Risk of Chronic Oral Anticoagulation Therapy in Patients Undergoing Primary Percutaneous Coronary Intervention for ST Elevation Myocardial Infarction - Retrospective Cross-Sectional Study

Background: Although chronic oral anticoagulation therapy reduces mortality and morbidity from thromboembolic diseases, the risk of bleeding and mortality may increase when patients on anticoagulation presents with acute ST elevation myocardial infarction (STEMI) where aggressive antiplatelet and further anticoagulation therapies are warranted. Objective: To study the characteristics of patients who are on oral anticoagulation therapy (OAC) at the time of presentation with acute STEMI. Design: Retrospective, cross-sectional study. Setting: All patients who presented to Christiana Care Health System, Newark, DE with acute ST elevation myocardial infarction with intent of primary percutaneous angioplasty between January 2009 and December 2010. Outcome Measures: Composite end-point of major bleeding, in-hospital death, cardiogenic shock, and cardiac arrest. Subgroup analysis of major bleeding and in-hospital mortality. Results: A total of 637 patients were enrolled into the study, the average age of the study population was 61 years, 71% male and 84% Caucasian patients. Of 637 patients, 20 (3.1%) were on OAC at the time of presentation. Both OAC and non-OAC groups differed in baseline characteristics including hypertension, diabetes mellitus, dyslipidemia, peripheral vascular disease, previous coronary artery disease, and pre procedural laboratory data including hemoglobin and INR (all p < 0.05). The groups also differed in the treatment procedures. Patients who were on OAC were more likely to receive bare metal stents and clopidogrel and less likely to be treated with newer antiplatelet agents (prasugrel and ticagrelor) and drug eluting stents (all p <0.05). However, the composite endpoint (death, bleeding, and transfusion) was similar in both groups. On multivariable logistic regression analysis, use of anticoagulation and baseline INR were not significant independent predictors of study endpoints. Pre procedural hemoglobin (OR: 0.88, 95%CI: 0.77-0.98, p=0.012) and requirement of IABP (OR: 4.13, 95% CI: 2.25-7.59, p<0.001) were independent risk factors for study end points. Limitations: Overall sample size for patients who were on anticoagulation was limited due to the low (3%) observed prevalence in the study population, however it is similar to other published studies. The inclusion bias resulting from prehospitalization deaths may influence the results. Conclusions: The contemporary management of acute ST elevation myocardial infarction does not seem to raise the risk of bleeding, in-hospital death, or blood transfusion in patients who are on full anticoagulation

CMB7 receptor modelling of airborne particulate matter in the Vaal Triangle

Bibliography: pages 86-90.The primary aim of the Vaal Air Monitoring (YAM) programme was to do a one year source apportionment study of airborne particulate matter in the Vaal Triangle. The V AM programme was undertaken by Mintek, in South Africa. Three receptor sites were set up, oneea.ch in the Central Business District (CBD) of Vereeniging, Vanderbijlpark and Sasolburg. For this thesis, CMB7 receptor modelling was performed on fifteen samples from the V AM study representing the pre-, mid-, and post-winter periods. Five samples from each receptor site were modelled following the United States Environmental Protection Agency (US-EPA)PM10 protocol. PM10 size selected particulates were collected on 47 mm Teflon and quartz fibre filter substrates over one week sampling periods. Thirty three chemical species were analysed for use in the Chemical Mass Balance receptor model. Teflon filters were used for inorganic elemental analysis. Inorganic elements were determined by energy dispersive X-Ray Fluorescence (EDXRFS), inductively coupled plasma mass spectrometry (ICP-MS) and Atomic Absorption Spectrometry (AAS). The quartz fibre filters were used for the determination of water soluble ions and carbon by Ion Chromatography (IC), and Thermal Optical Reflectance (TOR) respectively. Elemental and ion analyses were done at Mintek. Carbon analyses by TOR were done at the Desert Research Institute (ORI) in Reno Nevada, USA. Generally sample preparation and analysis of filter substrates followed ORI guidelines Where required, in-house methods developed at Mintek were successfully applied

Performance Analysis of Improved Component based Software Reliability Model

Software reliability engineering techniques focus on development and maintenance of software systems. This paper presents a improved component model. The model is used to estimate the reliability of software systems and the usage ration of each component. A component impact analysis which helps in focusing of testing is presented .The proposed method exhibits considerable improvement when compared against conventional methods