Swiss Cheese Heart: A Tale of Multiple Valve Perforations.

Gerbode defect, an anomalous connection between the left ventricle and right atrium, is often congenital but can be acquired or iatrogenically formed. We present an exceedingly rare case of this defect associated with multiple valve perforation in an otherwise healthy patient with bicuspid aortic valve and endocarditis.

Modified median quartile double ranked set sampling for estimation of population mean.

Environmental monitoring and assessment aim to gather data economically, without bias, using efficient and cost-effective sampling methods. One such traditional method is Ranked Set Sampling (RSS), often employed to achieve observational economy. This article introduces an innovative two-stage sampling approach for ranked set sampling (RSS) to get a more precise estimate of the population mean. Modified Median Quartile Double Ranked Set Sampling (MMQDRSS) highlights the ranked base technique's potential as a cost-effective sampling method. To evaluate the performance of the proposed estimator by using real-life data and conducting a simulation study to compare the relative efficiency of the proposed estimator with some existing methods.

Integrating endogeneity in survey sampling using instrumental-variable calibration estimator.

The endogeneity problem arises when the auxiliary variables correlate to the error terms. In such cases, appropriate instrumental variables ensure efficient estimation. Calibration has recognized itself as an important methodological tool at a large scale to estimate the population total in survey sampling. Which does not offer efficient estimation in the presence of endogeneity. When endogeneity is present in the auxiliary variables, the calibration using endogenous auxiliary variables may produce biasedness and increase variance due to inappropriate model assumptions. In this article, we propose instrumental-variable calibrated estimators by using the classical instrumental-variables approach for the case of exact identification that are more efficient than conventional calibration estimators when some auxiliary variables are endogenous. The necessary properties of the proposed estimators are presented. Our study is backed by both the simulation study and a real data example to check the performance of the proposed estimators.

A new modified biased estimator for Zero inflated Poisson regression model.

Zero-inflated Poisson (ZIP) model is widely used for counting data with excessive zeroes. The multicollinearity is the common factor in the explanatory variables of the count data. In this context, typically, maximum likelihood estimation (MLE) generates unsatisfactory results due to inflation of mean square error (MSE). In the solution of this problem usually, ridge parameters are used. In this study, we proposed a new modified zero-inflated Poisson ridge regression model to reduce the problem of multicollinearity. We experimented within the context of a specified simulation strategy and recorded the behavior of proposed estimators. We also apply our proposed estimator to the real-life data set and explore how our proposed estimators perform well in the presence of multicollinearity with the help of ZIP model for count data.

A generalized exponential-type estimator for population mean using auxiliary attributes.

In this paper, we propose a generalized class of exponential type estimators for estimating the finite population mean using two auxiliary attributes under simple random sampling and stratified random sampling. The bias and mean squared error (MSE) of the proposed class of estimators are derived up to first order of approximation. Both empirical study and theoretical comparisons are discussed. Four populations are used to support the theoretical findings. It is observed that the proposed class of estimators perform better as compared to all other considered estimator in simple and stratified random sampling.

Influence Diagnostic Methods in the Poisson Regression Model with the Liu Estimator.

There is a long history of interest in modeling Poisson regression in different fields of study. The focus of this work is on handling the issues that occur after modeling the count data. For the prediction and analysis of count data, it is valuable to study the factors that influence the performance of the model and the decision based on the analysis of that model. In regression analysis, multicollinearity and influential observations separately and jointly affect the model estimation and inferences. In this article, we focused on multicollinearity and influential observations simultaneously. To evaluate the reliability and quality of regression estimates and to overcome the problems in model fitting, we proposed new diagnostic methods based on Sherman-Morrison Woodbury (SMW) theorem to detect the influential observations using approximate deletion formulas for the Poisson regression model with the Liu estimator. A Monte Carlo method is done for the assessment of the proposed diagnostic methods. Real data are also considered for the evaluation of the proposed methods. Results show the superiority of the proposed diagnostic methods in detecting unusual observations in the presence of multicollinearity compared to the traditional maximum likelihood estimation method.

Severity of Coronary Artery Disease in Prediabetic Patients Undergoing Elective Coronary Angiography.

Introduction Our objective was to determine the severity frequency of coronary artery disease (CAD) in prediabetes patients undergoing coronary angiography (CAG) in a catheterization laboratory. Materials and methods This descriptive comparative study was conducted on patients who were planned for elective CAG in the hospital from January 2019 to November 2019. The study includes patients age ≥40 years undergoing elective CAG with or without percutaneous coronary intervention/percutaneous transluminal coronary angioplasty. There were 458 patients (381 men and 77 women) in this study that were categorized into three groups on the basis on their glycated hemoglobin (HbA1c) levels: group I (n = 143) as non-diabetes, group II (n = 110) as prediabetes, and group III (n = 205) as diabetes. The severity of CAD was determined using the Gensini score. Results A total of 458 patients were included. Of these, 44.97% had hypertension; n = 36 (25.17%), n = 48 (43.63%), and n = 122 (59.51%) in group I, group II and group III, respectively (P = .0001). A total of 214 (46.72%) had a smoking history. There was a strong family history of CAD in group II (n = 29, 26.36%) and group III (n = 43, 20.98%). Group II and group III patients had a higher extension of CAD than group I (P = .01). Group II (n = 27, 41.54) and group III (n = 65, 50.39%) had a higher frequency of deployment of two stents compared to group I. Conclusion Coronary artery atherosclerosis disease increases parallel to the HbA1c severity and smoking. The present study emphasizes prediabetes as an independent risk factor for CAD.

Inflammatory myopathy associated with anti-mitochondrial antibodies: A distinct phenotype with cardiac involvement.

OBJECTIVE: In the context of clinical evaluations performed on our prospective myositis cohort, we noted a striking association of severe cardiac disease in myositis patients with anti-mitochondrial antibodies. We sought to review all cases of anti-mitochondrial antibody (AMA) associated myositis in our cohort to describe the clinical features of this disease subset. METHODS: We identified 7 patients with confirmed anti-mitochondrial antibodies who presented as an inflammatory myopathy. A retrospective chart review was completed to assess their clinical presentation, laboratory, imaging, electrophysiologic, and histopathologic features. RESULTS: One patient presented with dermatomyositis and 6 were classified as polymyositis using Bohan and Peter criteria. In all but one patient, a chronic course of muscle involvement was appreciated with an average of 6.5 years of weakness prior to presentation. Muscle atrophy was often noted, as well as atypical findings of scapular winging in 2 of the patients. Muscle biopsies were consistent with immune-mediated necrotizing myopathy in 4 patients, dermatomyositis in 1, polymyositis in 1 and nonspecific or granulomatous myositis in 1 patient. Changes pointing to mitochondrial alterations were seen in 2 of the 7 patients. Cardiac involvement (including myocarditis, atrial and ventricular arrhythmias, and cardiomyopathy), was seen in 5 out of 7 (71%) of the patients, and usually preceded the muscle involvement. Coexisting autoimmune conditions were seen in 3/7of the patients and included primary biliary cirrhosis, autoimmune hepatitis, psoriasis, and Hashimoto's thyroiditis. CONCLUSIONS: Anti-mitochondrial antibodies identify a distinct inflammatory myopathy phenotype that is frequently associated with chronic skeletal muscle disease and severe cardiac involvement. Early recognition of this rare entity as an immune-mediated process is important due to implications for treatment. We propose that anti-mitochondrial antibody status should be determined in patients with a compatible clinical picture.