Biomarkers in atrial fibrillation: an overview.

Atrial fibrillation (AF) confers a raised risk of stroke and death, and this risk of adverse events is increased by the coexistence of other cardiovascular risk factors. The pathophysiology of AF is complex, involving the role of inflammation, structural remodelling with apoptosis, inflammation or fibrosis. These changes confer a prothrombotic or hypercoagulable state in this arrhythmia. Despite being easy to use for decision-making concerning oral anticoagulant therapy in AF, clinical risk scores used for stratification have shown modest capability in predicting thromboembolic events, and biomarkers may improve our identification of 'high risk' patients. Biomarkers, whether measured in the peripheral blood, urine or imaging-based may improve our knowledge of the pathophysiology of AF. Importantly these biomarkers could help in the assessment of AF prognosis. The aim of this review was to summarise the published data about biomarkers studied in AF, with focus on data from randomised prospective clinical trials and large community-based cohorts. We will also review the application of these biomarkers to prognosis on the main schemes used to help stratify risk in AF.

Using transportation accident databases to investigate ignition and explosion probabilities of flammable spills.

Risk assessment of hazardous material spill scenarios, and quantitative risk assessment in particular, make use of event trees to account for the possible outcomes of hazardous releases. Using event trees entails the definition of probabilities of occurrence for events such as spill ignition and blast formation. This study comprises an extensive analysis of ignition and explosion probability data proposed in previous work. Subsequently, the results of the survey of two vast US federal spill databases (HMIRS, by the Department of Transportation, and MINMOD, by the US Coast Guard) are reported and commented on. Some tens of thousands of records of hydrocarbon spills were analysed. The general pattern of statistical ignition and explosion probabilities as a function of the amount and the substance spilled is discussed. Equations are proposed based on statistical data that predict the ignition probability of hydrocarbon spills as a function of the amount and the substance spilled. Explosion probabilities are put forth as well. Two sets of probability data are proposed: it is suggested that figures deduced from HMIRS be used in land transportation risk assessment, and MINMOD results with maritime scenarios assessment. Results are discussed and compared with previous technical literature.

A quantitative risk analysis approach to port hydrocarbon logistics.

A method is presented that allows quantitative risk analysis to be performed on marine hydrocarbon terminals sited in ports. A significant gap was identified in the technical literature on QRA for the handling of hazardous materials in harbours published prior to this work. The analysis is extended to tanker navigation through port waters and loading and unloading facilities. The steps of the method are discussed, beginning with data collecting. As to accident scenario identification, an approach is proposed that takes into account minor and massive spills due to loading arm failures and tank rupture. Frequency estimation is thoroughly reviewed and a shortcut approach is proposed for frequency calculation. This allows for the two-fold possibility of a tanker colliding/grounding at/near the berth or while navigating to/from the berth. A number of probability data defining the possibility of a cargo spill after an external impact on a tanker are discussed. As to consequence and vulnerability estimates, a scheme is proposed for the use of ratios between the numbers of fatal victims, injured and evacuated people. Finally, an example application is given, based on a pilot study conducted in the Port of Barcelona, where the method was tested.

Soluble TNFα receptor type I and hepcidin as determinants of development of anemia in the long-term follow-up of heart failure patients.

BACKGROUND: Anemia is common in patients with chronic heart failure (CHF) and is associated with a worse prognosis. This study aims to identify the biological mechanisms which reflect evolutionary changes in the hemoglobin concentrations in heart failure patients who are still not anaemic. METHODS: Fifty-nine patients (54 ± 14 years, 83% males) with CHF (LVEF 28 ± 10%), who did not have anemia, and had not received any previous transfusions, were included. The parameters studied were: iron metabolism (ferritin, iron, transferrin, soluble transferrin receptor (sTfR), hepcidin); inflammation (C-reactive protein, soluble TNFα receptor I (sTNFRI), interleukin 6); and myocardial stress (NT-proBNP, high sensitivity TnT, growth differentiation factor 15). All parameters were measured on inclusion and 1 year after inclusion. RESULTS: Baseline hemoglobin (g/dL) was 14.7 ± 1.5 and at 1 year of follow-up it showed a significant decrease of -0.4 (RIC: -0.7 to -0.06) (p=0.02). At baseline, only the sTNFRI was a predictor of a decrease in hemoglobin 1 year later (p=0.007). During follow-up, the increase in sTNFRI (p=0.002, r=-0.39) and hepcidin (p=0.006, r=-0.35) were both associated with a decrease in hemoglobin. Similarly, the patients who became anemic (13%) had higher levels of hepcidin (p=0.001) and sTNFRI (p=0.008). The remaining parameters did not show any relationship with the evolution in the hemoglobin. CONCLUSIONS: In CHF patients without anemia, the increase in the inflammatory state (sTNFRI) and the following deterioration in the iron metabolism (hepcidin) were the main determinants of a decrease in hemoglobin and the appearance of anemia in the long term follow-up period.