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The expansion in the repertoire of genes linked to thoracic aortic aneurysms (TAA) has revolutionised our understanding of the disease process. The clinical benefits of such progress are numerous, particularly helping our understanding of non-syndromic hereditary causes of TAA (HTAAD) and further refinement in the subclassification of disease. Furthermore, the understanding of aortic biomechanics and mechanical homeostasis has been significantly informed by the discovery of deleterious mutations and their effect on aortic phenotype. The drawbacks in genetic testing in TAA lie with the inability to translate genotype to accurate prognostication in the risk of thoracic aortic dissection (TAD), which is a life-threatening condition. Under current guidelines, there are no metrics by which those at risk for dissection with normal aortic diameters may undergo preventive surgery. Future research lies with more advanced genetic diagnosis of HTAAD and investigation of the diverse pathways involved in its pathophysiology, which will i) serve to improve our understanding of the underlying mechanisms, ii) improve guidelines for treatment and iii) prevent complications for HTAAD and sporadic aortopathies.

This study aims to identify the clinical utility of targeted-genetic sequencing in a cohort of patients with TAA and establish a new method for regional histological characterisation of TAA disease.Fifty-four patients undergoing surgery for proximal TAA were recruited.connective tissue disease, bicuspid aortic valves, redo surgery. All patients underwent next generation sequencing (NGS) using a custom gene panel containing 63 genes previously associated with TAA on Illumina MiSeqor NextSeq550 platforms. Explanted TAA tissue was obtained en-bloc from 34/54 patients, and complete circumferential strips of TAA tissue processed into whole slides which were subsequently digitalised. Computational pathology methods were employed to quantify elastin, cellularity and collagen in six equally divided regions across the whole aneurysm circumference.Of 54 patients, clearly pathogenic or potentially pathogenic variants were found in 7.4%: namely LOX, PRKG1, TGFBR1 and SMAD3 genes. 55% had at least one variant of unknown significance (VUS) and seven of the VUSs were in genes with a strong disease association (category A) genes, whilst 15 were from moderate risk (category B) genes. Elastin and collagen abundance displayed high regional variation throughout the aneurysm circumference. In patients with60% total elastin, the loss of elastin was more significant on the outer curve (38.0% vs 47.4%, p = 0.0094). The presence of VUS, higher pulse wave velocity and advancing age were predictors of elastin loss (regression analysis: p 0.05).These findings demonstrate the heterogeneity of TAA disease microstructure and the potential link between histological appearance and clinical factors, including genetic variation.

INTRODUCTION: Postoperative acute kidney injury (AKI) and the requirement for renal replacement therapy (RRT) remain common and significant complications of both transcatheter valve-in-valve aortic valve replacement (ViV-TAVR) and redo surgical aortic valve replacement (SAVR). Nevertheless, the understanding of renal outcomes in the population undergoing either redo SAVR or ViV-TAVR remains controversial. METHODS: A systematic database search with meta-analysis was conducted of comparative original articles of ViV-TAVR versus redo SAVR in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to September 2021. Primary outcomes were AKI and RRT. Secondary outcomes were stroke, major bleeding, pacemaker implantation rate, operative mortality, and 30-day mortality. RESULTS: Our search yielded 5435 relevant studies. Eighteen studies met the inclusion criteria with a total of 11,198 patients. We found ViV-TAVR to be associated with lower rates of AKI, postoperative RRT, major bleeding, pacemaker implantation, operative mortality, and 30-day mortality. No significant difference was observed in terms of stroke rate. The mean incidence of AKI in ViV-TAVR was 6.95% (±6%) and in redo SAVR was 15.2% (±9.6%). For RRT, our data showed that VIV-TAVR to be 1.48% (±1.46%) and redo SAVR to be 8.54% (±8.06%). CONCLUSION: Renoprotective strategies should be put into place to prevent and reduce AKI incidence regardless of the treatment modality. Patients undergoing re-intervention for the aortic valve constitute a high-risk and frail population in which ViV-TAVR demonstrated it might be a feasible option for carefully selected patients. Long-term follow-up data and randomized control trials will be needed to evaluate mortality and morbidity outcomes between these 2 treatments.

INTRODUCTION: Cardiac surgery involving cardiopulmonary bypass (CPB) activates an inflammatory response releasing cytokines that are associated with less favourable outcomes. This study aims to compare i) CPB during cardiac surgery (control) versus ii) CPB with haemoadsorption therapy; and assess the effect of adding this therapy in reducing the inflammatory cytokines burden. METHODS: A systematic literature review with meta-analysis was conducted regarding the main outcomes (operative mortality, ventilation duration, intensive care unit [ICU] and hospital stays) and day-1 inflammatory markers levels post-surgery. Fifteen (15) studies were included for final analysis (eight randomised controlled trials, seven observational studies) with no evidence of publication bias. RESULTS: Subgroup analysis of non-elective surgeries across observational studies (emergency and infective endocarditis) significantly favoured cytokine filters in terms of 30-day mortality (OR 0.40, 95% CI 0.20, 0.83; p=0.01) and shorter ICU stay (MD -42.36, 95% CI -68.07, -16.65; p=0.001). At day-1 post-surgery, there was a significant difference favouring the cytokine filter group in c-reactive protein (CRP) (MD -0.71, 95% CI -0.84, -0.59; p

BACKGROUND: This review aims to systematically evaluate the currently available evidence investigating the use of artificial intelligence (AI) and machine learning (ML) in the field of cardiac transplantation. Furthermore, based on the challenges identified we aim to provide a series of recommendations and a knowledge base for future research in the field of ML and heart transplantation. METHODS: A systematic database search was conducted of original articles that explored the use of ML and/or AI in heart transplantation in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to November 2021. RESULTS: Our search yielded 237 articles, of which 13 studies were included in this review, featuring 463 850 patients. Three main areas of application were identified: (1) ML for predictive modeling of heart transplantation mortality outcomes; (2) ML in graft failure outcomes; (3) ML to aid imaging in heart transplantation. The results of the included studies suggest that AI and ML are more accurate in predicting graft failure and mortality than traditional scoring systems and conventional regression analysis. Major predictors of graft failure and mortality identified in ML models were: length of hospital stay, immunosuppressive regimen, recipient's age, congenital heart disease, and organ ischemia time. Other potential benefits include analyzing initial lab investigations and imaging, assisting a patient with medication adherence, and creating positive behavioral changes to minimize further cardiovascular risk. CONCLUSION: ML demonstrated promising applications for improving heart transplantation outcomes and patient-centered care, nevertheless, there remain important limitations relating to implementing AI into everyday surgical practices.

