future of these surgical interventions.

Thoracic aortic aneurysm surgery in marfan patients: a perspective from the uk

Abstract Objective: Cardiovascular complications in Marfan patients include progressive aortic root dilation which can precipitate acute aortic dissection, ruptured aorta, severe aortic regurgitation, or all the aforementioned. Such complications can be fatal and the cause of death prior to any surgical intervention. We set out to identify the Marfan population in England and Wales and present their surgical outcomes. Methods: A total of 306 patients with Marfan syndrome who underwent aortic root surgery were identified between April 2007 and March 2013 from NICOR database. We examined the perioperative characteristics of such cohort along with in-hospital outcomes and survival. Results: Root and ascending segment procedures on Marfan patients performed in 3.3% of the total cohort by NICOR root surgery patients. The median reported age was 40 years (IQR = 29-49 years) and 100 (32.7%) were female. Of the patients analysed, 17.3% were treated non-electively and 68.6% of them received concomitant valve procedure. The in-hospital mortality was 2.0%. Reoperation for bleeding was required in 8.2% of patients and 1.3% of them suffered a cerebrovascular accident (CVA). Mortality at 1 year was reported as 5.5%. Conclusion: The outcomes of surgery on the root and ascending aorta in Marfan patients in the United Kingdom are satisfactory; however, the overall complexities of this patient population are not well understood and would benefit from further investigations.

Should doctors know their patients' attachment style? a psychological perspective and its impact on cardiac surgery outcomes

Abstract Objective: To increase our understanding of the psychological attachment styles in order to develop a preventative strategy that could potentially improve patients' perioperative outcomes. Methods: A comprehensive literature search was performed utilizing major electronic databases. The search was done from inception to January 2019. All of the relevant papers have been extracted and critically appraised in this review. Results: Understanding the psychological aspects of patients is crucial for a satisfactory postoperative outcome. Depression and anxiety have been shown to increase both mortality and morbidity after coronary artery bypass graft surgery, independently of medical factors, although the behavioural and biological mechanisms are poorly understood. Psychosocial assessment is an important part of the pre-transplant evaluation process. The majority of individuals undergoing a transplant have significant psychosocial problems and can either be deferred or denied the transplant until these psychosocial issues are approached and managed. Psychological distress has been shown to affect long-term prognosis of cardiac patients and as a result, it should be addressed during follow-up of cardiac arrest survivors due to cardiac cause. Several studies have considered different approaches and analyses of different psychological attachments, and the understanding of such parameters perioperatively could possibly minimise perioperatively complications. Conclusion: Since psychological distress affects long-term prognosis of cardiac surgery patients, it should be addressed during follow-up of cardiac arrest survivors due to cardiac cause.

Acute kidney injury associated with cardiac surgery: a comprehensive literature review

Abstract Objective: To comprehensively understand cardiac surgeryassociated acute kidney injury (CSA-AKI) and methods of prevention of such complication in cardiac surgery patients. Methods: A comprehensive literature search was performed using the electronic database to identify articles describing acute kidney injury (AKI) in patients that undergone cardiac surgery. There was neither time limit nor language limit on the search. The results were narratively summarized. Results: All the relevant articles have been extracted; results have been summarized in each related section. CSA-AKI is a serious postoperative complication and it can contribute to a significant increase in perioperative morbidity and mortality rates. Optimization of factors that can reduce CSA-AKI, therefore, contributes to a better postoperative outcome. Conclusion: Several factors can significantly increase the rate of AKI; identification and minimization of such factors can lead to lower rates of CSA-AKI and lower perioperative morbidity and mortality rates.

Bioprosthetic aortic valve replacement in <50 years old patients - where is the evidence?

Abstract Aortic valve disease is one of the most common valvular heart diseases in the cardiovascular category. Surgical replacement of the diseased aortic valve remains the definitive intervention for most diseases. There is a clear consensus that in young patients who require aortic valve replacement, a mechanical prosthesis is the preferred choice due to its durable prosthesis without fear of wear and tear over time. However, this comes at the expense of increased risk of bleeding and thromboembolic events; in addition, there is a lack of strict evidence in using bioprosthesis in patients younger than 50 years. The objective of this review article is to assess the current evidence behind using bioprosthetic aortic valve in this young cohort.

Could cerebrospinal fluid biomarkers offer better predictive value for spinal cord ischaemia than current neuromonitoring techniques during thoracoabdominal aortic aneurysm repair - a systematic review

Abstract Objective: Cerebrospinal fluid (CSF) drainage is a technique that has significantly reduced the incidence of spinal cord ischaemia (SCI). We present results of a systematic review to assess the literature on this topic in relation to thoracoabdominal aortic aneurysm repair (TAAR). Methods: Major medical databases were searched to identify papers related to CSF biomarkers measured during TAAAR. Results: Fifteen papers reported measurements of CSF biomarkers with 265 patients in total. CSF biomarkers measured included S-100ß, neuron-specific endolase (NSE), lactate, glial fibrillary acidic protein A (GFPa), Tau, heat shock protein 70 and 27 (HSP70, HSP27), and proinflammatory cytokines. Lactate and S-100ß were reported the most, but did not correlate with SCI, which was also the case with NSE and TAU. GFPa showed significant CSF level rises, both intra and postoperative in patients who suffered SCI and warrants further investigation, similar results were seen with HSP70, HSP27 and IL-8. Conclusions: Although there is significant interest in this topic, there still remains a significant lack of high-quality studies investigating CSF biomarkers during TAAR to detect SCI. A large and multicentre study is required to identify the significant role of each biomarker.

Innominate vs. axillary artery cannulation in aortic surgery: a systematic review and meta-analysis

Abstract Objective: To investigate whether axillary artery cannulation has supremacy over innominate artery cannulation in thoracic aortic surgery. Methods: A comprehensive search was undertaken among the four major databases (PubMed, Excerpta Medica dataBASE [EMBASE], Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing axillary to innominate artery cannulation in thoracic aortic surgery. Databases were evaluated and assessed up to March 2017. Results: Only three studies fulfilled the criteria for this meta-analysis, including 534 patients. Cardiopulmonary bypass time was significantly shorter in the innominate group (P=0.004). However, the innominate group had significantly higher risk of prolonged intubation > 48 hours (P=0.04) than the axillary group. Further analysis revealed no significant difference between the innominate and axillary groups for deep hypothermic circulatory arrest time (P=0.06). The relative risks for temporary and permanent neurological deficits as well as in-hospital mortality were not significantly different for both groups (P=0.90, P=0.49, and P=0.55, respectively). Length of hospital stay was similar for both groups. Conclusion: There is no superiority of axillary over innominate artery cannulation in thoracic aortic surgery in terms of perioperative outcomes; however, as the studies were limited, larger scale comparative studies are required to provide a solid evidence base for choosing optimal arterial cannulation site.