Fast strain mapping in abdominal aortic aneurysm wall reveals heterogeneous patterns.

Abdominal aortic aneurysm patients are regularly monitored to assess aneurysm development and risk of rupture. A preventive surgical procedure is recommended when the maximum aortic antero-posterior diameter, periodically assessed on two-dimensional abdominal ultrasound scans, reaches 5.5 mm. Although the maximum diameter criterion has limited ability to predict aneurysm rupture, no clinically relevant tool that could complement the current guidelines has emerged so far. In vivo cyclic strains in the aneurysm wall are related to the wall response to blood pressure pulse, and therefore, they can be linked to wall mechanical properties, which in turn contribute to determining the risk of rupture. This work aimed to enable biomechanical estimations in the aneurysm wall by providing a fast and semi-automatic method to post-process dynamic clinical ultrasound sequences and by mapping the cross-sectional strains on the B-mode image. Specifically, the Sparse Demons algorithm was employed to track the wall motion throughout multiple cardiac cycles. Then, the cyclic strains were mapped by means of radial basis function interpolation and differentiation. We applied our method to two-dimensional sequences from eight patients. The automatic part of the analysis took under 1.5 min per cardiac cycle. The tracking method was validated against simulated ultrasound sequences, and a maximum root mean square error of 0.22 mm was found. The strain was calculated both with our method and with the established finite-element method, and a very good agreement was found, with mean differences of one order of magnitude smaller than the image spatial resolution. Most patients exhibited a strain pattern that suggests interaction with the spine. To conclude, our method is a promising tool for investigating abdominal aortic aneurysm wall biomechanics as it can provide a fast and accurate measurement of the cyclic wall strains from clinical ultrasound sequences.

Comprehensive assessment of frailty score supplements the existing cardiac surgical risk scores.

OBJECTIVES: The commonly used cardiac surgery risk scores, European System for Cardiac Operative Risk Evaluation II and Society of Thoracic Surgeons score, are inaccurate in predicting mortality in the ageing patient population and do not include the biological age. This requests a need for a new risk score incorporating frailty. The aim of this study was to compare the prediction of mortality and the additive effect of comprehensive assessment of frailty score and the shortened version, frailty predicts death one year after elective cardiac surgery test on the existing risk scores. METHODS: Six hundred four patients undergoing cardiac surgery and aged ≥65 years were included in this prospective observational study. These frailty scores are based on minor physical tests. We compared these frailty score predictions of mortality and their added value to the existing risk scores evaluated by concordance-statistics (C-statistics), integrated discrimination improvement and net reclassification improvement. RESULTS: The median age was 73 years (21% female). C-statistics showed that comprehensive assessment of frailty score with a value of 0.69, frailty predicts death one year after elective cardiac surgery test 0.68, Society of Thoracic Surgeons score 0.70 and European System for Cardiac Operative Risk Evaluation 0.64. Frailty assessment, added to the existing risk scores, significantly improved integrated discrimination improvement up to 0.05, and net reclassification improvement up to 0.04. Frailty assessment also increased the C-statistics, but this did not reach statistical significance. CONCLUSIONS: Frailty scores are as good as the existing risk scores for the prediction of mortality in patients undergoing cardiac surgery. Added to the existing scores, frailty assessment improves the C-statistics and integrated discrimination improvement over time. CLINICAL TRIALS REGISTRATION NUMBER: NCT02992587.

One-year mortality increases four-fold in frail patients undergoing cardiac surgery.

OBJECTIVES: An increased focus on biological age, 'frailty', is important in an ageing population including those undergoing cardiac surgery. None of the existing surgery risk scores European System for Cardiac Operative Risk Evaluation II or Society of Thoracic Surgeons score incorporates frailty. Therefore, there is a need for an additional risk score model including frailty and not simply the chronological age. The aim of this study was to evaluate the impact of frailty assessment on 1-year mortality and morbidity for patients undergoing cardiac surgery. METHODS: A total of 604 patients aged ≥65 years undergoing non-acute cardiac surgery were included in this single-centre prospective observational study. We compared 1-year mortality and morbidity in frail versus non-frail patients. The Comprehensive Assessment of Frailty (CAF) score was used: This is a score of 1-35 determined via minor physical tests. A CAF score ≥11 indicates frailty. RESULTS: The median age was 73 years and 79% were men. Twenty-five percent were deemed frail. Frail patients had four-fold, odds ratios 4.63, 95% confidence interval (CI) 2.21-9.69; P < 0.001 increased 1-year mortality and increased risk of postoperative complications, i.e. surgical wound infections and prolonged hospital length of stay. A univariable Cox proportional hazards regression showed that an increased CAF score was a risk factor of mortality at any time after undergoing cardiac surgery (hazards ratios 1.11, 95% CI 1.07-1.14; P < 0.001). CONCLUSIONS: CAF score identified frail patients undergoing cardiac surgery and was a good predictor of 1-year mortality. CLINICAL TRIAL REGISTRATION NUMBER: NCT02992587.

Coronary artery bypass surgery plus medical therapy versus medical therapy alone for ischaemic heart disease: a protocol for a systematic review with meta-analysis and trial sequential analysis.

BACKGROUND: Despite increasing survival, cardiovascular disease remains the primary cause of death worldwide with an estimated 7.4 million annual deaths. The main symptom of ischaemic heart disease is chest pain (angina pectoris) most often caused by blockage of a coronary artery. The aim of coronary artery bypass surgery is revascularisation achieved by surgically grafting harvested arteries or veins distal to the coronary lesion restoring blood flow to the heart muscle. Older evidence suggested a clear survival benefit of coronary artery bypass graft surgery, but more recent trials yield less clear evidence. We want to assess the benefits and harms of coronary artery bypass surgery combined with different medical therapies versus medical therapy alone in patients with ischaemic heart disease. METHODS: This protocol for a systematic review follows the recommendations of Cochrane and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all randomised clinical trials assessing coronary artery bypass surgery combined with different medical therapies versus medical therapy alone in patients with ischaemic heart disease. We plan to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, Science Citation Index Expanded on Web of Science, and BIOSIS to identify relevant trials. Any eligible trial will be assessed as high risk or low risk of bias, and our conclusions will primarily be based on trials at low risk of bias. The analyses of the extracted data will be performed using Review Manager 5, STATA 16 and trial sequential analysis. For both our primary and secondary outcomes, we will create a 'Summary of Findings' table and use GRADE to assess the certainty of the evidence. DISCUSSION: Coronary artery bypass surgery is invasive and can cause death, which is why its use must be thoroughly studied to determine if it yields a large enough long-term benefit for the thousands of patients receiving it every year. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ID 131924.

Organ Culture as a Model System for Studies on Enterotoxin Interactions with the Intestinal Epithelium.

Studies on bacterial enterotoxin-epithelium interactions require model systems capable of mimicking the events occurring at the molecular and cellular levels during intoxication. In this chapter, we describe organ culture as an often neglected alternative to whole-animal experiments or enterocyte-like cell lines. Like cell culture, organ culture is versatile and suitable for studying rapidly occurring events, such as enterotoxin binding and uptake. In addition, it is advantageous in offering an epithelium with more authentic permeability/barrier properties than any cell line, as well as a subepithelial lamina propria, harboring the immune cells of the gut mucosa.