Despite the benefits of rapid deployment aortic valve prostheses (RDAVR), conventional sutured valves (cAVR) are more commonly used in the treatment for aortic stenosis. Given the paucity of randomized studies, this study aimed to synthesize available data to compare both treatment options.A systematic search of Pubmed, OVID, and MEDLINE was conducted to retrieve comparative studies for RDAVR versus cAVR in the treatment of aortic stenosis. Out of 1773 returned titles, 35 papers were used in the final analysis, including 1 randomized study, 1 registry study, 6 propensity-matched studies, and 28 observational studies, incorporating a total of 10,381 participants (RDAVR n = 3686; cAVR n = 6310).Random-effects meta-analysis found no difference between the two treatment groups in terms of operative mortality, stroke, or bleeding (p .05). The RDAVR group had reduced cardiopulmonary bypass (standardized mean difference [SMD]: -1.28, 95% confidence interval [CI]: [-1.35, -1.20], p .001) and cross-clamp times (SMD: -1.05, 95% CI: [-1.12, -0.98], p .001). Length of stay in the intensive care unit was also shorter in the RDAVR group (SMD: -0.385, 95% CI: [-0.679, -0.092], p = .010). The risk of pacemaker insertion was higher for RDAVR (odds ratio [OR]: 2.41, 95% CI: [1.92, 3.01], p .001) as was the risk of paravalvular leak (PVL) at midterm follow-up (OR: 2.52, 95% CI: [1.32, 4.79], p = .005). Effective orifice area and transvalvular gradient were more favorable in RDAVR patients (p .05).Despite the benefits of RDAVR in terms of reduced operative time and enhanced recovery, the risk of pacemaker insertion and midterm PVL remains a significant cause for concern.

Objectives: We sought to assess the safety of training in cardiothoracic surgery comparing outcomes of cases performed by trainees versus fully trained surgeons. Methods: EmBase, Scopus, PubMed, and OVID MEDLINE were searched in August 2021 independently by two authors. A third author arbitrated decisions to resolve disagreements. Inclusion criteria were articles on cardiothoracic surgery reporting on outcomes for trainees. Studies were assessed for appropriateness as per CBEM criteria. 892 results were obtained, 27 represented best evidence (2-Meta-analyses, 1-RCT and 24 retrospective cohort studies). Results: 474,160 operative outcomes were assessed for 434,535 CABG (431,329 on-pump vs 3206 off-pump), 3090 AVR, 1740 MVR/repair, 26,433 mixed, 3565 congenital and 4797 thoracic procedures. 398,058 cases were performed by trainees and 75,943 by consultants. 159 cases were indeterminate. There were no statistically significant differences in the patients’ pre-operative risk scores. All studies excluded extreme high-risk patients in emergency setting, patients with poor left ventricular function and re-operation cases that were undertaken by consultants. There were no differences in CPB and clamp times for CABG. Times for valve replacement and repair cases were longer for trainees. There were no differences in the post-operative outcomes including peri-operative myocardial infarction, resternotomy for bleeding, stroke, renal failure, ITU length of stay and total length of stay. One study reported no differences on angiographic graft patency at 1 year. There were no differences in in-hospital or mid-term mortality out to five-years. Discussion: Trainees can perform cardiothoracic surgery in dedicated high-volume units with outcomes comparable to those of fully trained surgeons.

Numerical simulations of blood flow are a valuable tool to investigate the pathophysiology of ascending thoracic aortic aneurysms (ATAA). To accurately reproduce hemodynamics, computational fluid dynamics (CFD) models must employ realistic inflow boundary conditions (BCs). However, the limited availability of in vivo velocity measurements still makes researchers resort to idealized BCs. In this study we generated and thoroughly characterized a large dataset of synthetic 4D aortic velocity profiles suitable to be used as BCs for CFD simulations. 4D flow MRI scans of 30 subjects with ATAA were processed to extract cross-sectional planes along the ascending aorta, ensuring spatial alignment among all planes and interpolating all velocity fields to a reference configuration. Velocity profiles of the clinical cohort were extensively characterized by computing flow morphology descriptors of both spatial and temporal features. By exploiting principal component analysis (PCA), a statistical shape model (SSM) of 4D aortic velocity profiles was built and a dataset of 437 synthetic cases with realistic properties was generated. Comparison between clinical and synthetic datasets showed that the synthetic data presented similar characteristics as the clinical population in terms of key morphological parameters. The average velocity profile qualitatively resembled a parabolic-shaped profile, but was quantitatively characterized by more complex flow patterns which an idealized profile would not replicate. Statistically significant correlations were found between PCA principal modes of variation and flow descriptors. We built a data-driven generative model of 4D aortic velocity profiles, suitable to be used in computational studies of blood flow. The proposed software system also allows to map any of the generated velocity profiles to the inlet plane of any virtual subject given its coordinate set., Comment: 21 pages, 5 figures, 2 tables To be submitted to "Computer methods and programs in biomedicine" Scripts: https://github.com/saitta-s/flow4D Synthetic velocity profiles: //doi.org/10.5281/zenodo.7251987

