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Background: Ensemble tree-based models such as Xgboost are highly prognostic in cardiovascular medicine, as measured by the Clinical Effectiveness Metric (CEM). However, their ability to handle correlated data, such as hospital-level effects, is limited. Objectives: The aim of this work is to develop a binary-outcome mixed-effects Xgboost (BME) model that integrates random effects at the hospital level. To ascertain how well the model handles correlated data in cardiovascular outcomes, we aim to assess its performance and compare it to fixed-effects Xgboost and traditional logistic regression models. Methods: A total of 227,087 patients over 17 years of age, undergoing cardiac surgery from 42 UK hospitals between 1 January 2012 and 31 March 2019, were included. The dataset was split into two cohorts: training/validation (n = 157,196; 2012–2016) and holdout (n = 69,891; 2017–2019). The outcome variable was 30-day mortality with hospitals considered as the clustering variable. The logistic regression, mixed-effects logistic regression, Xgboost and binary-outcome mixed-effects Xgboost (BME) were fitted to both standardized and unstandardized datasets across a range of sample sizes and the estimated prediction power metrics were compared to identify the best approach. Results: The exploratory study found high variability in hospital-related mortality across datasets, which supported the adoption of the mixed-effects models. Unstandardized Xgboost BME demonstrated marked improvements in prediction power over the Xgboost model at small sample size ranges, but performance differences decreased as dataset sizes increased. Generalized linear models (glms) and generalized linear mixed-effects models (glmers) followed similar results, with the Xgboost models also excelling at greater sample sizes. Conclusions: These findings suggest that integrating mixed effects into machine learning models can enhance their performance on datasets where the sample size is small. [ABSTRACT FROM AUTHOR]

Background/Objectives: Grafting of LIMA to LAD has long been considered the gold-standard conduit choice for patients undergoing CABG. Despite this, the LSV remains the most used conduit by volume and some patients may not receive even a single arterial conduit. However, the outcomes in this group are not frequently explored. This study, therefore, compares in-hospital outcomes of patients who underwent CABG without any arterial conduits to those who received at least one arterial conduit. Methods: Retrospective propensity-matched database analysis of consecutive patients undergoing CABG in the UK between 1996 and 2019 using data from the National Adult Cardiac Surgery Audit. Results: 335,144 patients underwent CABG, with 6% receiving venous conduits only; matched outcomes are reported for 39,812 patients. In both unmatched and matched groups, we found a significant increase in mortality with the use of veins only (matched mortality 5.3% vs. 3.8%, p < 0.001) with estimated treatment effect for mortality OR 1.43, p < 0.001 (95% CI: 1.31–1.57). We also identified greater rates of post-operative dialysis, IABP insertion, and length of hospital stay in this group. Conclusions: We identified a significant increase in in-hospital mortality with the use of veins only compared to using at least one arterial graft to the LAD. While a single arterial graft should be prioritised wherever possible, venous revascularisation retains a critical role for specific patients. We must, therefore, continue to conduct research addressing the mechanisms underlying and propagating vein graft disease in order better to optimise outcomes for this niche patient group after CABG. [ABSTRACT FROM AUTHOR]

Objective. The learning curve of coronary artery bypass grafting with multiple arterial grafting and without the use of cardiopulmonary bypass (off‐pump) is perceived as an advanced subspeciality associated with increased surgical risk. We compared the trends and early clinical outcomes between trainees and consultants as the first operator in the United Kingdom. Methods. All patients who underwent elective or urgent isolated coronary artery bypass grafting from 1996 to 2019 were extracted from the National Adult Cardiac Surgery Audit database. Trends and early clinical outcomes between trainees and consultants as the first operator were compared in the whole cohort and after propensity score matching. Results. Of the total coronary artery bypass graft procedures, trainees performed 24.39% (n = 79759/327025). Trainees performed 27.10% (63934/235920) on‐pump without multiple arterial graft procedures compared to consultants. The consultants had a shorter cardiopulmonary bypass time (82.81 (SD: 35.36) vs 86.21 (SD: 30.07) minutes, p < 0.001) and aortic cross‐clamp time (48.05 (SD: 22.46) vs 50.66 (SD: 19.49) minutes, p < 0.001). However, consultants had a higher mortality (1.6% vs 1.0%, p < 0.001) and incidence of postoperative dialysis (2.1% vs 1.5%, p < 0.001). Trainees performed 16.78% (8089/48220) multiple arterial graft procedures, with no differences compared with consultants for in‐hospital mortality (1.0% vs 0.9%, p = 0.42), cerebral vascular accident (transient ischaemic attack (0.5% vs 0.5%) and permanent stroke (0.6% vs 0.4%), p = 0.33), return to theatre (4.2% vs 4.47%, p = 0.089), postoperative renal dialysis (1.4% vs 1.1%, p = 0.076), and deep sternal wound infection (0.6% vs 0.6%, p = 0.87). Trainees performed 17.17% (8661/41778) off‐pump cases. Consultants had a higher in‐hospital mortality (1.2% vs 0.9%, p = 0.045) with no differences in cerebral vascular accident (transient ischaemic attack (0.2% vs 0.3%) and permanent stroke (0.4% vs 0.4%), p = 0.27), return to theatre (3.8% vs 3.9%, p = 0.69), postoperative renal dialysis (2.0% vs 1.6%, p = 0.059), and deep sternal wound infection (1.0% vs 0.8%, p = 0.66). Conclusion. Trainees in the United Kingdom have adequate exposure to advanced coronary surgery without compromising patients' safety. [ABSTRACT FROM AUTHOR]

