BackgroundCoronary artery bypass grafting (CABG) is associated with significant morbidity and mortality. Traditional risk scores, such as the Society of Thoracic Surgery (STS) and EuroSCORE II, have limitations in predicting outcomes, particularly in high-risk patients. Machine learning (ML) models may address these issues by detecting nuanced data patterns not captured by conventional methods. This systematic review and meta-analysis compared the efficacy of ML models with traditional risk scores in predicting outcomes after CABG.MethodsA comprehensive literature search of records up to August 14th 2025, was conducted using PubMed, Embase, Web of Science, and the Cochrane Library. Studies included used ML algorithms and traditional risk scores to predict all-cause mortality (in-hospital, 30-day, or longer term as reported by each study) following CABG. Data extraction and quality assessment were independently performed by two reviewers. Meta-analyses were conducted using a linear mixed-effects model, with C-statistics as the primary measure of discrimination.ResultsTwenty-six studies, comprising 565 063 participants, met the inclusion criteria. The pooled C-statistic for ML models was 0.82 (95% CI 0.79-0.85), significantly higher than the 0.73 (95% CI 0.71-0.76) for traditional risk scores (P < 0.0001). The top-performing ML model achieved a C-statistic of 0.98 (CI 0.95-1.00). Calibration was reported inconsistently across studies and was synthesised narratively rather than quantitatively. Where reported, ML calibration was generally adequate but a robust head-to-head comparison with traditional risk scores was not possible. Subgroup analyses revealed consistent superior performance of ML models across various algorithms and covariate sets.ConclusionsIn this meta-analysis of predominantly internally-validated models, ML approaches showed higher pooled discrimination than traditional risk scores for mortality after CABG. However, given the small number of pooled studies, very high between-study heterogeneity (I2 = 98%), the predominance of high risk-of-bias studies, and the scarcity of external validation, these findings should be interpreted as supporting the promise of ML rather than establishing proof of clinical superiority. Confirmatory prospective, externally validated studies are required before ML can be recommended for routine pre-operative risk stratification.

Background:Acute aortic dissection (AAD) is an emergency associated with high mortality. Timely diagnosis is challenging, and delays may affect patient outcomes. We aimed to identify clinical and temporal factors associated with mortality after AAD. Methodology:We performed a retrospective cohort study across four tertiary hospitals of type A and type B AADs diagnosed over a 20-year period. The outcomes of the study were in-hospital mortality, 30-day mortality, and mid-term (6-month) mortality. Univariate linear and bivariate logistic regression analyses were conducted to evaluate the relationship between mortality and demographic and clinical factors. Results:The study included 149 AAD patients. Of these, 103 (69.1 %) were Stanford type A and 46 (30.9 %) Stanford type B. In-hospital mortality was 29.1 % (n = 30) for type A vs 10.9 % (n = 5) for type B. For type A patients, every one-year increase in age increased odds of in-hospital mortality by 4 % (p = 0.0076), and odds of in-hospital mortality were 10.9 times greater with conservative management than surgical (p < 0.0001). Patients with type A dissection had odds of in-hospital mortality 3.0 times greater than type B (p = 0.0005). 30-day mortality rate was 29.1 % (n = 30) for type A dissection vs 10.9 % (n = 5) for type B. 6-month mortality rate was 30.1 % (n = 31) for type A dissection vs 10.9 % (n = 5) for type B. Predictors of 30-day and 6-month mortality were similar to those of in-hospital mortality. Conclusion:Even with tertiary care AAD carries a high burden of mortality. Those with type A dissections, increased age, and non-surgical management are at an increased risk of mortality.

