Coagulation activity is increased in the left atrium of patients with mitral stenosis

Objectives. This study investigated the hemostatic status of the right and left atri in patients with mitral stenosis. Background. Systemic thromboembolism is serious major complication in patients with mitral stenosis. However, the pathogenesis of thromboembolism in mitral stenosis is not fully understood. Methods. We determined the plasm levels of biochemical markers for platelet activity (platelet factor 4 and beta-thromboglobulin) and status of thrombin generation (fibrinopeptide and thrombin—antithrombin III complex) and fibrinolysis (D-dimer and plasmin—alpha2-plasmin inhibitor complex) in specimens of blood obtained from the peripheral vein and right and left atri of 12 consecutive patients with mitral stenosis who were undergoing percutaneous mitral valvuloplasty. Results. Plasm levels of platelet factor 4, beta-thromboglobulin, D-dimer and plasmin—alpha2-plasmin inhibitor complex in the patients did not differ significantly between the right and left atria, whereas levels of fibrinopeptide and thrombin-antithrombin III complex in the left atrium were significantly higher than those in the right atrium (fibrinopeptide in the left and right atri 19.35 ± 4.64 and 6.31 ± 0.75 ng/ml [mean ± SE], respectively, p < 0.02; thrombin-antithrombin III complex in the left and right atri 11.45 ± 2.29 and 3.98 ± 0.60 ng/ml, respectively, p < 0.01). Levels of fibrinopeptide and thrombin-antithrombin III complex in the left atrium did not correlate with mean transmitral gradient, dimension of the left atrium or reciprocal of the mitral valve area. Peripheral blood plasm levels of von Willebrand factor antigen were significantly higher in the patients than in an age-matched control group of normal subjects (168 ± 25% and 99 ± 7%, respectively, p < 0.05) but showed no difference in the peripheral blood and right and left atri of the patients. Conclusions. The coagulation system is activated in the left atrium of patients with mitral stenosis even during anticoagulation.