Longitudinal Model Shifts of Machine Learning-Based Clinical Risk Prediction Models: Evaluation Study of Multiple Use Cases Across Different Hospitals.

Background: In recent years, machine learning (ML)-based models have been widely used in clinical domains to predict clinical risk events. However, in production, the performances of such models heavily rely on changes in the system and data. The dynamic nature of the system environment, characterized by continuous changes, has significant implications for prediction models, leading to performance degradation and reduced clinical efficacy.

Implementation of Evidence-Based International Recommendations Reduces Postoperative Delirium Rate in Patients Undergoing Cardiac Surgery or Interventions: A System-Based Quality Improvement Study.

Background: Delirium is a frequent and serious complication of cardiac procedures that can lead to serious long-term health restrictions. As primary prevention is more effective in reducing rate of delirium than the therapy itself, this study aimed to investigate the effect of a multidisciplinary delirium prevention bundle on the postoperative delirium rate in patients undergoing cardiac procedures.

Methods: In this system-based quality improvement study, a four-component delirium prevention bundle was implemented in patients undergoing cardiac procedures at a single high-volume center.

Evaluating gender bias in ML-based clinical risk prediction models: A study on multiple use cases at different hospitals.

Background: An inherent difference exists between male and female bodies, the historical under-representation of females in clinical trials widened this gap in existing healthcare data. The fairness of clinical decision-support tools is at risk when developed based on biased data. This paper aims to quantitatively assess the gender bias in risk prediction models.

Intraoperative Blood Pressure Management and Its Effects on Postoperative Delirium After Cardiac Surgery: A Single-Center Retrospective Cohort Study.

Objectives: There is accumulating evidence that blood pressure management might be associated with end-organ dysfunction after cardiac surgery. This study aimed to investigate the impact of intraoperative hypotension (IOH) on adverse neurologic outcomes and mortality.

Design: A single-center retrospective cohort study.

How Would We Treat Our Own Cystic Fibrosis With Lung Transplantation?

Lung transplantation is the only therapy for patients with end-stage lung disease. In advanced lung diseases such as cystic fibrosis (CF), life expectancy increases, and it is important to recognize extrapulmonary comorbidities. Cardiovascular involvement, including pulmonary hypertension, right-heart failure, and myocardial dysfunction, are manifest in the late stages of CF disease.

The Efficacy and Safety of a Low-Dose Tranexamic Acid Bolus-Only Protocol Compared with the Moderate-Dose Protocol in Valvular Heart Surgery.

In 873 propensity score-matched pairs of patients undergoing valvular heart surgery, we compared a "moderate dose" of tranexamic acid (TXA) protocol (group 1; median TXA dose: 24 mg/kg body weight) with a 1.5-g "bolus-only" protocol (group 2; median TXA dose: 19 mg/kg body weight). The number of transfused patients was higher in group 2 than in group 1 (74.

Tranexamic Acid and the Risk of Delirium after Off-Pump Surgery.

We investigated whether in patients undergoing off-pump coronary artery bypass grafting surgery a single bolus of 1 g tranexamic acid (TXA) impacts the risk of postoperative delirium using the propensity score matching approach. In 2,757 pairs, the risk of delirium was 4.2% (TXA group) and 5.

Machine Learning-Based Prediction Models for Different Clinical Risks in Different Hospitals: Evaluation of Live Performance.

Background: Machine learning algorithms are currently used in a wide array of clinical domains to produce models that can predict clinical risk events. Most models are developed and evaluated with retrospective data, very few are evaluated in a clinical workflow, and even fewer report performances in different hospitals. In this study, we provide detailed evaluations of clinical risk prediction models in live clinical workflows for three different use cases in three different hospitals.

Preoperative Risk Factors and Early Outcomes of Delirium in Valvular Open-Heart Surgery.

Background: Compared with coronary artery bypass grafting surgery, data regarding postoperative delirium are scant in valvular open-heart surgery. Therefore, the goal of this retrospective study was to investigate the incidence, preoperative risk factors, and early outcomes of delirium in a large group of patients undergoing valvular open-heart surgery.

Methods: In 13,229 patients with isolated valvular or combined valvular and bypass surgery, the incidence of postoperative delirium was assessed until discharge.

Risk-adjusted analysis of long-term outcomes after on- versus off-pump coronary artery bypass grafting.

Objectives: Recent data suggested that off-pump coronary artery bypass (OPCAB) may carry a higher risk for mortality in the long term when compared to on-pump coronary artery bypass (ONCAB). We, therefore, compared long-term survival and morbidity in patients undergoing ONCAB versus OPCAB in a large single-centre cohort.

Methods: A total of 8981 patients undergoing isolated elective/urgent coronary artery bypass grafting between January 2009 and December 2019 were analysed.

Artificial intelligence predicts delirium following cardiac surgery: A case study.

