Effect of β-blockers on the risk of atrial fibrillation in patients with acute myocardial infarction

INTRODUCTION: Oral &#946;-blockers improve the prognosis of patients with acute myocardial infarction, while atrial fibrillation worsens the prognosis of this population. The reduction of atrial fibrillation incidence in patients treated with &#946;-blockers could at least in part explain the benefits of this drug. OBJECTIVE: To investigate the effect of &#946;-blockers on the incidence of atrial fibrillation in patients with acute myocardial infarction. METHODS: We analyzed 1401 patients with acute myocardial infarction and evaluated the occurrence or absence of atrial fibrillation, the use of oral &#946;-blockers and mortality during the first 24 hours. RESULTS: a) The use of &#946;-blockers was inversely correlated with the presence of atrial fibrillation (&#961; = 0.004; OR = 0.54). b) Correlations with mortality were as follows: 31.5% in patients with atrial fibrillation, 9.2% in those without atrial fibrillation (&#961; < 0.001; Odds Ratio = 4.52), and 17.5% in patients not treated with &#946;-blockers and 6.7% in those who received the drug (&#961; < 0.001; OR = 0.34). c) Adjusted Models: The presence of atrial fibrillation was independently correlated with mortality (OR = 2.48, &#961; = 0.002). The use of &#946;-blockers was inversely and independently correlated with mortality (OR = 0.53; &#961; = 0.002). The patients who used &#946;-blockers showed a lower risk of atrial fibrillation (OR = 0.59; &#961; = 0.029) in the adjusted model. CONCLUSION: The presence of atrial fibrillation and the absence of oral &#946;-blockers increased in-hospital mortality in patients with acute myocardial infarction. Oral &#946;-blockers reduced the incidence of atrial fibrillation, which might be at least partially responsible for the drug's benefit

Effect of β-Blockers on the Risk of Atrial Fibrillation in Patients with Acute Myocardial Infarction

INTRODUCTION: Oral &#946;-blockers improve the prognosis of patients with acute myocardial infarction, while atrial fibrillation worsens the prognosis of this population. The reduction of atrial fibrillation incidence in patients treated with &#946;-blockers could at least in part explain the benefits of this drug. OBJECTIVE: To investigate the effect of &#946;-blockers on the incidence of atrial fibrillation in patients with acute myocardial infarction. METHODS: We analyzed 1401 patients with acute myocardial infarction and evaluated the occurrence or absence of atrial fibrillation, the use of oral &#946;-blockers and mortality during the first 24 hours. RESULTS: a) The use of &#946;-blockers was inversely correlated with the presence of atrial fibrillation (&#961; = 0.004; OR = 0.54). b) Correlations with mortality were as follows: 31.5% in patients with atrial fibrillation, 9.2% in those without atrial fibrillation (&#961; < 0.001; Odds Ratio = 4.52), and 17.5% in patients not treated with &#946;-blockers and 6.7% in those who received the drug (&#961; < 0.001; OR = 0.34). c) Adjusted Models: The presence of atrial fibrillation was independently correlated with mortality (OR = 2.48, &#961; = 0.002). The use of &#946;-blockers was inversely and independently correlated with mortality (OR = 0.53; &#961; = 0.002). The patients who used &#946;-blockers showed a lower risk of atrial fibrillation (OR = 0.59; &#961; = 0.029) in the adjusted model. CONCLUSION: The presence of atrial fibrillation and the absence of oral &#946;-blockers increased in-hospital mortality in patients with acute myocardial infarction. Oral &#946;-blockers reduced the incidence of atrial fibrillation, which might be at least partially responsible for the drug's benefit

Skeletonized coronary arteries: pathophysiological and clinical aspects of vascular calcification

The role of calcification in coronary artery disease is gaining importance, both in research studies and in clinical application. Calcified plaque has long been considered to be the most important atherosclerotic plaque within the arterial tree and frequently presents a challenge for percutaneous intervention. Current investigations have shown that plaque calcification has a dynamic course that is closely related to the magnitude of vascular inflammation. Numerous inflammatory factors synthesized during the early stages of atherosclerosis induce the expression and activation of osteoblast-like cells localized in the arterial wall that produce calcium. There is no doubt that the role of these factors in calcification associated with coronary artery disease could be a crucial strategic point in prevention and treatment. A number of diagnostic imaging methods have been developed in recent years, but their performance needs to be improved. In this context, we undertook an update on coronary calcification, focusing on physiopathology, clinical implications, and imaging techniques

Do Diabetic Patients with Acute Coronary Syndromes Have a Higher Threshold for Ischemic Pain?