The wide uptake of anterior right thoracotomy (ART) as an approach for aortic valve replacement (AVR) has been limited despite initial reports of its use in 1993. Compared with median sternotomy, and even ministernotomy, ART is considered to be less traumatic to the chest wall and to help facilitate quicker patient recovery. In this statement, a consensus agreement is outlined that describes the potential benefits of the ART AVR. The technical considerations that require specific attention are described and the initiation of an ART programme at a UK centre is recommended through simulation and/or use of specialist instruments in conventional cases. The use of soft tissue retractors, peripheral cannulation, modified aortic clamping and the use of intraoperative adjuncts, such as sutureless valves and/or automated knot fasteners, are important to consider in order to circumvent the challenges of minimal the altered exposure via an ART.A coordinated team-based approach that encourages ownership of the programme by team members is critical. A designated proctor/mentor is also recommended. The organisation of structured training and simulation, as well as planning the initial cases are important steps to consider.

Background: Surgical repair of the mitral valve has long been the established therapy for degenerative mitral regurgitation (MR). Newer transcatheter methods over the last decade, such as the MitraClip, serve to restore mitral function with reduced procedural burden and enhanced recovery. This study aims to compare the shortterm and midterm outcomes of MitraClip insertion with surgical repair for MR. Methods: A systematic review of the literature was conducted for studies comparing outcomes between surgical repair and MitraClip. The initial search returned 1850 titles, from which 12 studies satisfied the inclusion criteria (one randomized controlled trial and 11 retrospective studies). Results: The final analysis comprised 4219 patients (MitraClip 1210; surgery 3009). Operative mortality was not different between the groups (odds ratio [OR] = 1.63, 95% confidence interval [CI]: [0.63−4.23]; p = .317). Length of hospital stay was significantly shorter in the MitraClip group (standardized mean difference [SMD] = 0.882, 95% CI: [0.77–0.99]; p 90%; p

A serious complication of transcatheter valves is the mechanistic failure of the deployment system and prosthesis migration. We report the case of a transcatheter aortic valve implantation which failed during implantation resulting in dislodgement of the prosthesis. Emergency surgery to retrieve the deployment system and surgically replace the native valve was the only option to salvage the patient.

BACKGROUND: While minimally invasive techniques for aortic valve replacement (AVR) have been shown to be safe, limited data exist comparing the varying approaches. This study aimed to compare the outcomes between two minimally invasive approaches for AVR: mini-sternotomy (MS) and right anterior thoracotomy (RAT). MATERIALS AND METHODS: A systematic search of MEDLINE, EMBASE, and OVID was conducted for the period 1990-2019. Nine observational studies (n = 2926 patients) met the inclusion criteria. RESULTS: There was no difference in operative mortality between MS and RAT (odds ratio [OR]: 0.87, 95% confidence interval [CI]: 0.41-1.85; P = .709). Meta-analyses favored MS over RAT in reoperation for bleeding (OR: 0.42, 95% CI: 0.28-0.63; P

BACKGROUND: Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.METHODS: PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.RESULTS: Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P CONCLUSIONS: MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.

Background: Thoracic endovascular aortic repair (TEVAR) in selected proximal (Stanford type A) aortic dissection (TAAD) cases has been reported, however, the limitation and criteria for TEVAR applied in TAAD remain controversial. Virtual stent-graft (SG) deployment simulation based on the finite element method is an emerging tool that allows TEVAR to be reproduced for detailed analysis of biomechanical interaction between native vessel wall and SG device. Methods: A TAAD patient underwent an unsuccessful TEVAR followed by salvage open surgical repair. Pre-TEVAR CT angiogram was used to establish the 3D geometry of the dissected aorta for later analysis. Perioperative DSA was used to measure the aortic root motion and determine SG position in the simulation model. Specimen of the harvested aortic tissue was used for histological analysis and tensile test to define isotropic hyperelastic properties of the aortic wall. Results: Aortic root motion was decomposed into a component normal to the sinotubular junction (STJ) and a component parallel to the STJ. The largest motion was 4.14 mm in normal direction and 3.5 mm in parallel direction. The continuous motion was used to define the displacement boundary condition at the aortic root in a finite element model. The histology revealed preserved both elastic fibres and collagen at the proximal landing zone. A small area of inflammatory infiltration was noted at the tunica externa which may related to the dissected lamella. Tensile testing showed that the aortic wall ruptured at the stress of 250-1250 kPa while the lamella ruptured at 80-160 kPa. Simulation precisely reproduced the SG configuration after TEVAR procedure. Maximum principal stress at 301 kPa was found on the lamella during simulation, which is significantly higher than stress tolerance of the lamella. Conclusion: Microstructure of the lamella and aortic wall components determine the capacity in resisting SG induced focal stress. During the deployment, the proximal end of SG landed directly onto the lamella where the maximum stress exceeded the tolerance of the lamella thus causing rupture and allowing the SG to penetrate into the false lumen.

