Increased platelet activation and endothelial dysfunction in patients withatrial fibrillation immediately following percutaneous balloon mitral valvuloplasty

Background: Immediately following percutaneous balloon mitral valvuloplasty (PBMVP), patients have a 3% risk of systemic thromboembolism. Hypothesis: We hypothesized that this may in part be due to an increase in hypercoagula bility (as indicated by abnormal coagulation, platelet activation, and endo thelial dysfunction) in such patients. Methods: We measured indices of platelet activation [soluble P-selectin (sP sel), ELISA], endothelial dysfunction [von Willebrand factor (vWf), ELISA], and coagulation (fibrinogen, modified Clauss) in 16 patients (15 women, me an age 59 +/- 10 years) with chronic atrial fibrillation admitted for PBMVP , and 16 healthy age- and gender-matched controls. Blood samples were obtai ned as follows: (1) peripheral venous samples prior to PBMVP, immediately f ollowing PBMVP, and 24 h after PBMVP: and (2) arterial samples prior to and immediately following PBMVP. Results: Patients with mitral stenosis and chronic atrial fibrillation demo nstrated significantly higher mean levels of vWf [148 (SD 24) vs. 102 (SD 3 7); t-test, p < 0.001] and plasma fibrinogen [4.2 (SD 0.8) vs. 3.3 (SD 0.8) ; p = 0.003] at baseline than matched healthy controls. There was a nonsign ificant trend toward lower median sP-sel levels in patients with mitral ste nosis [64 (inter quartile range 47-91) vs. 109 (46-128); Mann-Whitney test, p = 0.08]. Following PBMVP, there was a significant increase in venous sP- sel levels immediately post procedure (paired Wilcoxon test, p = 0.03) and at 24 h after ward (p = 0.01). Arterial s-Psel levels correspondingly incre ased immediately post procedure (p = 0.008). There was a significant increa se in mean venous (at 24 h) but not arterial vWf levels post PBMVP. There w ere no significant changes in mean venous or arterial plasma fibrinogen lev els following PBMVP. Conclusion: Patients with mitral stenosis and chronic atrial fibrillation h ave increased plasma levels of vWf and fibrinogen levels compared with heal thy controls, suggesting increased endothelial dysfunction and coagulation at baseline in these patients. The increased levels of sP-sel immediately p ost procedure and at 24 h, in association with increased vWf levels at 24 h after PBMVP, are in keeping with an increase in platelet activation and en dothelial dysfunction following PBMVP These changes may contribute to the i ncreased risk of thromboembolism following PBMVP and suggest the need for a dequate antithrombotic therapy following PBMVP.