There is limited report of outcomes in women undergoing isolated coronary artery bypass grafting (CABG) with left internal thoracic artery and different second conduits (saphenous vein graft [SVG], radial artery [RA], and right internal thoracic artery [RITA]). The National Adult Cardiac Surgery Audit database was queried for women undergoing isolated CABG with left internal thoracic artery graft in the United Kingdom from 1996 to 2019. Propensity score–based pairwise comparisons were performed between graft types. The primary outcome was in-hospital mortality. The study included 58,063 women (SVG, n = 48,881 [84.2%]; RA, n = 6136 [10.6%]; RITA, n = 2445 [4.2%]). SVG use was stable over the years; RA and RITA use decreased. In-hospital mortality was similar between the RA and RITA grafts (2.3% vs 2.8%; odds ratio [OR], 0.80; 95% CI, 0.53-1.22; P =.39) and between the RA and SVG (2.3% vs 2.0%; OR, 1.20; 95% CI, 0.93-1.55; P =.17) but higher in the RITA group compared with the SVG (2.7% vs 1.4%; OR, 2.04; 95% CI, 1.27-3.36; P =.004). Women receiving the RITA graft were more likely to have sternal wound infection (SWI) compared with the RA (0.6% vs 0.06%; P =.004) and the SVG (0.6% vs 0.2%; P =.032). SWI was consistently associated with higher risk of in-hospital mortality. Conduit selection may affect operative outcomes in women undergoing CABG. The RA shows similar mortality and risk of deep SWI as the SVG. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide OBJECTIVES This nationwide retrospective cohort study assessed the impact of the explanted valve type on reoperative outcomes in aortic valve surgery within the UK over a 23-year period. METHODS Data were sourced from the National Institute for Cardiovascular Outcomes Research (NICOR) database. All patients undergoing first-time isolated reoperative aortic valve replacement between 1996 and 2019 in the UK were included. Concomitant procedures, homograft implantation or aortic root enlargement were excluded. Propensity score matching was utilized to compare outcomes and risk factors for in-hospital mortality was evaluated through multivariable logistic regression. Final model selection was conducted using Akaike Information Criterion through bootstrapping. The primary end point was in-hospital mortality, and secondary end points included postoperative morbidities. RESULTS Out of 2371 patients, 24.9% had mechanical and 75% had bioprosthetic valves implanted during the primary procedure. Propensity matched groups of 324 patients each, were compared. In-hospital mortality for mechanical and bioprosthetic valve explants was 7.1% and 5.9%, respectively (P  = 0.632). On multivariable logistic regression analysis, valve type was not a risk factor for mortality [odds ratio (OR) 0.62, 95% confidence interval (CI) 0.37–1.05; P  = 0.1]. Age (OR 1.03, 95% CI 1.01–1.05; P  < 0.05), left ventricular ejection fraction (OR 1.62, 95% CI 1.08–2.42; P  < 0.05), creatinine ≥ 200 mg/dl (OR 2.21, 95% CI 1.17–4.04; P  < 0.05) and endocarditis (OR 2.66, 95% CI 1.71–4.14; P  < 0.05) emerged as risk factors for mortality. CONCLUSIONS The type of valve initially implanted (mechanical or bioprosthetic) did not determine mortality. Instead, age, left ventricular ejection fraction, renal impairment and endocarditis were significant risk factors for in-hospital mortality. [ABSTRACT FROM AUTHOR]