OBJECTIVES This study aims to characterize the material properties of ascending thoracic aortic aneurysmal tissue, using regional biomechanical assessment of both tensile and dissection propagation peel strength. METHODS Thirty-four aneurysm specimens (proximal thoracic aorta) were harvested en-bloc from patients undergoing surgery for aneurysm replacement. Specimens were processed into regional samples of similar shapes covering the whole aneurysm isosurface, according to a structured protocol, in both orientations (longitudinal and circumferential). Thickness mapping, uniaxial tensile and peel tests were conducted, enabling calculation of the following parameters: true stress/strain, tangential modulus, tensile strength, peeling force and dissection energy. Two constitutive material models were used (hyperelastic models of Delfino and Ogden) to fit the data. A circumferential strip of tissue was also obtained for computational histology [regional quantification of (i) elastin, (ii) collagen and (iii) smooth muscle cells]. RESULTS The aortic wall was thinner on the outer curve (2.21, standard deviation (SD) 0.4 mm vs inner curve 2.50, SD 0.12 mm). Advanced patient age and higher pulse wave velocity (externally measured) were predictors of increased aortic wall thickness. Tensile strength was higher in the circumferential versus longitudinal direction when analysed according to anatomical regions. Both peel force (35.5, 22 N/m) and dissection energy (88.5, 69 J/m2) were on average lowest at the outer curve of the aneurysm in the longitudinal orientation. Delfino and Ogden model constants varied throughout anatomical regions, with the outer curve being associated a higher ɑ constant (Delfino) and lower µ1 constant (Ogden) (P 0.05). CONCLUSIONS Our results suggest that the outer aortic curve is more prone to dissection propagation and perhaps less prone to rupture than the inner aortic curve. This strengthens the notion of disease heterogeneity in ascending thoracic aortic aneurysms and has implications for the pathogenesis of aortic dissection.

Our aim was to compare the safety and efficacy of proximal repair (PR) versus extensive repair (ER) for acute type A aortic dissection (ATAAD).A literature search in three databases was performed according to the PRISMA statement. Studies comparing PR versus ER for ATAAD were included. Random-effects meta-analyses were performed.A total of 27 studies incorporating 7113 patients (PR: 5080; ER: 2033) were included. Patients undergoing PR presented decreased in-hospital mortality (odds ratio [OR]: 0.67 [95% Confidence Interval (95% CI) 0.53-0.85]; p 0.01) and post-operative bleeding (OR 0.75 [95% CI 0.60-0.95]; p = 0.02) compared to ER. Meta-regression analysis revealed that in-hospital mortality was not influenced by differences regarding the extent of dissection (p = 0.43). Cardiopulmonary bypass time (SMD:-0.93 [95% CI - 1.22, - 0.66]; p 0.01) and length of hospital stay (SMD:-0.19 [95% CI - 0.34, - 0.05]; p = 0.01) were also lower in the PR group, while there was no difference in terms of renal failure and permanent neurological deficit. The ER approach demonstrated a lower post-discharge mortality compared to PR (OR 1.46 [95% CI 1.09, 1.97]; p = 0.01), while the post-discharge reoperation rate was comparable between the two groups. 1 and 3-year overall survival (OS) were comparable between PR and ER (OR 1.05, [95% CI 0.77-1.44]; p = 0.76) and (OR 1.27 [95% CI 0.86-1.86]; p = 0.23), respectively. The 5-year OS (OR 1.67 [95% CI 1.16-2.41]; p = 0.01) was in favor of the PR arm.In patients with ATAAD, PR was associated with lower odds of in-hospital mortality but higher odds of late mortality. ER and PR demonstrated similar post-operative complication and reoperation rates.

Background: Ethnicity is not incorporated into standardized pre-operative risk-stratification tools for cardiac surgery. This study compared short-term outcomes following coronary artery bypass graft (CABG) surgery in South Asian and non-Asian patients. Methods: Consecutive patients undergoing isolated CABG surgery via sternotomy between the years 2011 and 2019 were retrospectively analyzed. Initially, 1957 patients were identified (799 South-Asian, 40.8%). The patient groups were then propensity matched according to 10 relevant pre-operative covariates (age, body mass index, pulmonary disease, renal failure, smoking, diabetes, ventricular function, renal failure): 675 non-Asian patients were matched against 675 Asian patients. Results: Operative mortality was 1.77% and similar between the two groups (p = 0.447). Multivariate regression analysis found predictors of operative mortality to be pre-operative serum creatinine, age, left ventricular (LV) impairment, and extent of coronary disease. The effect of creatinine on mortality was selective for South-Asian patients (p = 0.015). LV impairment was a predictor of mortality in non-Asian patients, however this effect did not exist in South-Asian patients. Predictors of short-term complications (composite of death, stroke, reoperation, hemofiltration, and pneumonia) were age and creatinine (coefficient 0.002, 95% CI 0.0004–0.004, p = 0.019) in the overall cohort. Subgroup analysis found age to remain a selective negative predictor of complications in South-Asian patients. Cox regression analysis found creatinine, age, and LVEF to influence 10-year survival, whilst ethnicity was not a predictor. Conclusion: This study highlights the cumulative risk associated with ethnicity and renal disease in predicting short-term outcomes following CABG. This warrants further investigations in larger populations, thus guiding pre-operative risk-stratification.

Background The geometrical characterization of ascending thoracic aortic aneurysms in clinical practice is limited to diameter measurements. Despite growing interest in hemodynamic assessment, its relationship with ascending thoracic aortic aneurysm pathogenesis is poorly understood. This study examines the relationship between geometry of the ventriculo-aortic junction and blood flow patterns in ascending thoracic aortic aneurysm disease. Methods Thirty-three patients with ascending thoracic aortic aneurysms (exclusions: bicuspid aortic valves, connective tissue disease) underwent 4-dimensional flow magnetic resonance imaging. After image segmentation, geometrical parameters were measured, including aortic curvature, tortuosity, length, and diameter. A unique angular measurement made by the trajectory of the left ventricular outflow tract axis and the proximal aorta was also conducted. Velocity profiles were quantitatively and qualitatively analyzed. In addition, 11 patients (33%) underwent wall shear stress mapping of the ascending thoracic aortic aneurysm region using computational fluid dynamics simulation. Results Greater left ventricular outflow tract aortic angles were associated with larger aortic diameters at the levels of the sinus (coefficient = 0.387, P = .014) and ascending aorta (coefficient = 0.284, P = .031). Patients with left ventricular outflow tract aortic angles greater than 60° had marked asymmetric flow acceleration on the outer curvature in the proximal aorta, ascertained from 4-dimensional flow analysis. For patients undergoing computational fluid dynamics assessment, regression analysis found that higher left ventricular outflow tract aortic angles were associated with significantly higher wall shear stress values in the outer curve of the aorta (coefficient 0.07, 95% confidence interval 0.04-0.11, P = .002): Angles greater than 50° yielded time-averaged wall shear stress values greater than 2.5 Pa, exhibiting a linear relationship. Conclusions Our findings strengthen the hypothesis of flow-mediated ascending thoracic aortic aneurysm disease progression and that left ventricular outflow tract aortic angle may be a predictor of disease severity.