We describe the case of a 36-year-old woman who underwent redo lung transplantation AFTER a heart-lung transplant 3.5 years prior. The retransplantation was performed through sequential left posterolateral thoracotomy followed by right anterior thoracotomy, without sternal division and without the use of extracorporeal membrane oxygenation or cardiopulmonary bypass support. The patient was found to have undergone an extensive pericardiectomy at the time of the initial heart-lung transplant. The patient recovered uneventfully and complete healing of the airway anastomosis was demonstrated. This novel technique avoids some potential pitfalls of redo lung transplantation after heart-lung transplant.

Primary graft dysfunction (PGD) is a major source of morbidity and mortality following lung transplantation, presenting as acute lung injury within 72 hours post-transplantation. Despite advances in surgical techniques and perioperative care, the complex interplay of donor, recipient, and perioperative factors contributes to its development, underscoring the multifactorial nature of PGD. Clinical management of recipients with PGD relies on supportive care strategies, including lung-protective ventilation, inhaled nitric oxide, and extracorporeal membrane oxygenation (ECMO). Severe cases of PGD may result in significant short- and long-term adverse outcomes, including early mortality. Even for patients who recover from PGD, there is also an associated increased risk of chronic lung allograft dysfunction, further compounding its clinical impact. This review provides a brief review of current knowledge regarding PGD, detailing risk factors, diagnostic criteria, and management approaches while identifying critical gaps in understanding its pathophysiology. Ongoing research is essential to develop innovative therapeutic strategies and improve outcomes for lung transplant recipients.

BACKGROUND:Acute coronary syndrome (ACS) remains one of the leading causes of death globally. Accurate and reliable mortality risk prediction of ACS patients is essential for developing targeted treatment strategies and improve prognostication. Traditional models for risk stratification such as the GRACE and TIMI risk scores offer moderate discriminative value, and do not incorporate contemporary predictors of ACS prognosis. Machine learning (ML) models have emerged as an alternate method that may offer improved risk assessment. This review compares ML models with traditional risk scores for predicting all-cause mortality in patients with ACS. METHODS:PubMed, Embase, Web of Science, Cochrane, CINAHL, Scopus, and IEEE XPlore databases were searched through October 30, 2024, as well as Google Scholar and manual screening of reference lists from included studies and the grey literature for studies comparing ML models with traditional statistical methods for event prediction of ACS patients. The primary outcome was comparative discrimination measured by C-statistics with 95% confidence intervals (CIs) in estimating risk of all-cause mortality. RESULTS:Twelve studies were included (250,510 patients). The summary C-statistic of best-performing ML models across all end points was 0.88 (95% CI 0.86-0.91), compared with 0.82 (95% CI 0.80-0.85) for traditional methods. The difference in C-statistic between ML models and traditional methods was 0.06 (P < 0.0007). Five studies undertook external validation. The PROBAST tool demonstrated high risk of bias for all studies. Common sources of bias included reporting bias and selection bias. Best-performing ML models demonstrated superior discrimination of all-cause mortality for ACS patients compared with traditional risk scores. CONCLUSIONS:Despite outperforming well established prognostic tools such as the GRACE and TIMI scores, current clinical applications of ML approaches remain uncertain, particularly in view of the need for greater model validation.

BACKGROUND:Lower airway enrichment with oral commensals has been previously associated with severe primary graft dysfunction (PGD) after lung transplantation (LT). We aimed to determine whether this dysbiotic signature is present across all PGD severity grades and whether it is associated with a distinct host inflammatory endotype. METHODS:Lower airway samples from 96 LT recipients were used to evaluate the lung allograft microbiota via 16S rRNA gene sequencing. Bronchoalveolar lavage (BAL) cytokine concentrations and cell differential percentages were compared across PGD grades. In a subset of samples, we evaluated the lower airway host transcriptome using RNA sequencing methods. RESULTS:Differential analyses demonstrated lower airway enrichment with supraglottic-predominant taxa (SPT) in moderate and severe PGD. Dirichlet multinomial mixtures modeling identified 2 distinct microbial clusters. A greater percentage of subjects with moderate-severe PGD than no PGD were identified within the dysbiotic cluster (C-SPT, 48% and 29%, respectively) though this did not reach statistical significance (p = 0.06). PGD severity associated with increased BAL neutrophil concentration (p = 0.03) and correlated with BAL concentrations of MCP-1/CCL2, IP-10/CXCL10, IL-10, and TNF-α (p < 0.05). Furthermore, signatures of dysbiosis correlated with neutrophils, MCP-1/CCL-2, IL-10, and TNF-α (p < 0.05). C-SPT exhibited differential expression of TNF, SERPINE1, MPO, and MMP1 genes and upregulation of MAPK pathways, host signling associated with neutrophilic inflammation. CONCLUSIONS:Lower airway dysbiosis within the lung allograft is associated with a neutrophilic inflammatory endotype, an immune profile commonly recognized as the hallmark for PGD. These data highlight a putative role of lower airway microbial dysbiosis in the pathogenesis of this syndrome.

