Clinical and Hemodynamic Factors Associated with Low Gradient Severe Rheumatic Mitral Stenosis

Background Discrepancy between narrowed mitral valve area and transmitral gradient is not uncommon, suggesting the presence of low gradient (LG)-severe mitral stenosis (MS). Some clinical and hemodynamic factors are believed to associate with LG-severe MS. Methods Transthoracic echocardiography reports were reviewed retrospectively to evaluate the association of all clinical and hemodynamic parameters with LG-severe MS. Results A 36% of total 322 patients was in the LG-severe MS group. In multivariate analysis, atrial fibrillation (95% confidence interval [CI] 4.60-16.71, odds ratio [OR] 8.77), net atrioventricular compliance > 4 mL/mm Hg (95% CI 3.96-14.25, OR 7.51), tricuspid regurgitation maximal velocity (TR Vmax) > 3.4 m/s (95% CI 0.13-0.48, OR 0.25), stroke volume index <= 35 mL/m(2) (95% CI 1.49-6.25, OR 3.05), female gender (95% CI 1.30-5.33, OR 2.63), and severe tricuspid regurgitation (95% CI 1.04-5.50, OR 2.39) were found to be associated with LG-severe MS. Conclusion Atrial fibrillation, net atrioventricular compliance, TR Vmax, stroke volume index, female gender, and severe TR were associated with low transmitral gradient in patients with severe MS.