Abstract 11401: Silent Brain Infarct on MRI Predicts Clinical Stroke/ Transient Ischemic Attack in Mitral Stenosis

Abstract

Introduction: Mitral stenosis (MS) is associated with a high risk of cardio-embolic events. However, current recommendations for initiating anti-coagulant therapy in patients with MS is limited to patients with atrial fibrillation (AF),atrial thrombi or those with a prior stroke. In patients with moderate to severe MS who are in sinus rhythm there are no firm recommendations for anti-coagulation despite a known higher risk of thromboembolic events. Moreover there is limited data on the prevalence of silent brain infarcts (SBI) in patients with MS. This study evaluated prevalence and predictors of silent and clinical stroke in MS. Methods: A total of 211 patients with moderate to severe MS (mitral valve area ≤ 1.5 cm2) were recruited in the study and were followed up over a7 year period. Patients with existing left atrial clot(s) or prior valvular intervention were excluded from the study. All patients underwent clinical examination, ECG, echocardiogram, and brain MRI on a 1.5T machine. A 24-hour Holter was performed on patients in sinus rhythm. Results: Among 211 patients, 87(41.2%) were male and 140 (66.3%)were in sinus rhythm. Moderate to severe mitral regurgitation and/or aortic regurgitation was present in 31 (14.7%) and 30 (14.2%)patients respectively. SBI was seen in 44 (20.9 %) patients [26 (18.6%)in sinus rhythm and 18(25.4%) in AF]. Female gender (OR 2.3 95% CI 1.01-5.1, p = 0.043), poorer NYHA functional class (Class II OR 16, 95%CI 4.1-62.8, p=0.001; Class III OR 4.1 95%CI 1.2-13.8, p = 0.024),AF (OR 3.8 95%CI 1.6-8.9 p = 0.002) and aortic regurgitation (OR 3.7 95%CI 1.3-10.4 p = 0.011)were associated with increased risk of SBI. Seventeen patients (8%) were lost to follow up. Among 194patients who completed follow up, clinical stroke/TIA occurred in 15 (7.7%) patients. SBI on MRI was associated with a higher risk of clinical stroke/TIA on follow up on multivariate analysis (OR 3.7 95%CI1.26-10.9, p=0.018). Conclusions: Silent brain infarction is present in a significant minority of patients with MS and is predictive of clinical stroke/TIA on follow up.