In this case, we describe an unusual case of dual pathology: i) hypertrophic obstructive cardiomyopathy (HOCM) and ii) aortic root aneurysm. We demonstrate the advantage of a single trans aortic approach to address all components of the HOCM disease. This is illustrated in a video highlighting the main steps of the procedure.

INTRODUCTION Cor-Knot automated fastener has been used as an adjunct in heart valve surgery to eliminate the need for manual tying during valve implantation. Although reduced operative time and facilitation for minimally invasive surgery are clear benefits, whether their use translates to improved patient outcome remains debatable. This study aims to review the safety and efficacy of automated fasteners in heart valve surgeries. METHOD Specific searches were conducted via online medical databases (Pubmed, Embase, Ovid) between 1950 and June 2019. Longitudinal studies were included that provided operative parameters. RESULTS The initial literature search identified 3773 articles, but only eight met the inclusion criteria and were used for analysis: four studies related to aortic valve replacement (AVR), four related to mitral valve (MV) intervention (total n = 810). The meta-analysis revealed the significantly shorter aortic cross-clamp time in the Cor-knot group compared to manual tying, both in AVR and MV surgeries (P

In aortic root aneurysms, the challenge of a valve-sparing aortic root replacement (VSRR) procedure is to ensure durable aortic valve function without reintervention. Although the Bentall procedure defers the durability of valve function to the prosthesis, short- and long-term complications tend to be higher. The aim of this study was to compare the outcomes of VSRR and Bentall procedures in patients with aortic root aneurysms. A systematic literature review was conducted using PubMed regarding the outcomes of the Bentall procedure compared with those of VSRR from the inception of the 2 procedures until July 2018. Studies with short- and long-term comparative data were included. An initial search yielded 9517 titles. Thirty-four studies were finally included for meta-analysis (all retrospective, non-randomized), comprising 7313 patients (2944 valve-sparing and 4369 Bentall procedures) with no evidence of publication bias. Operative mortality was found to be significantly lower in the VSRR group [odds ratio (OR) 0.51, 95% confidence interval (CI) 0.37–0.70; P 0.05). These findings suggest that VSRR is an appropriate and potentially better treatment option for a root aneurysm when the aortic valve is repairable.

OBJECTIVES The aim of this study was to systematically review the simulators that are currently available for coronary artery bypass graft and valve surgery and, in addition, to review the validation evidence supporting them and to recommend several simulators for training based on the analysis of results. METHODS A systematic literature search of the MEDLINE® (1946 to May 2021) and EMBASE® (1947 to May 2021) databases was performed to identify simulators for coronary artery and valvular procedures in cardiothoracic surgery. A selection of keywords and MeSH terms was used to execute the literature search. After identification of relevant articles, data were extracted and analysed. RESULTS Thirty-seven simulators were found in 31 articles. Simulators were found for coronary artery bypass graft (n = 24) and valve surgery (n = 13). The majority of models were either benchtop (n = 28) or hybrid (n = 8) modalities. Evidence of validity was demonstrated in 15 (40.5%) simulators. Twenty-two (59.5%) simulators had no validation evidence, and 1 (2.7%) simulator had 3 or more elements of validity established. CONCLUSIONS Two simulators were recommended for supplemental training in cardiothoracic surgery. Low-fidelity models can provide a broad foundation for surgical skills’ development whereas high-fidelity simulators can be used for immersive training scenarios and appraisals. These should be utilized in early training, at which point the learning curve of trainees is steepest.

At a time where delivering the best quality of care is the raison d’être of the health service, outliers can pose a serious challenge to both clinicians and policy makers. Methods of outlier detection are highly variable. The collection and assimilation of outcome variables can also be very challenging. Despite this, the publication of surgeon specific data has brought the concept of outliers into the public eye and the consequent punitive action affected upon surgeons can be deleterious to clinician psychology and patient perception. Simultaneously, positive outliers are rarely mentioned and never rewarded. Moving forward, the use of more objective outcomes, including novel biomarkers and patient-centred data, as well as innovative statistical strategies and management cultures, can positively evolve the healthcare paradigm for the future.

Artificial intelligence (AI) broadly concerns analytical algorithms that iteratively learn from big datasets, allowing computers to find concealed insights. These encompass a range of operations comprising several terms, including machine learning(ML), cognitive learning, deep learning, and reinforcement learning-based methods that can be used to incorporate and comprehend complex biomedical and healthcare data in scenarios where traditional statistical approaches cannot be implemented. For cardiovascular imaging in particular, machine learning guarantees to be a transformative tool that can address many unmet needs for patient-specific management, accurate prediction of disease progression, and the tracking of identifiable biomarkers of disease processes. In this chapter, the authors discuss fundamentals of machine learning algorithms for image analysis in the cardiovascular system by evaluating the need for ML in this field and examining the potential obstacles and challenges of implementation in the context of three common imaging modalities used in cardiovascular medicine.