Background: The decision to continue aspirin before elective coronary artery bypass graft surgery remains contentious because of competing thrombotic and bleeding risks. We performed a contemporary systematic review and meta-analysis to compare outcomes between patients undergoing coronary artery bypass grafting who stopped and continued aspirin before surgery. Methods: PubMed, MEDLINE, and CENTRAL databases were searched from inception to 4 October 2023 for randomized controlled trials comparing patients undergoing coronary artery bypass grafting who continued preoperative aspirin with those who discontinued before surgery. Studies with cointervention arms and multivariable-adjusted or propensity matched observational studies were excluded. Summary odds ratios were calculated using a random effects model for dichotomous and continuous variables. Subgroup and sensitivity analyses were conducted in order to explore sources of heterogeneity. Results: Fifteen eligible randomized controlled trials were included with a total of 6,188 patients. Patients who continued aspirin demonstrated no significant difference in all-cause mortality (odds ratio, 1.37; confidence interval, 0.81-2.33), perioperative myocardial infarction (odds ratio, 0.81; confidence interval, 0.55-1.18), and postoperative blood loss (mean difference, 66.12 mL; confidence interval,- 1.45 to 133.69). No significant difference was observed between low-dose and greater doses of aspirin. There was minimal heterogeneity amongst included studies (I2 = 0%, P = .97, I2 = 33%, P = .13, and I2= 76, P = .06, respectively). Studies were of low methodologic quality according to Cochrane Risk of Bias for Randomized Trials. Conclusions: This largest to-date systematic review and meta-analysis found no significant difference for risk of all-cause mortality, perioperative myocardial infarction, and postoperative bleeding between patients continuing and stopping aspirin before coronary artery bypass grafting. (c) 2024 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Rationale: Acute cellular rejection (ACR) after lung transplant is a leading risk factor for chronic lung allograft dysfunction. Prior studies have demonstrated dynamic microbial changes occurring within the allograft and gut that influence local adaptive and innate immune responses. However, the lung microbiome's overall impact on ACR risk remains poorly understood. Objectives: To evaluate whether temporal changes in microbial signatures were associated with the development of ACR. Methods: We performed cross-sectional and longitudinal analyses (joint modeling of longitudinal and time-to-event data and trajectory comparisons) of 16S rRNA gene sequencing results derived from lung transplant recipient lower airway samples collected at multiple time points. Measurements and Main Results: Among 103 lung transplant recipients, 25 (24.3%) developed ACR. In comparing samples acquired 1 month after transplant, subjects who never developed ACR demonstrated lower airway enrichment with several oral commensals (e.g., Prevotella and Veillonella spp.) than those with current or future (beyond 1 mo) ACR. However, a subgroup analysis of those who developed ACR beyond 1 month revealed delayed enrichment with oral commensals occurring at the time of ACR diagnosis compared with baseline, when enrichment with more traditionally pathogenic taxa was present. In longitudinal models, dynamic changes in alpha-diversity (characterized by an initial decrease and a subsequent increase) and in the taxonomic trajectories of numerous oral commensals were more commonly observed in subjects with ACR. Conclusions: Dynamic changes in the lower airway microbiota are associated with the development of ACR, supporting its potential role as a useful biomarker or in ACR pathogenesis.

