Left Atrial Inflammation and Platelet Reactivity: A Comparison of Atrial Arrhythmia and an Underlying Substrate

Introduction: Atrial fibrillation (AF) is associated with increased risk of thromboembolic events, which occur as a consequence of left atrial thrombus formation. Rheumatic mitral disease is a potent substrate for AF. Inflammation and platelet hyperactivity are a key process involved in thrombus formation. This study investigated the left atrial specific inflammatory and platelet response in patients with AF and in a chronically remodelled substrate for AF (rheumatic mitral stenosis [MS]) Methods: This study involved 12 patients with AF (CHADS ≤1) undergoing catheter ablation, 19 patients with severe MS (no AF) undergoing balloon mitral valvuloplasty and 6 reference patients with supraventricular tachycardia (SVT) undergoing a electrophysiology study. Blood samples were collected from the left atria (LA) in all patients groups (start of procedure). Plasma levels of vascular cell (VCAM-1) and intracellular (I CAM-1) adhesion molecule were measured as markers of inflammation, with soluble CD40 Ligand (CD40L...