ABSTRACT
BACKGROUND: Despite its lack of efficacy, aspirin is commonly used for stroke prevention in atrial fibrillation. Since prior studies have suggested a benefit of low-intensity anticoagulation over aspirin in the prevention of vascular events, the aim of this systematic review was to compare the outcomes of patients with non-valvular atrial fibrillation treated with low-intensity anticoagulation with Vitamin K antagonists or aspirin. METHODS: We conducted a systematic review searching Ovid MEDLINE, Embase and the Cochrane Central Register of Controlled Trials, from 1946 to October 14th, 2015. Randomized controlled trials were included if they reported the outcomes of patients with non-valvular atrial fibrillation treated with a low-intensity anticoagulation compared to patients treated with aspirin. The primary outcome was a combination of ischemic stroke or systemic embolism. The random-effects model odds ratio was used as the outcome measure. RESULTS: Our initial search identified 6309relevant articles of which three satisfied our inclusion criteria and were included. Compared to low-intensity anticoagulation, aspirin alone did not reduce the incidence of ischemic stroke or systemic embolism OR 0.94 (95% CI 0.57-1.56), major bleeding OR 1.06 (95% CI 0.42-2.62) or vascular death OR 1.04 (95% CI 0.61-1.75). The use of aspirin was associated with a significant increase in all-cause mortality OR 1.66 (95% CI 1.12-2.48). CONCLUSION: In patients with non-valvular atrial fibrillation, aspirin provides no benefits over low-intensity anticoagulation. Furthermore, the use of aspirin appears to be associated with an increased risk in all-cause mortality. Our study provides more evidence against the use aspirin in patients with non-valvular atrial fibrillation.
Subject(s)
Anticoagulants/therapeutic use , Aspirin/therapeutic use , Atrial Fibrillation/drug therapy , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Atrial Fibrillation/physiopathology , Embolism/embryology , Embolism/etiology , Humans , Outcome Assessment, Health Care , Randomized Controlled Trials as Topic , Stroke/prevention & control , Warfarin/therapeutic useABSTRACT
The purpose of this study was to determine the endocrine and circulatory responses of the ovine fetus, near term, to sustained hypoxemic stress superimposed on chronic hypoxemia. Fetal sheep were chronically embolized (n = 7) for 10 days between 0.84 and 0.91 of gestation via the descending aorta until arterial oxygen content was decreased by approximately 30%. Control animals (n = 8) received saline only. On experimental day 10, both groups were embolized over a 6-h period until fetal arterial pH decreased to approximately 7.00. Regional distribution of lower body blood flows was measured on day 10, before and at the end of acute embolization. On day 10, the chronically embolized group had lower arterial oxygen content (P < 0.05), Po2 (P < 0.01), and placental blood flow (P < 0.05) than controls and higher prostaglandin E2 (PGE2) and norepinephrine plasma concentrations (both P < 0.05). In response to a superimposed sustained hypoxemic stress, there was a twofold greater increase in PGE2 in the chronically embolized group than in the control group (P < 0.05). However, the increase in fetal plasma cortisol in response to superimposed hypoxemic stress was similar in both groups, despite significantly lower adrenocorticotropic hormone and adrenal cortex blood flow responses in the chronically hypoxemic group (both P < 0.05). We conclude that PGE2 response to a sustained superimposed reduction in placental blood flow, leading to metabolic acidosis, is enhanced under conditions of chronic hypoxemia and may play an important role for the maintenance of the fetal cortisol response to an episode of superimposed acute stress.
Subject(s)
Embolism/embryology , Endocrine Glands/embryology , Fetus/physiology , Hypoxia/embryology , Stress, Physiological/embryology , Acute Disease , Adrenocorticotropic Hormone/blood , Animals , Blood Pressure , Chronic Disease , Dinoprostone/analysis , Female , Fetal Blood , Fetus/blood supply , Gases/blood , Heart Rate, Fetal , Placenta/blood supply , Pregnancy , Regional Blood Flow , Sheep/embryology , Umbilical Cord/blood supplySubject(s)
Aneurysm/diagnostic imaging , Embolism/diagnostic imaging , Femoral Artery/abnormalities , Iliac Artery/abnormalities , Popliteal Artery/abnormalities , Adult , Aneurysm/complications , Aneurysm/embryology , Arteries/abnormalities , Buttocks/blood supply , Diagnosis, Differential , Embolism/embryology , Embolism/etiology , Femoral Artery/diagnostic imaging , Humans , Iliac Artery/diagnostic imaging , Male , Popliteal Artery/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
Artificial embolisms were produced in chick embryos by injecting small mouse liver cell particles in an extraembryonal vein. 1-10 h after the injection the embryos were fixed, and serial sections were examined by light microscope. Most of the obstructed vessels were later recanalized. All of the emboli were surrounded by thrombocytes and partly fixed on the vessel wall. The smaller of the injected particles were lying outside the vessels in the neighboring mesenchyme. The significance of thrombocytes for this transport mechanism is discussed.