Perioperative atrial fibrillation (AF) is associated with increased mortality, morbidity, and excess healthcare costs. The objective of our study was to assess if preoperative AF in patients undergoing coronary artery bypass grafting is a predictor of operative mortality, postoperative stroke, and need for postoperative dialysis by interrogating a large registry database. We included all isolated procedures performed between February 1996 and March 2019. We used a generalized linear mixed model to assess the effect of preoperative AF on mortality stroke and the need for postoperative dialysis after adjusting for the relevant confounders derived from EuroSCORE 2. Confounders considered included age, gender, neurological dysfunction, renal dysfunction, recent myocardial infarction, pulmonary disease, unstable angina, NYHA class, pulmonary hypertension, diabetes on insulin and peripheral vascular disease, and urgency of the operation. We treated the hospital and operating consultant as random effect variables. We also performed LV function subgroup analyses to assess the effect of preoperative AF on the outcomes of interest. The incidence of pre-existent AF in the cohort of patients we analyzed (N = 356,040 patients) was 3.5% (N = 12,664). In the unadjusted baseline characteristics, preoperative AF patients had more associated comorbidities. After adjustment, preoperative AF remained a significant predictor of increased mortality (odds ratio [OR]: 1.63, confidence interval [CI] 1.48–1.79, p < 0.001), stroke (OR: 1.33, CI 1.16–1.54, p = 0.001), and need for renal dialysis (OR:1.61, CI 1.46–1.78, p < 0.001). Preoperative AF was a significant predictor of adverse outcomes in patients with moderate and good LV function but not in patients with poor LV function (EF <30%). Our study suggests that preoperative AF is associated with an increased risk for perioperative mortality and stroke in patients undergoing coronary artery bypass grafting. [ABSTRACT FROM AUTHOR]

Background: Currently no national standards exist for the prevention of surgical site infection (SSI) in cardiac surgery. SSI rates range from 1% to 8% between centres.Aim: The aim of this study was to explore and characterize variation in approaches to SSI prevention in the UK and the Republic of Ireland (ROI).Methods: Cardiac surgery centres were surveyed using electronic web-based questionnaires to identify variation in SSI prevention at the level of both institution and consultant teams. Surveys were developed and undertaken through collaboration between the Cardiothoracic Interdisciplinary Research Network (CIRN), Public Health England (PHE) and the National Cardiac Benchmarking Collaborative (NCBC) to encompass routine pre-, intra- and postoperative practice.Findings: Nineteen of 38 centres who were approached provided data and included responses from 139 consultant teams. There was no missing data from those centres that responded. The results demonstrated substantial variation in over 40 aspects of SSI prevention. These included variation in SSI surveillance, reporting of SSI infection rates to external bodies, utilization of SSI risk prediction tools, and the use of interventions such as sternal support devices and gentamicin impregnated sponges.Conclusion: Measured variation in SSI prevention in cardiac centres across the UK and ROI is evidence of clinical uncertainty as to best practice, and has identified areas for quality improvement as well as knowledge gaps to be addressed by future research. [ABSTRACT FROM AUTHOR]

Introduction The National Training Survey (NTS) is conducted annually by the General Medical Council (GMC) to monitor and report on the quality of postgraduate medical education and training. The coronavirus disease 2019 (COVID-19) pandemic had a significant impact on training in cardiothoracic surgery due to the unprecedented restructuring of surgical activity across the UK. We aim to evaluate how the job satisfaction of cardiothoracic surgery trainees was impacted by COVID-19 using the National Training Survey. Methods The National Training Survey in cardiothoracic surgery from 2017 to 2024 was obtained from the General Medical Council website. Job satisfaction for trainees was evaluated using 17 indicators: Adequate Experience, Clinical Supervision, Clinical Supervision Out of Hours, Educational Governance, Educational Supervision, Feedback, Handover, Induction, Local Teaching, Overall Satisfaction, Regional Teaching, Reporting Systems, Rota Design, Study Leave, Supportive Environment, Teamwork and Workload. The pre-pandemic score for each indicator was an average of 2017, 2018 and 2019, while the post-pandemic score was an average of 2022, 2023 and 2024. The overall job satisfaction per year, combining all indicators, was also analysed. Results Thirty-eight cardiothoracic centres were included in this study. There was a reduction in trainees' job satisfaction from pre- to post-pandemic surveys when comparing all 17 indicators together (scored out of 100) (73.87 versus 70.97, p<0.001). There were six out of 17 (35.29%) indicators that demonstrated a significant decrease in job satisfaction amongst trainees: Regional Teaching (70.53 versus 54.53, p<0.001), Adequate Experience (78.65 versus 72.34, p=0.003), Local Teaching (68.26 versus 62.92, p=0.037), Educational Governance (73.78 versus 70.36, p=0.033), Clinical Supervision Out of Hours (91.16 versus 87.95, p=0.005) and Clinical Supervision (91.98 versus 88.92, p=0.014). Conclusion Trainees' job satisfaction significantly decreased after the COVID-19 pandemic. Although the most recent survey suggests job satisfaction amongst trainees may be recovering, further work needs to be done to ensure training standards return to pre-pandemic levels., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, O'Hanlon et al.)

