Von Willebrand factor and mitral valve prolapse

The levels of von Willebrand factor (vWF:Ag) were measured in 27 patients with mitral valve prolapse (MVP) and compared to 27 age matched controls. Decreased levels of vWF:Ag (<80%) were found in 59% (16/27) of those with MVP compared to only 7% (2/27) of the controls (p < 0.001). Mean vWF:Ag levels were also significantly lower in those with MVP (68 ± 30% versus 100 ± 23%, p < 0.001). In those with MVP and congestive heart failure secondary to ruptured chordae tendineae, however, the mean level of vWF:Ag was not significantly different from control values (95 ± 32). There was an increased incidence of recurrent nose bleeds in those with MVP and low levels of vWF:Ag. We conclude that there is a relationship between MVP and low levels of vWF:Ag which may explain the increased incidence of epistaxis in such patients. Increased release of vWF:Ag in those with MVP and concomitant congestive heart failure may account for the normal levels found in this subgroup.