Immediate effect of balloon valvuloplasty on hemostatic changes in mitral stenosis

This study was conducted to assess right and left atrial hemostatic function in patients with mitral stenosis (MS) and to investigate the immediate effect of balloon mitral valvuloplasty (BMV) on hemostatic function. BMV was performed in 28 patients with MS (age 29 ± 8 years) who had sinus rhythm and no left atrial (LA) thrombus. Right and left atrial biochemical markers of platelet activity (platelet factor 4 [PF4] and B thromboglobulin [BTG]), coagulation (thrombin-antithrombin III complex [TAT]), and fibrinolytic activity (D-dimer) were measured before and 30 minutes after BMV. Right atrial levels of these markers were also measured in 20 control subjects. Compared with control subjects, patients with MS had higher right atrial levels of PF4 (30 ± 15 vs 5 ± 2 IU/ml), BTG (231 ± 53 vs 30 ± 8 IU/ml), TAT (7 ± 4 vs 2 ± 0.3 μg/L), and D-dimer (380 ± 145 vs 160 ± 35 ng/ml, p <0.0001 in all). TAT levels were higher in the left atrium than in the right atrium of patients before BMV (8 ± 4 vs 7 ± 4 μg/L, p <0.0001). BMV was successful (final mitral valve area ≥1.5 cm2 and ≥50% increase of the initial valve area) in all patients. There was a significant reduction of LA levels of PF4 (35 ± 8 to 26 ± 9 IU/ml, p <0.0001), BTG (225 ± 41 to 196 ± 28 IU/ml, p <0.001), and TAT (10 ± 5 to 7 ± 1 μg/L, p <0.05) in the 16 patients with LA pressure <10 mm Hg after BMV, whereas these markers were not reduced in the 12 patients with left atrial pressure ≥10 mm Hg after BMV. These data indicate that platelet function, coagulation status, and fibrinolytic activity are increased regionally in the left atrium and in the systemic circulation in patients with MS and sinus rhythm in the absence of LA thrombus. Successful BMV induces a significant reduction of prethrombotic status in patients with low LA pressure after the procedure. Patients with high LA pressure after BMV maintain a high prethrombotic state and may be considered at an increased risk of thromboembolism after the procedure.