Xenotransplantation promises to alleviate the issue of donor organ shortages and to decrease waiting times for transplantation. Recent advances in genetic engineering have allowed for the creation of pigs with up to 16 genetic modifications. Several combinations of genetic modifications have been associated with extended graft survival and life-supporting function in experimental heart and kidney xenotransplants. Lung xenotransplantation carries specific challenges related to the large surface area of the lung vascular bed, its innate immune system's intrinsic hyperreactivity to perceived 'danger', and its anatomic vulnerability to airway flooding after even localized loss of alveolocapillary barrier function. This article discusses the current status of lung xenotransplantation, and challenges related to immunology, physiology, anatomy, and infection. Tissue engineering as a feasible alternative to develop a viable lung replacement solution is discussed.

BACKGROUND:Recurrent primary spontaneous pneumothorax (PSP) is routinely treated by video-assisted thoracoscopic (VATS) talc pleurodesis (with or without localized resection of macroscopic bullous disease). There is a paucity of published data regarding durability of the procedure and the rate of recurrent pneumothorax after such surgery, and this has significant implications from a prognostic and employment limitation perspective.METHODS:Patients who underwent a VATS talc pleurodesis (with or without localized resection of macroscopic bullous disease) for the treatment of their second or subsequent PSP or a PSP were followed for recurrent ipsilateral pneumothorax and new contralateral PSP. Follow up was by way of telephone interview and medical record verification out to 48 months.RESULTS:New contralateral pneumothorax occurred in 7 patients (11.1%) in the talc pleurodesis plus wedge resection group and 2 (1.8%) in the talc pleurodesis only group. There was one case of recurrent ipsilateral pneumothorax in a patient who had no inflammatory response to talc insufflation.CONCLUSION:Video-assisted thoracoscopic (VATS) talc pleurodesis (and lung resection for macroscopic bullous disease) is a durable treatment for recurrent PSP. Patients with macroscopic disease have a significant risk of subsequent contralateral PSP.

BACKGROUND The effect of prolonged allograft ischemic time on lung transplant outcomes remains controversial, with most studies associating it with increased mortality, but this effect is partly mitigated by center volume. This study sought to evaluate the mechanism of these findings and clarify the impact of ischemic time on short-term outcomes in a national sample.METHODS Data on lung transplants (January 2010-Janary 2017) were extracted from the Scientific Registry of Transplant Recipients database. Ischemic time was dichotomized as prolonged ischemic time (PIT) or no PIT (N-PIT) at 6 hours. High-volume centers were defined as the top quintile. The primary outcome was 30-day, 1-year, and 3-year mortality; secondary outcomes included in-hospital complications and 72-hour oxygenation.RESULTS Among 11,809 records, there were significant differences between PIT and N-PIT recipients by de-mographics, lung allocation score, and donor organ metrics. In a 1:1 propensity score-matched cohort (n = 6422), PIT recipients had reduced survival compared with N-PIT at 3 years (66.5% vs 68.8%, P = .031). On multivariable analysis, this effect persisted among low-volume but not high-volume centers. PIT recipients were more likely to require rein-tubation, prolonged (>5 days) mechanical ventilation, hemodialysis, longer stay, and acute rejection (all P < .01). Except for reintubation, these disparities were present at both high-and low-volume centers independently. Ischemic time had no effect on 72-hour oxygenation.CONCLUSIONS PIT remains associated with higher rates of postoperative complications and reduced short-term survival. While center volume ameliorated the survival impact, this was not achieved by reducing postoperative com-plications. Further research is warranted before broadening ischemic time thresholds among low-volume centers.(Ann Thorac Surg 2023;116:374-82)& COPY; 2023 by The Society of Thoracic Surgeons. Published by Elsevier Inc.