Background: Blood flow patterns can alter material properties of ascending thoracic aortic aneurysms (ATAA) via vascular wall remodeling. This study examines the relationship between wall shear stress (WSS) obtained from image-based computational modelling with tissue-derived mechanical and microstructural properties of the ATAA wall using segmental analysis.Methods: Ten patients undergoing surgery for ATAA were recruited. Exclusions: bicuspid aortopathy, connective tissue disease. All patients had pre-operative 4-dimensional flow magnetic resonance imaging (4D-MRI), allowing for patient-specific computational fluid dynamics (CFD) analysis and anatomically precise WSS mapping of ATAA regions (6–12 segments per patient). ATAA samples were obtained from surgery and subjected to region-specific tensile and peel testing (matched to WSS segments). Computational pathology was used to characterize elastin/collagen abundance and smooth muscle cell (SMC) count.Results: Elevated values of WSS were predictive of: reduced wall thickness [coef −0.0489, 95% CI (−0.0905, −0.00727), p = 0.022] and dissection energy function (longitudinal) [−15,0, 95% CI (−33.00, −2.98), p = 0.048]. High WSS values also predicted higher ultimate tensile strength [coef 0.136, 95% CI (0 0.001, 0.270), p = 0.048]. Additionally, elevated WSS also predicted a reduction in elastin levels [coef −0.276, 95% (CI −0.531, −0.020), p = 0.035] and lower SMC count ([oef −6.19, 95% CI (−11.41, −0.98), p = 0.021]. WSS was found to have no effect on collagen abundance or circumferential mechanical properties.Conclusions: Our study suggests an association between elevated WSS values and aortic wall degradation in ATAA disease. Further studies might help identify threshold values to predict acute aortic events.

OBJECTIVES Mitral and tricuspid ring annuloplasty dehiscence with consequent recurrent valve regurgitation is a rare but challenging procedural failure. The incidence and predisposing risk factors for annuloplasty ring dehiscence include technical and pathological ones. METHODS A systematic database search with pooled analysis was conducted of original articles that only included dehiscence rate of mitral and tricuspid ring in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to November 2020. The outcomes included were dehiscence rate in mitral and tricuspid, type of ring implanted, dehiscence rate by pathology and by ring size and shape. RESULTS Our search yielded 821 relevant studies. Thirty-three studies met the inclusion criteria with a total of 10 340 patients (6543 mitral, 1414 tricuspid) of which 87 (mitral) and 30 (tricuspid) had dehiscence. Overall, dehiscence rate was 1.43%, diagnosed at a median of 4.5 ± 1.0 months postoperatively. A significant difference in mitral dehiscence rate was found by ring type (semi-rigid 1.86%, rigid 2.32%; flexible 0.43%; P CONCLUSIONS Although rigid, semi-rigid and flexible annuloplasty rings provide acceptable valve repair outcomes, mitral annuloplasty ring dehiscence is clinically more common among rigid rings. Understanding the multifactorial nature of ring dehiscence will help in identifying the patients at high risk and improve their clinical outcomes.

Abstract Blood flow in the aorta is often assumed laminar, however aortic valve pathologies may induce transition to turbulence and our understanding of turbulence effects is incomplete. The aim of the study was to provide a detailed analysis of turbulence effects in aortic valve stenosis (AVS). Methods Large-eddy simulation (LES) of flow through a patient-specific aorta with AVS was conducted. Magnetic resonance imaging (MRI) was performed and used for geometric reconstruction and patient-specific boundary conditions. Computed velocity field was compared with 4D flow MRI to check qualitative and quantitative consistency. The effect of turbulence was evaluated in terms of fluctuating kinetic energy, turbulence-related wall shear stress (WSS) and energy loss. Results Our analysis suggested that turbulence was induced by a combination of a high velocity jet impinging on the arterial wall and a dilated ascending aorta which provided sufficient space for turbulence to develop. Turbulent WSS contributed to 40% of the total WSS in the ascending aorta and 38% in the entire aorta. Viscous and turbulent irreversible energy losses accounted for 3.9 and 2.7% of the total stroke work, respectively. Conclusions This study demonstrates the importance of turbulence in assessing aortic haemodynamics in a patient with AVS. Neglecting the turbulent contribution to WSS could potentially result in a significant underestimation of the total WSS. Further work is warranted to extend the analysis to more AVS cases and patients with other aortic valve diseases.

Background Abnormal blood flow patterns can alter the material properties of the thoracic aorta via altered vascular biology and tissue biomechanics. In-vivo haemodynamic assessment of the aorta is yet to penetrate clinical practice due to our limited understanding of its effect on aortic wall properties. The decision for surgical treatment is based on size thresholds, limited to a single measurement of aortic diameter from routine imaging, although many aortic dissections (40–60%) occur below these size thresholds. This multi-centre study aims to assess the clinical utility of biomechanics principles in thoracic aortic aneurysm (TAA) risk rupture prediction using a substantial sample size. Methods Fifty-five patients undergoing surgery for root or ascending TAA were recruited from five cardiac centres. Bicuspid aortic valves and connective tissue disease were excluded from this study.Haemodynamic assessment Pre-operative 4-dimensional flow magnetic resonance imaging (4D-MRI) were conducted. Direct 4D-flow analysis and computational fluid dynamics (CFD) were performed creating detailed wall shear stress (WSS) maps across the whole aneurysms. Aortic wall assessment The aneurysmal aortic sample was obtained from surgery and subjected to region specific uniaxial failure tests in the circumferential and longitudinal directions, as well as delamination testing within the aortic media. Whole aneurysm histological characterisation was also conducted using computational pathology techniques. Blood flow, tissue mechanics and microstructural properties were used to develop a risk prediction model with assessment of elastin, collagen and smooth muscle cell composition, as well as failure strain assessment and dissection energy function. Results Outcomes of mechanical properties were: Young's Elastic Modulus as a measure of aortic stiffness (0.85 MPa ±0.69), as well as maximal tensile strength (0.49 MPa ± 0.36), which demonstrated reduced aortic wall strength in the outer curvature. This correlated with increased wall shear stress (WSS) (up to 10 Pa) and flow velocity (up to 43 l/min). Regions of abnormal flow and tissue mechanics correlated significantly with degraded medial microstructure (elastin abundance: 34 vs 66%; collagen abundance 26 vs 57%, p Conclusions CFD modelling has the potential to provide a risk prediction of acute events in TAA beyond the current size classification, as validated by altered aortic tissue properties. Future longitudinal studies are warranted to validate this methods in moderately enlarging thoracic aortas. Flow, mechanical, histology properties Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): NIHR Imperial College BRC