Delirium is a highly relevant complication of surgical interventions. Current research indicates that despite increased awareness for delirium, it is often overlooked. We implemented an AI-based tool to monitor delirium in cardiac surgery patients in our specialist clinic.

Effects of controlled ovarian stimulation on vascular barrier and endothelial glycocalyx: a pilot study.

Purpose: Controlled ovarian stimulation significantly amplifies the number of maturing and ovulated follicles as well as ovarian steroid production. The ovarian hyperstimulation syndrome (OHSS) increases capillary permeability and fluid extravasation. Vascular integrity intensely is regulated by an endothelial glycocalyx (EGX) and we have shown that ovulatory cycles are associated with shedding of EGX components.

Impairment of Cognitive Function in Different Domains Early After Lung Transplantation.

In this prospective observational pilot study patients with the diagnosis of end-stage lung disease and listed for lung transplantation underwent a cognitive function test battery before and after lung transplantation to investigate postoperative cognitive function in three domains (visual and verbal memory, executive functioning, concentration/speed of processing). Additionally we investigated intraoperative risk factors for postoperative cognitive dysfunction. In total, 24 patients were included in this pilot study.

A scalable approach for developing clinical risk prediction applications in different hospitals.

Objective: Machine learning (ML) algorithms are now widely used in predicting acute events for clinical applications. While most of such prediction applications are developed to predict the risk of a particular acute event at one hospital, few efforts have been made in extending the developed solutions to other events or to different hospitals. We provide a scalable solution to extend the process of clinical risk prediction model development of multiple diseases and their deployment in different Electronic Health Records (EHR) systems.

Associations of preoperative stroke and tranexamic acid administration with convulsive seizures in valvular open-heart surgery.

In cardiac surgery, use of the antifibrinolytic agent tranexamic acid (TXA) and acute perioperative stroke are both associated with convulsive seizures. We hypothesized that an older (preoperative) stroke increases the risk of TXA-associated seizures as well. To test this hypothesis, we retrospectively analyzed data from 16,110 patients who had undergone open-heart valvular surgery at our institution between 2009 and 2020.

Moderate Dose of Tranexamic Acid and Complications after Valvular Heart Surgery.

Background: In valvular open-heart surgery, data regarding the effect of a moderate dose of tranexamic acid (TXA) on clinical outcomes are limited.

Methods: Out of a cohort of 13,293 patients, we performed a propensity-score-matched analysis in 6,106 patients and assessed the risk of convulsive seizures (CS, primary endpoint), stroke, renal replacement therapy, and mortality (secondary endpoints). In the entire study cohort of 13,293 patients, we also assessed the multivariable-adjusted association of CS with postoperative outcomes.

Perioperative management of patients with undergoing durable mechanical circulatory support.

Durable mechanical circulatory support (MCS) devices revolutionized the treatment options for patients with end-stage heart failure (HF). Implantation of durable mechanical support has become an integral treatment modality in end-stage HF patients and it is associated with improved quality of life and survival. There is no doubt that this needs an interdisciplinary and interprofessional approach of cardiac surgeons, cardiologists, cardiac anesthesiologists, perfusionists, intensivists, psychologists, assist device coordinators as well as physiotherapists and intensive care.

Hypoxic-inflammatory responses under acute hypoxia: In Vitro experiments and prospective observational expedition trial.

Induction of hypoxia-inducible-factor-1α (HIF-1α) pathway and HIF-target genes allow adaptation to hypoxia and are associated with reduced incidence of acute mountain sickness (AMS). Little is known about HIF-pathways in conjunction with inflammation or exercise stimuli under acute hypobaric hypoxia in non-acclimatized individuals. We therefore tested the hypotheses that 1) both hypoxic and inflammatory stimuli induce hypoxic-inflammatory signaling pathways in vitro, 2) similar results are seen in vivo under hypobaric hypoxia, and 3) induction of HIF-dependent genes is associated with AMS in 11 volunteers.

Tranexamic acid and convulsive seizures after isolated coronary artery bypass surgery: the role of cardiopulmonary bypass and renal function.

In cardiac surgical patients, tranexamic acid (TXA) has been associated with an increased risk of convulsive seizure (CS). We aimed to investigate whether in patients undergoing isolated coronary artery bypass grafting (CABG) surgery the use of cardiopulmonary bypass (CPB) impacts the risk of CS. We studied 4198 propensity score matched patients.

Non-invasive evaluation of macro- and microhemodynamic changes during induction of general anesthesia - A prospective observational single-blinded trial.

Background: Hypotension and bradycardia are known side effects of general anesthesia, while little is known about further macro- and microhemodynamic changes during induction. Intriguing is furthermore, why some patients require no vasopressor medication to uphold mean arterial pressure, while others need vasopressor support.

Objective: Determination of macro- and microhemodynamic changes during induction of general anesthesia.