Galectin-3 for Thromboembolic Formation in Patients With Atrial Fibrillation CHA₂DS₂-VASc Scoring

Overview

Atrial Fibrillation is considered as one of a common cardiac arrhythmia that presented with rapid and irregular rhythm and has an increased incidence.There are different types of atrial fibrillation one of these is paroxysmal atrial fibrillation that defined as lasts longer than 30 seconds and lasting less than 7 days, while atrial fibrillation lasting more than 7 days to less than one year or requiring pharmacological or electrical cardioversion is called persistent atrial fibrillation, referring to the American Heart Association 2006 guidelines.Patients with atrial fibrillation suffer from serious complications like stroke due to thromboembolism, heart failure and death. Risk of stroke is 5-folds in patients with atrial fibrillation in addition to presence or absence of another clinical risk factors.

In 2001, the CHADS₂ score (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke) was developed to predict the risk of stroke in patients with non rheumatic atrial fibrillation.In this score, each patient giving one point for congestive heart failure , hypertension , age equal or more than 75 years, diabetes mellitus and two points for stroke, transient ischemic attack. In 2010, CHADS₂ was expanded to include three additional independent risk factors: vascular disease (coronary artery disease, peripheral artery disease, aortic atherosclerosis), age 65-74 years, and female sex. So new, more inclusive scoring system is the CHA₂DS₂-VASc. Each patient giving one point for congestive heart failure, hypertension, diabetes mellitus, vascular disease, age 65-74 and female gender and two point for history of stroke, transient ischemic attack and age≥75. The CHA₂DS₂-VASc score is better to predict stroke risk in non valvular atrial fibrillation patients with a baseline CHADS₂ score of 0 to 1. The 2014 American Heart Association/ American College of Cardiology/ Heart Rhythm Society guidelines also recommend the CHA₂DS₂-VASc for stroke risk in patients with non valvular atrial fibrillation. The 2016 European Society of Cardiology guidelines recommend using the CHA₂DS₂-VASc score to predict stroke risk in atrial fibrillation patients and to give oral anticoagulants to men with a score of 1 or higher and women with a score of 2 or higher. Stroke is a serious vascular problem, 25-30 percent of the cause is atrial fibrillation inspite of paroxysmal or persistent types. Galectin-3 is known as a soluble beta-galactoside binding lectin that secreted by immune cell and mediates profibrotic pathways. Also it has a role in inflammation, cell proliferation, and tissue repair. So, it is involved in multiple diseases as liver, kidney, inflammatory disease. In cardiac disease, it has a role in pathophysiology of atrial fibrillation, heart failure, myocardial infarction as the level is found high in patients with ST segment elevation myocardial infarction than normal persons and according to the level the outcome of disease is suggested. Also if galectin-3 is greater than the median level, the patients have a higher risk of new or recurrent heart failure. Galectin-3 has been approved by the Food and Drug Administration as a prognostic biomarker in congested heart failure to be used in conjunction with clinical evaluation. Galectin-3 has an ability of binding to von willbrand factor so help in modulation of early thrombus formation, as the glycans on human factor VIII are similar to von willbrand factor.