Introduction The study aim was to review the experience of ankle replacement surgery in a university teaching hospital. Methods A retrospective review of primary ankle replacements performed between 2005 and 2019 was undertaken. Implant survival and reasons for revision surgery were assessed, along with patient reported outcomes and complications. Results There were 157 ankle replacements implanted in 140 patients with a mean follow up 7.5 years (range 1.0–14.5). There were 108 Mobility™, 19 Zenith™ and 30 Infinity™ ankle replacements with an overall revision rate of 9.6% at a mean 4.0 years (range 0.1–11.0). Overall survivorship analysis for 5, 10 and 15 years was respectively 92.4%, 89.3% and 86.6%. Discussion The revision rate was comparable to international registers and aseptic loosening was the commonest reason for revision. This study, in a teaching university hospital with an average of 10 primary ankle replacements each year, highlighted ankle arthroplasty provides good functional outcomes and medium term implant survivorship. This supports the use of ankle arthroplasty within foot and ankle specialist centres achieving appropriate outcomes.

BACKGROUND: Porcine aortic roots (PAR) have been reported in the literature with acceptable short- and long-term outcomes for the treatment of aortic root aneurysms. However, their efficacy in type A aortic dissection (TAAD) is yet to be defined. METHODS: Using data from a locally collated aortic dissection registry, we compared the outcomes in patients undergoing aortic root replacement for TAAD using either of two surgical options: (a) PAR or (b) composite valve grafts (CVG). A retrospective analysis was conducted for all procedures in the period from 2005 to 2018. RESULTS: A total of 252 patients underwent procedures for TAAD in the time period. Sixty-five patients had aortic root replacements (PAR n = 30, CVG n = 35). Between-group comparisons identified a younger CVG group (50.5 vs 64.5, P

Background The safety of training in off-pump coronary artery bypass (OPCAB) surgery and the stage at which trainees should be exposed to this technique remain controversial. This single-center retrospective study aimed to compare outcomes of OPCAB surgery in consultant and trainee cases. Methods Between 2014 and 2018, all isolated OPCAB operations performed under the care of a consultant surgeon (G.A.) were analyzed. Cases where a surgeon below consultant grade performed at least 70% of the distal anastomoses were designated as “trainee cases” with the remaining cases designated as “consultant cases.” The baseline characteristics of patients, perioperative data, and short-term outcomes were prospectively collated and analyzed. Results During the study period, 245 OPCAB cases were identified: 142 (58%) consultant and 103 (42%) trainee cases. The trainee cases were performed exclusively by trainees in the final 2 years of the UK National Cardiothoracic Training Program. Both trainee and consultant groups had low mortality with two perioperative deaths occurring in either group. The rates of serious postoperative complications including stroke (n = 1 vs. 2, p = 0.759), resternotomy for bleeding (n = 3 vs. 7, p = 0.431), and mediastinal infection (n = 2 vs. 3, p = 0.926) were low and not significantly different between the two groups. Patients operated on by trainees had a slightly longer hospital stay than those operated on by the consultant surgeon, although this did not reach statistical significance (9.9 vs. 7.9 days). Conclusions These results demonstrate comparable outcomes in OPCAB surgery between a consultant surgeon and trainees. This study supports the conclusion that training surgeons in OPCAB is appropriate for trainees in the final years of cardiac surgery training.

Introduction: Intravenous tranexamic acid (IV TXA) is a recognised pharmaceutical intervention utilised to minimise blood loss and allogenic blood transfusion. However, the use of IV TXA in hip fracture surgery remains inconclusive. We conducted a meta-analysis to investigate the role of TXA in operative hip fracture management on operative and total blood loss, allogenic blood transfusion requirements and impact on venous thromboembolic (VTE) event incidence. Methods: A systematic computerised literature search of PubMed, Medline, Embase, Ovid, The Cochrane Controlled Trials Register, Trip and Google was conducted. We reviewed the efficacy of IV TXA on perioperative blood loss, total blood loss, pre- and postoperative haemoglobin differences, duration of surgery, allogenic blood transfusion requirements and VTE events. Results: 8 studies were eligible including 6 randomised control trials and 2 cohort studies. Patients receiving IV TXA had reduced mean total blood loss of 442.9 mls (95% CI, 426.5-459.3; p0.29) or significant difference on duration of surgery seen with IV TXA usage (p>0.06). Conclusions: Our review demonstrated the efficacy of IV TXA in minimising perioperative, reducing total blood loss and lowering the necessity for allogenic blood transfusions with no significant increased risk in VTE events.

Acute aortic syndrome and in particular aortic dissection (AAD) persists as a cause of significant morbidity and mortality despite improvements in surgical management. This clinical review aims to explore the risks of misdiagnosis, outcomes associated with misdiagnosis and evaluate current diagnostic methods for reducing its incidence.Due to the nature of the pathology, misdiagnosing the condition and delaying management can dramatically worsen patient outcomes. Several diagnostic challenges exist, including low prevalence, rapidly propagating pathology, non-discrete symptomatology, non-specific signs, analogy with other acute conditions and lack of management infrastructure. A similarity to acute coronary syndromes is a specific concern and risks patient maltreatment. AAD with malperfusion syndromes are both a cause of misdiagnosis and marker of disease complication, requiring specifically tailored management plans from the emergency setting.Despite improvements in diagnostic measures, including imaging modalities and biomarkers, misdiagnosis of AAD remains commonplace and current guidelines are relatively limited in preventing its occurrence. This paper recommends the early use of AAD risk scoring, focused echocardiography and most importantly, fast-tracking patients to cross-sectional imaging where the suspicion of AAD is high. This has the potential to improve the diagnostic process for AAD and limit the risk of misdiagnosis. However, our understanding remains limited by the lack of large patient datasets and an adequately audited processes of emergency department practice.

