Left atrial strain and mechanical dispersion as predictors of atrial fibrillation onset in patients with mild rheumatic mitral stenosis

Abstract

A BSTRACT Chronic left atrial (LA) pressure overload and rheumatic inflammation cause subclinical atrial remodeling even without severe valvular stenosis. This study intended to determine whether advanced atrial deformation parameters identify patients with increased risk of atrial fibrillation (AF) from mild rheumatic mitral stenosis (MS). A prospective cohort study of patients with mild rheumatic MS and sinus rhythm was conducted in Baghdad, Iraq. LA Reservoir Strain (LASr) and LA Mechanical Dispersion (LAMD) were calculated via two-dimensional strain echocardiography at baseline. Patients were followed up for at least 2 years. The primary outcome was the occurrence of AF. Of 211 patients, 39 were found to have new-onset AF. The two strain parameters remained independent predictors of new-onset AF on multivariable Cox proportional hazards regression analysis. New AF occurrence was positively correlated with LAMD (adjusted Hazard ratio [aHR]: 1.047 [95% confidence interval (CI): 1.02–1.06], P < 0.001) and inversely correlated with LASr (aHR: 0.848 [95% CI: 0.79–0.90], P < 0.001). The optimal thresholds for LAMD and LASr for predicting new AF were >58.7 ms and ≤16.6%, respectively, which were defined by the Receiver Operating Characteristic curve. The presence of subclinical electromechanical dysfunction is an independent predictor of AF in mild rheumatic MS. Recognizing this high-risk phenotype supports closer ambulatory rhythm monitoring to allow timely arrhythmia detection and subsequent initiation of anticoagulation to prevent thromboembolic events.