Machine-Learning-Based Diagnostics of Cardiac Sarcoidosis Using Multi-Chamber Wall Motion Analyses.

BACKGROUND: Hindered by its unspecific clinical and phenotypical presentation, cardiac sarcoidosis (CS) remains a challenging diagnosis. OBJECTIVE: Utilizing cardiac magnetic resonance imaging (CMR), we acquired multi-chamber volumetrics and strain feature tracking for a support vector machine learning (SVM)-based diagnostic approach to CS. METHOD: Forty-five CMR-negative (CMR(-), 56.5(53.0;63.0)years), eighteen CMR-positive (CMR(+), 64.0(57.8;67.0)years) sarcoidosis patients and forty-four controls (CTRL, 56.5(53.0;63.0)years)) underwent CMR examination. Cardiac parameters were processed using the classifiers of logistic regression, KNN(K-nearest-neighbor), DT (decision tree), RF (random forest), SVM, GBoost, XGBoost, Voting and feature selection. RESULTS: In a three-cluster analysis of CTRL versus vs. CMR(+) vs. CMR(-), RF and Voting classifier yielded the highest prediction rates (81.82%). The two-cluster analysis of CTRL vs. all sarcoidosis (All Sarc.) yielded high prediction rates with the classifiers logistic regression, RF and SVM (96.97%), and low prediction rates for the analysis of CMR(+) vs. CMR(-), which were augmented using feature selection with logistic regression (89.47%). CONCLUSION: Multi-chamber cardiac function and strain-based supervised machine learning provides a non-contrast approach to accurately differentiate between healthy individuals and sarcoidosis patients. Feature selection overcomes the algorithmically challenging discrimination between CMR(+) and CMR(-) patients, yielding high accuracy predictions. The study findings imply higher prevalence of cardiac involvement than previously anticipated, which may impact clinical disease management.

The Impact of Bile Duct Cultures on Surgical Site Infections in Pancreatic Surgery.

INTRODUCTION: In pancreatic surgery pre-operative biliary drainage (PBD) is associated with bacteribilia, which increases the risk for surgical site infections (SSIs). METHODS: This study is a retrospective observational cohort design that compared micro-organisms of intra-operative bile duct cultures with micro-organisms of SSIs after pancreaticoduodenectomy. RESULTS: From January 2004 until December 2010, 887 patients underwent pancreaticoduodenectomy or hepaticojejunostomy for benign and malignant peri-ampullary lesions. Surgical site infections occurred in 10% (87/887). Cultures of SSIs with corresponding intra-operative bile duct cultures were available for 59 patients. Sixty-four percent (38/59) had undergone PBD. Pre-operative biliary drainage was associated with positive intra-operative bile duct cultures in 95% (36/38), versus 48% (10/21; p≤0.001). The correlation of SSIs with intra-operative bile duct cultures was 59% (35/59). There was a significant association between the micro-organisms cultured from SSIs and the corresponding bile duct cultures for Enterococcus spp., Escherichia coli, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus (MRSA), Enterobacteriaceae with extended spectrum ß-lactamase (ESBL), and Candida spp. CONCLUSION: After pancreaticoduodenectomy, SSIs are often caused by the same micro-organisms that are present on intra-operative bile duct cultures, especially after PBD. Therefore, intra-operative bile duct cultures should be performed routinely to adjust the antibiotic prophylaxis according to the local hospital surveillance data.