Effect of the arteriovenous access for hemodialysis on subendocardial viability ratio, pulse pressure and hospitalizations.

BACKGROUND: In some patients the potential benefits of the arteriovenous (AV) access over catheter for hemodialysis seem to be outweighed by global cardiovascular status deterioration. METHODS: We prospectively evaluated 44 pre-dialysis chronic kidney disease patients submitted to vascular access creation during a follow-up of 25 ± 9 months. We performed pulse wave analysis and biochemical assessment before and 2 months after AV access construction, and we registered premature vascular access thrombosis, and all-cause and cardiovascular hospitalizations throughout follow-up. RESULTS: We found a statistically significant decrease in the subendocardial viability ratio (SEVR) and pulse pressure (PP) parameters after AV access creation while brain natriuretic peptide significantly increased. Receiver operating characteristic curve analysis identified SEVR ≤113 % evaluated 2 months after vascular access construction as the best cutoff value for predicting all-cause and cardiovascular hospitalizations. Kaplan-Meier analysis showed that a SEVR ≤113 % was associated with all-cause (p = 0.010) and cardiovascular (p = 0.029) hospitalizations; Cox regression analysis verified a 4.9-fold higher risk of all-cause hospitalization in patients with SEVR ≤113 % (p = 0.005). CONCLUSION: To our best knowledge, this report indicates, for the first time, that despite the decrease in PP parameters, the creation of a vascular access for hemodialysis was also associated with a reduction of SEVR which predicted a worse clinical outcome. We argue that the decrease of pulse pressure after arteriovenous construction may reflect a new hemodynamic set-point after vascular access creation and may not indicate a protective cardiovascular effect.

[Inflammatory myopathy with an unusual evolution]. / Miopatia inflamatória com evolução menos comum.

Inflammatory myopathies are a heterogeneous group of conditions characterized by proximal muscle weakness, nonsuppurative inflammation of skeletal muscle, with elevated muscle enzyme levels and characteristic electromyography and muscle biopsy findings. The authors describe a clinical case of a young woman, admitted with a four day history of bilateral thigh myalgia. She was afebrile and without skin, mucosal or joint involvement. Thigh muscle palpation was painful. Complete blood count revealed leukopenia and thrombocytopenia. High levels of creatine kinase, serum aminotransferases and myoglobin were detected. Metabolic, toxic and drug-related causes were excluded as well as infectious diseases, malignant tumours and endocrine myopathies. Auto-antibodies for connective diseases were negative. Magnetic resonance imaging and electromyography of lower limbs were suggestive of inflammatory myopathy. Generalized muscle weakness and dysphagia were reported subsequently. Clinical and laboratorial improvement was seen after corticotherapy. Muscle biopsy revealed myopathy signs without inflammatory changes or vasculitis. After prednisolone reduction, presently without treatment, she remains asymptomatic with normal laboratorial findings. The authors emphasize in this case of inflammatory myopathy the unusual clinical and laboratory evolution and the importance of a cautious differential diagnosis.

Diagnostic testing, pre- and post-test probabilities, and their use in clinical practice.

In the process of establishing a diagnosis, the clinician calculates the disease probabilities, which keep changing as data is gathered from clinical history, physical examination and laboratory and imaging data. This paper sets out to explain, in a simple and practical way, how the characteristics of a test can be applied in order to determine post-test probability, that is, the probability of a specific disease being present. Before applying the test, we start with a pretest probability that corresponds to the prevalence of the disease. With each additional test this probability changes, until a threshold is reached that includes or excludes the clinical diagnosis. To calculate the post-test probabilities, the sensitivity and specificity of the test are used to calculate the positive and negative predictive values for a determined pretest probability, as well as likelihood ratios (through graphics or nomograms, approximations or equations). Among the test characteristics, the most useful for calculating post-test probabilities are likelihood ratios, which have several advantages over sensitivity and specificity.

The therapeutic approach to paroxysmal or persistent atrial fibrillation: rhythm control versus rate control. A review.

Atrial fibrillation (AFib) is the commonest form of arrhythmia in patients with or without cardiac disease. There is still controversy concerning the best treatment for paroxysmal or persistent atrial fibrillation: rhythm control (conversion of AFib to sinus rhythm) or rate control (control of ventricular rate with maintenance of AFib). This review aims to discuss the best evidence available on the initial approach to paroxysmal or persistent AFib. We found four major articles, whose results failed to prove the superiority of one approach over the other. However, there was a non-statistically significant tendency in favor of rate control in a set of clinically important results. Based on this data, we recommend rate control as the first approach to paroxysmal or persistent AFib.

Statin therapy in the primary and secondary prevention of coronary artery disease in patients with type 2 diabetes. A scientific review.

Type 2 diabetes mellitus has a high and growing prevalence in industrialized countries and constitutes a major cardiovascular risk, often being found in association with other risk factors. Macrovascular complications (coronary, cerebrovascular and peripheral) are the main causes of diabetic morbidity and mortality. Dyslipidemia, a major cardiovascular risk factor, is common in patients with type 2 diabetes. Statins are a safe and efficacious therapy in this context. There are a number of good quality randomized controlled trials evaluating the benefit of statins in type 2 diabetic patients. We will present and discuss the most valid, important and applicable evidence available on primary and secondary prevention of coronary artery disease with statins in patients with type 2 diabetes. We will give practical evidence-based recommendations on selection of patients for prevention with statins.