Background: Cardiac surgery triggers a strong inflammatory reaction, which carries significant clinical consequences. Corticosteroids have been suggested as a potential perioperative strategy to reduce inflammation and help prevent postoperative complications. However, the safety and effectiveness of perioperative corticosteroid use in adult cardiac surgery is uncertain. This is an update of the 2011 review with 18 studies added., Objectives: Primary objective: to estimate the effects of prophylactic corticosteroid use in adults undergoing cardiac surgery with cardiopulmonary bypass on the: - co-primary endpoints of mortality, myocardial complications, and pulmonary complications; and - secondary outcomes including atrial fibrillation, infection, organ injury, known complications of steroid therapy, prolonged mechanical ventilation, prolonged postoperative stay, and cost-effectiveness., Secondary Objective: to explore the role of characteristics of the study cohort and specific features of the intervention in determining the treatment effects via a series of prespecified subgroup analyses., Search Methods: We used standard, extensive Cochrane search methods to identify randomised studies assessing the effect of corticosteroids in adult cardiac surgery. The latest searches were performed on 14 October 2022., Selection Criteria: We included randomised controlled trials in adults (over 18 years, either with a diagnosis of coronary artery disease or cardiac valve disease, or who were candidates for cardiac surgery with the use of cardiopulmonary bypass), comparing corticosteroids with no treatments. There were no restrictions with respect to length of the follow-up period. All selected studies qualified for pooling of results for one or more endpoints., Data Collection and Analysis: We used standard Cochrane methods. Our primary outcomes were all-cause mortality, and cardiac and pulmonary complications. Secondary outcomes were infectious complications, gastrointestinal bleeding, occurrence of new post-surgery atrial fibrillation, re-thoracotomy for bleeding, neurological complications, renal failure, inotropic support, postoperative bleeding, mechanical ventilation time, length of stays in the intensive care unit (ICU) and hospital, patient quality of life, and cost-effectiveness. We used GRADE to assess the certainty of evidence for each outcome., Main Results: This updated review includes 72 randomised trials with 17,282 participants (all 72 trials with 16,962 participants were included in data synthesis). Four trials (6%) were considered at low risk of bias in all the domains. The median age of participants included in the studies was 62.9 years. Study populations consisted mainly (89%) of low-risk, first-time coronary artery bypass grafting (CABG) or valve surgery. The use of perioperative corticosteroids may result in little to no difference in all-cause mortality (risk with corticosteroids: 25 to 36 per 1000 versus 33 per 1000 with placebo or no treatment; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.75 to 1.07; 25 studies, 14,940 participants; low-certainty evidence). Corticosteroids may increase the risk of myocardial complications (68 to 86 per 1000) compared with placebo or no treatment (66 per 1000; RR 1.16, 95% CI 1.04 to 1.31; 25 studies, 14,766 participants; low-certainty evidence), and may reduce the risk of pulmonary complications (risk with corticosteroids: 61 to 77 per 1000 versus 78 per 1000 with placebo/no treatment; RR 0.88, 0.78 to 0.99; 18 studies, 13,549 participants; low-certainty evidence). Analyses of secondary endpoints showed that corticosteroids may reduce the incidence of infectious complications (risk with corticosteroids: 94 to 113 per 1000 versus 123 per 1000 with placebo/no treatment; RR 0.84, 95% CI 0.76 to 0.92; 28 studies, 14,771 participants; low-certainty evidence). Corticosteroids may result in little to no difference in incidence of gastrointestinal bleeding (risk with corticosteroids: 9 to 17 per 1000 versus 10 per 1000 with placebo/no treatment; RR 1.21, 95% CI 0.87 to 1.67; 6 studies, 12,533 participants; low-certainty evidence) and renal failure (risk with corticosteroids: 23 to 35 per 1000 versus 34 per 1000 with placebo/no treatment; RR 0.84, 95% CI 0.69 to 1.02; 13 studies, 12,799; low-certainty evidence). Corticosteroids may reduce the length of hospital stay, but the evidence is very uncertain (-0.5 days, 0.97 to 0.04 fewer days of length of hospital stay compared with placebo/no treatment; 25 studies, 1841 participants; very low-certainty evidence). The results from the two largest trials included in the review possibly skew the overall findings from the meta-analysis., Authors' Conclusions: A systematic review of trials evaluating the organ protective effects of corticosteroids in cardiac surgery demonstrated little or no treatment effect on mortality, gastrointestinal bleeding, and renal failure. There were opposing treatment effects on cardiac and pulmonary complications, with evidence that corticosteroids may increase cardiac complications but reduce pulmonary complications; however, the level of certainty for these estimates was low. There were minor benefits from corticosteroid therapy for infectious complications, but the evidence on hospital length of stay was very uncertain. The inconsistent treatment effects across different outcomes and the limited data on high-risk groups reduced the applicability of the findings. Further research should explore the role of these drugs in specific, vulnerable cohorts., (Copyright © 2024 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)