Background: Significant mitral regurgitation (MR) is associated with less spontaneous echo contrast but its effect on the occurrence of ischemic stroke in patients with atrial fibrillation (AF) is unknown.
Objectives: To examine the association of MR grade and the risk of ischemic stroke (IS) in AF patients with heart failure (HF).
Methods: We investigated 2748 patients with known AF who were hospitalized due to acute decompensated HF. All patients underwent echocardiography during hospitalization. Patients were divided into groups based on the degree of MR (high-grade MR [3–4] vs. no/low-grade MR [0–2]). The primary endpoint was IS during long term follow-up.
Results: Mean age was 79 ± 11 years, 48% were women. After 2 years of follow-up, the cumulative incidence of IS among patients with high-grade MR was significantly lower compared to patients with no/low-grade MR (6% vs. 12%, respectively; P-value = 0.0064). Multivariate Fine and Gray analysis, adjusting for CHA₂DS₂-VASc, and accounting for the competing risk of death and valve intervention, showed the presence of high-grade MR was associated with a significant 50% (P = 0.013) reduction in the risk of IS compared with no/low-grade MR. When added to the CHA₂DS₂-VASc score, MR grade allowed more accurate prediction of IS with an overall improvement of 12% (95% confidence interval 5–17%) using net reclassification index analysis.
Conclusions: Our findings suggest an inverse correlation between MR grade and the risk of stroke among AF patients with HF. These findings may be used for improved risk assessment in this population.