BACKGROUND:Sensorineural hearing loss (SNHL) may occur following cardiac surgery. Although preventing post-operative complications is vitally important in cardiac surgery, there are few guidelines regarding this issue. This review aimed to characterize SNHL after cardiac surgery. METHOD:This systematic review was registered on PROSPERO and conducted in accordance with PRISMA guidelines. A systematic search of the PubMed, Embase and Cochrane Library were conducted from inception. Eligibility determination, data extraction and methodological quality analysis were conducted in duplicate. RESULTS:There were 23 studies included in the review. In the adult population, there were six cohort studies, which included 36 cases of hearing loss in a total of 7135 patients (5.05 cases per 1000 operations). In seven cohort studies including paediatric patients, there were 88 cases of hearing loss in a total of 1342 operations. The majority of cases of hearing loss were mild in the adult population (56.6%). In the paediatric population 59.2% of hearing loss cases had moderate or worse hearing loss. The hearing loss most often affected the higher frequencies, over 6000 Hz. There have been studies indicating an association between hearing loss and extracorporeal circulation, but cases have also occurred without this intervention. CONCLUSION:SNHL is a rare but potentially serious complication after cardiac surgery. This hearing loss affects both paediatric and adult populations and may have significant long-term impacts. Further research is required, particularly with respect to the consideration of screening for SNHL in children after cardiac surgery.

BACKGROUND:Endoscopic retrograde cholangiopancreatography (ERCP) is a commonly performed procedure worldwide. The aim of this study was to examine cases of mortality after ERCP to identify clinical incidents that are potentially preventable, to improve patient safety.METHODS:The Australian and New Zealand Audit of Surgical Mortality provides an independent and externally peer-reviewed audit of surgical mortality pertaining to potentially avoidable issues. A retrospective review of prospectively collected data within this database was performed for the 8-year audit period from 1 January 2009 to 31 December 2016. Clinical incidents were identified by assessors through first- or second-line review, and thematically coded into periprocedural stages. These themes were then qualitatively analysed.RESULTS:There were 58 potentially avoidable deaths following ERCP, with 85 clinical incidents. Preprocedural incidents were most common (n = 37), followed by postprocedural (n = 32) and then intraprocedural (n = 8). Communication issues occurred across the periprocedural period (n = 8). Preprocedural incidents included delay to procedure, inadequate resuscitative management, decision to perform procedure and inadequate assessment. Intraprocedural incidents comprised technical factors and inadequate support. Postprocedural incidents involved inappropriate treatment, delay in definitive surgical treatment or in recognizing complications, inappropriate second-line intervention and inadequate assessment. Communication incidents comprised inadequate documentation, failure to escalate care and poor inter-clinician communication.CONCLUSION:Causes of mortality following ERCP are wide-ranging, and reviewing clinical incidents associated with potentially avoidable mortality can serve to inform and educate practitioners. In collating a subset of cases in which procedure-related mortality was deemed avoidable, a series of cautionary tales about ERCP is presented that may provide cues to practitioners on improving patient safety and inform future surgical practice.

