SummaryRecent studies have demonstrated elevations of von Willebrand Factor following acute myocardial infarction (AMI). In order to determine if this parameter may serve as a marker for AMI, we tested the blood levels of vWF and Factor VIII :C in 28 patients with AMI, 9 patients with unstable angina, 7 patients with atypical chest pain, and 25 healthy volunteers. The level of ristocetin cofactor activity of vWF was between 70 and 144% in the control group. In patients with AMI, the mean level of this activity was 175% on the first day following infarction, rose to a peak of 270% on the fifth and sixth days, and was still significantly greater than normal in all patients on the 14th day. The vWF: Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. FVIII :C was not significantly changed. No significant elevation of vWF was observed in patients with unstable angina. The ristocetin cofactor activity of vWF and vWF: Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels.

SummaryThe 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.

No abstract

No abstract

No abstract