Background: Data from over 4 decades have reported a higher incidence of silent infarction among patients with diabetes mellitus (DM), but recent publications have shown conflicting results regarding the correlation between DM and presence of pain in patients with acute coronary syndromes (ACS). Objective: Our primary objective was to analyze the association between DM and precordial pain at hospital arrival. Secondary analyses evaluated the association between hyperglycemia and precordial pain at presentation, and the subgroup of patients presenting within 6 hours of symptom onset. Methods: We analyzed a prospectively designed registry of 3,544 patients with ACS admitted to a Coronary Care Unit of a tertiary hospital. We developed multivariable models to adjust for potential confounders. Results: Patients with precordial pain were less likely to have DM (30.3%) than those without pain (34.0%; unadjusted p = 0.029), but this difference was not significant after multivariable adjustment, for the global population (p = 0.84), and for subset of patients that presented within 6 hours from symptom onset (p = 0.51). In contrast, precordial pain was more likely among patients with hyperglycemia (41.2% vs 37.0% without hyperglycemia, p = 0.035) in the overall population and also among those who presented within 6 hours (41.6% vs. 32.3%, p = 0.001). Adjusted models showed an independent association between hyperglycemia and pain at presentation, especially among patients who presented within 6 hours (OR = 1.41, p = 0.008). Conclusion: In this non-selected ACS population, there was no correlation between DM and hospital presentation without precordial pain. Moreover, hyperglycemia correlated significantly with pain at presentation, especially in the population that arrived within 6 hours from symptom onset

Suplementação mineral e mobilização de cálcio nos ossos de eqüinos em pastagem de Brachiaria humidicola

During 150 days 12 female Quarter Horse yearlings at one year of age were kept solely on Brachiaria humidicola pasture, on a complete randomized design, with three treatments and four replications: level 0 (NRC1989); level 50 (50% above NRC); level 100 (100% above NRC). It was used 270 g of sugar as an intake promoter. Biopsis were perfomed on the wing of ileum of each animal, one at the onset and the other at the end of trial, in order to evaluate Ca mobilization and Ca:P of the bone. Forage samples were collected monthly to evaluate oxalate levels and chemical composition. There was a time effect on Ca mobilization and Ca:P (P< 0.05), regardless the treatments. The average of the three treatments, at the onset and at the end of the trial, for Ca and P levels and Ca:P was, respectively: 10.05, 5.22, 1.93:1 and 6.24, 4.06, 1.54:1. The levels of oxalate in the grass varied from 1.18 to 2.00%. Suplementing Ca to young horses at a level 200% greater than the National Research Council recomendation did not prevent Ca mobilization from the bone when the animals were grazing Brachiaria humidicola for an extended period of time.Durante 150 dias, 12 potras Quarto-de-Milha de 1 ano de idade permaneceram exclusivamente em pastagem de Brachiaria humidicola, num experimento inteiramente casualizado, com três tratamentos, nível 0 (recomendação do NRC, 1989); nível 50 (50% a mais do NRC); nível 100 (100% a mais do NRC), e quatro repetições. Como palatabilizante foram empregadas 270 g de açúcar. Realizaram-se biópsias na asa do osso do ílio de cada potra, no início e final do experimento, para avaliar a mobilização de Ca e a relação Ca:P. As amostras da gramínea, foram coletadas mensalmente para verificação do teor de oxalato e composição químico-bromatológica. Houve efeito de tempo na mobilização de Ca, P e da relação Ca:P (p < 0,05), independentemente dos tratamentos. As médias dos três tratamentos, no início e final do período experimental foram, quanto aos teores de Ca, P e da relação Ca:P, respectivamente: 10,05, 5,22, 1,93:1 e 6,24, 4,06, 1,54:1. O teor do oxalato na gramínea variou de 1,18 a 2,00%. A utilização do nível de cálcio suplementar duas vezes superior ao recomendado pelo National Research Council não foi suficiente para impedir a mobilização deste mineral nos ossos de eqüinos pastejando Brachiaria humidicola por longos períodos