BACKGROUND: The impact of sex on long-term outcomes after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (PH) remains unclear. We therefore examined the early and long-term outcome after PEA to determine whether sex had an impact on the risk of residual PH and need for targeted PH medical therapy. METHODS: Retrospective study of 401 consecutive patients undergoing PEA at our institution between August 2005 and March 2020 was performed. Primary outcome was the need for targeted PH medical therapy postoperatively. Secondary outcomes included survival and measures of hemodynamic improvement.RESULTS: Females (N = 203, 51%) were more likely to have preoperative home oxygen therapy (29.6% vs 11.6%, p < 0.01), and to present with segmental and subsegmental disease compared to males (49.2% vs 21.2%, p < 0.01). Despite similar preoperative values, females had higher post-operative pulmonary vascular resistance (final total pulmonary vascular resistance after PEA, 437 Dynes center dot s center dot cm(-5 )vs 324 Dynes center dot s center dot cm(-5) in males, p < 0.01). Although survival at 10 years was not significantly different between sexes (73% in females vs 84% in males, p = 0.08), freedom from targeted PH medical therapy was lower in females (72.9% vs 89.9% in males at 5 years, p < 0.001). Female sex remained an independent factor affecting the need for targeted PH medical therapy after PEA in multivariate analysis (HR 2.03, 95%CI 1.03-3.98, p = 0.04).CONCLUSIONS: Although outcomes are excellent for both sexes, females had greater need for targeted PH medical therapy in the long-term. Early reassessment and long-term follow-up of these patients are important. Further investigations into possible mechanisms to explain the differences are warranted. J Heart Lung Transplant 2023;42:1578-1586 (c) 2023 International Society for Heart and Lung Transplantation. All rights reserved.

Lung transplantation is the only potentially curative treatment for end-stage lung failure and successfully improves both long-term survival and quality of life. However, lung transplantation is limited by the shortage of suitable donor lungs. This discrepancy in organ supply and demand has prompted researchers to seek alternative therapies for end-stage lung failure. Tissue engineering (bioengineering) organs has become an attractive and promising avenue of research, allowing for the customized production of organs on demand, with potentially perfect biocompatibility. While breakthroughs in tissue engineering have shown feasibility in practice, they have also uncovered challenges in solid organ applications due to the need not only for structural support, but also vascular membrane integrity and gas exchange. This requires a complex engineered interaction of multiple cell types in precise anatomical locations. In this article, we discuss the process of creating bioengineered lungs and the challenges inherent therein. We summarize the relevant literature for selecting appropriate lung scaffolds, creating decellularization protocols, and using bioreactors. The development of completely artificial lung substitutes will also be reviewed. Lastly, we describe the state of current research, as well as future studies required for bioengineered lungs to become a realistic therapeutic modality for end-stage lung disease. Applications of bioengineering may allow for earlier intervention in end-stage lung disease and have the potential to not only halt organ failure, but also significantly reverse disease progression.

Abstract Background Interhospital transfers of surgical patients are an independent risk factor for mortality. The Australian and New Zealand Audit of Surgical Mortality (ANZASM) aims to improve surgical care through assessment of all cases of surgical mortality. This study aimed to describe common clinical management issues that contributed to interhospital transfer patient mortality. Methods Data for all surgical patient mortality in Australia (except New South Wales) that underwent interhospital transfer between 1 January 2010 and 31 December 2019 were extracted from ANZASM. The surgeons’ reports and assessors’ evaluations were examined to identify clinical management issues. Thematic analysis was performed to develop pertinent themes and subthemes. Results Some 8679 patients were identified over the 10-year period. Of these, 2171 (25.0 per cent) had 3259 clinical management issues identified. Prominent themes were operative design (n = 466, 14.3 per cent), decision to operate (n = 425, 13.0 per cent), medical conditions (n = 344, 10.6 per cent), diagnosis (n = 326, 10 per cent), transfer (n = 293, 10.0 per cent), intraoperative issues (n = 278, 8.5 per cent), inadequate assessment (n = 238, 7.3 per cent), communication (n = 224, 6.9 per cent), delay in recognizing complications (n = 180, 5.5 per cent), coagulopathy (n = 151, 4.6 per cent), insufficient monitoring (n = 127, 3.9 per cent), infection (n = 107, 3.3 per cent), and hospital resources (n = 100, 3.1 per cent). Assessors considered 58.4 per cent of clinical management issues (n = 1903) probably or definitely preventable. Conclusion This study identified 13 themes of potentially avoidable management issues present in surgical mortality following interhospital transfers. Quality-improvement initiatives targeting these areas may improve surgical patient outcomes.