Prevalence of silent brain lesions in rheumatic mitral valve disease

Patients with rheumatic heart disease (RHD) are at high risk of stroke. Silent brain lesions (SBL) on brain MRI represent subclinical neurological injury, but their prevalence and predictors in RHD are not well defined.

We conducted a prospective, single-center study of consecutive adults with RHD and moderate-to-severe mitral valve disease. Patients with a history of stroke, hypertension, diabetes, smoking, or ventricular dysfunction were excluded. All participants underwent a standardized protocol including clinical assessment, electrocardiography, echocardiography, and 3T brain MRI.

Among 79 patients (mean age 44.3 ± 11.4 years, 69.6% female), SBL were present in 14 (17.7%). Most patients (81%; n = 64) had atrial fibrillation (AF). The prevalence of SBL was similar between those with AF and those in sinus rhythm (17.2% vs. 20%). There were no significant differences in age, gender, valve lesion type (stenosis vs. regurgitation), left atrial size, or the presence of LAA thrombus between patients with and without SBL. The majority of SBL (85.7%) were located in cortical regions.

Silent brain lesions on MRI were detectable in 17.7% RHD patients with significant mitral valve disease, even in the absence of traditional stroke risk factors. We did not find any association between occurrence of these brain lesions and atrial fibrillation or left atrial enlargement. Alternative mechanisms like pro-thrombotic states or atrial cardiomyopathy may be responsible. These findings warrant further investigation into the clinical significance and management of subclinical brain injury in RHD.