Correction of acquired von Willebrand syndrome by transcatheter aortic valve implantation

AIMS: Acquired von Willebrand syndrome (aVWS) is a common complication of severe aortic valve stenosis and can be corrected by surgical valve replacement. Transcatheter aortic valve implantation (TAVI) is gaining importance, but the influence of this new technique on aVWS has never been examined. The objective of this study was to assess the impact of TAVI on aVWS.

METHODS: We enrolled 15 patients with severe aortic stenosis and high surgical risk admitted for elective TAVI. All patients were successfully treated by TAVI, using either the transfemoral (n = 6) or transapical approach (n = 9). Patients were screened for aVWS by measuring PFA-100 in vitro closure time, von Willebrand factor (VWF) antigen, VWF function, and VWF multimer analysis. Analyses were then repeated 30 minutes, 24 hours, and 7 days after valve replacement.

RESULTS: Fourteen of 15 patients showed pathologic alterations of VWF. An inverse correlation was observed between the transvalvular pressure gradient and VWF high-molecular-weight multimers (VWF:HMWM) (r = -0.621; P=.01), which are essential for the platelet dependent hemostatic function of VWF. Transaortic gradient was significantly reduced in all patients following TAVI. Hemostaseologic findings improved in all patients following TAVI, the percentage of VWF:HMWM increased (19.05 ± 5.19% before TAVI to 24.08 ± 4.75% (P=.04) on day 7 post TAVI), and the multimer pattern normalized.

CONCLUSIONS: Acquired von Willebrand syndrome due to aortic valve stenosis can successfully be corrected by TAVI.