The death rate from thoracic aortic disease is on the rise and represents a growing global health concern as patients are often asymptomatic before acute events, which have devastating effects on health-related quality of life. Biomechanical factors have been found to play a major role in the development of both acquired and congenital aortic diseases. However, much is still unknown and translational benefits of this knowledge are yet to be seen. Phase-contrast cardiovascular magnetic resonance imaging of thoracic aortic blood flow has emerged as an exceptionally powerful non-invasive tool enabling visualization of complex flow patterns, and calculation of variables such as wall shear stress. This has led to multiple new findings in the areas of phenotype-dependent bicuspid valve flow patterns, thoracic aortic aneurysm formation and aortic prosthesis performance assessment. Phase-contrast cardiovascular magnetic resonance imaging has also been used in conjunction with computational fluid modelling techniques to produce even more sophisticated analyses, by allowing the calculation of haemodynamic variables with exceptional temporal and spatial resolution. Translationally, these technologies may potentially play a major role in the emergence of precision medicine and patient-specific treatments in patients with aortic disease. This clinically focused review will provide a systematic overview of key insights from published studies to date.

Background Type A-aortic dissection (TAAD) is a life-threatening diagnosis made in the emergency department (ED). Many presentations mimic acute coronary syndrome (ACS) and over a third of TAAD patients present with raised cardiac enzymes, many of whom have ACS-like changes on the electrocardiogram. The aim of this study was to assess the current practice in diagnosis and management of TAAD. Methods Between April and October 2018, a structured survey was distributed to ED Consultants across the UK. Questions surrounded: i) simulated clinical scenarios which mimicked ACS in the early stages (where TAAD could simultaneously be the diagnosis); and ii) ED infrastructure for TAAD management. Results Responses were received from 175 ED consultants across 70 hospital Trusts. In the context of chest pain and ST elevation, 97% of ED consultants considered this sufficient to diagnose ACS, and over half (54%) agreed with committing to treatment (including the use of thrombolysis) prior to further investigation. Early committers to ACS treatment were statistically less likely to ever order a CT scan or d-dimer (OR 0.31, 95% CI 0.12–0.83, p = 0.02). In total, 32% of consultants reported they would ever request a CT chest in the context of chest pain and elevated troponin. The lack of an AD algorithm was the strongest predictor of clinicians avoiding the use of more definitive investigations for TAAD (OR 0.31, 95% CI 0.01–0.64, p = 0.05). Conclusions In TAAD patients presenting with chest pain and elevated cardiac enzymes there is a high probability of ACS treatment being commenced and a significant risk of failing to request the necessary imaging to diagnose TAAD.

Assessing patient fitness prior to high-risk operations is becoming increasingly vital in cardiothoracic surgery. Physical activity (PA) and frailty measures are powerful perioperative tools, albeit underused in clinical practice. This study aimed to assess the influence of patient frailty on PA postsurgery and other short-term outcomes.Eighty patients undergoing a variety of cardiac surgical procedures (coronary revascularisation, valve repair/replacement, or combination) were recruited to participate. The Reported Edmonton Frailty Scale was used to measure preoperative frailty. As objective measures of PA, participants wore a wrist accelerometer device for 14 days prior to their operation and early in the postoperative period for 30 days.A global reduction in PA was observed in the early postoperative period. Frailty was a significant predictor of reduced light (coefficient -2.23, 95% CI -4.21 to -0.25, P = .028) and moderate activity (coefficient -1.85, 95% CI -2.99 to -0.70, P = .002) postoperatively. Neither frailty nor preoperative PA were predictors of postoperative composite complications. Both frailty (coefficient 0.134, 95% CI 0.106-0.162, P.001) and PA scores (P.05) were strong predictors of length of hospital stay (coefficient 1.76, 95% CI 0.003-3.524, P = .05). Furthermore, patients who stayed in hospital longer were more likely to suffer early postoperative complications (stroke, renal failure, reoperation, pacemaker) if they were frail (P.0001) compared to non-frail patients (P = .607).This study highlights the predictive ability of objective frailty scoring and PA measurement for outcomes after cardiac surgery. This has important implications for surgical risk stratification and personalized postoperative planning.

Background: The subclavian artery is an alternative access route for transcatheter aortic valve implantation (TAVI), with a potential advantage in patients unsuitable for traditional access routes such as the femoral artery. This study aimed to determine the safety and efficacy of the trans-subclavian (TSc) compared to the trans-femoral (TF) approach. Methods: A systematic review was conducted on two online databases: Embase and Medline. The initial search returned 508 titles. Nine observational studies were included: n = 2938 patients (2382 TF and 556 TSc). Results: Both TSc and TF groups were comparable for: 30-day mortality (Odds ratio, OR 0.75, 95% CI 0.49 – 1.16, p = 0.195); in-hospital stroke (OR 1.05, 95% CI 0.60–1.85, p = 0.859); myocardial infarction (OR 1.97, 95% CI 0.74–5.23, p = 0.176); paravalvular leaks (OR 1.20, 95% CI 0.76–1.90, p = 0.439); rates of postoperative permanent pacemaker implantation (OR 1.49, 95% CI 0.92–2.41, p = 0.105); in-hospital bleeding and meta-analysis demonstrated no significant difference between access points (OR 3.44, 95% CI 0.35–34.22, p = 0.292). Procedural time was found to be longer in the TSc group (SMD 1.02; 95% CI 0.815–1.219, p