Inverse relation between Mitral Regurgitation Grade and the risk of stroke among patients with Atrial Fibrillation and Heart Failure

Background: Significant mitral regurgitation (MR) has been shown to reduce spontaneous echo contrast but its effect on the occurrence of ischemic stroke remains speculative.

Objective: To validate the long-term risk of ischemic stroke among patients with heart failure and known atrial fibrillation (AF) with and without MR.

Methods: We investigated 2,825 patients with known AF hospitalized at the Sheba Medical Center for acute decompensated heart failure. All patients had echocardiography performed during hospital stay. Patients were divided into 5 groups based on MR degree (0-IV). The primary end point was ischemic stroke during long term follow-up.

Results: Mean age of the study population was 79±11 years, of whom 48% were women. During a mean follow-up of 2 years, 317 (11.2%) events of ischemic stroke occurred. Kaplan-Meier survival analysis found that patients with MR grade 3-4 had significantly lower rates of stroke compared to patients with grade 0-2 (p-value log-rank=0.004). Multivariate cox regression showed that each increase in MR severity grade was associated with a 14% risk reduction in long term risk of stroke (HR 0.86 CI 0.75-0.98, p=0.03) despite adjustment for CHA₂DS₂VASC, anti-coagulation use and left atrial area.

Conclusions: In patients with heart failure and AF mitral regurgitation

is associated with a reduced risk of ischemic stroke.