von Willebrand factor independently predicts long-term survival in patients with pulmonary arterial hypertension.
OBJECTIVE
We hypothesized that higher plasma levels of von Willebrand factor (vWF) and reduced ristocetin cofactor activity (RCA)/vWF ratios at baseline and follow-up would be associated with an increased risk of death in patients with pulmonary arterial hypertension (PAH).


BACKGROUND
Endothelial injury and dysfunction cause increased vWF levels in patients with cardiovascular disease. Increased vWF is associated with a higher risk of death in patients with coronary artery disease, congestive heart failure, and ARDS. In PAH, vWF is elevated and functions abnormally, resulting in reduced platelet binding. The ability of vWF to bind platelets is reflected by RCA.


METHODS
We performed a retrospective cohort study of 66 PAH patients who underwent initial evaluation at our center from January 1994 to June 2002. The primary outcome was death or lung transplantation.


RESULTS
vWF level was directly associated with Factor VIII activity, RCA, fibrinogen, and prothrombin time (p < or = 0.01). vWF levels at baseline and follow-up were associated with the risk of death (hazard ratio [HR] per 50% increase, 1.4; 95% confidence interval [CI], 1.1 to 1.8 [p = 0.02]; and HR per 50% increase, 1.5; 95% CI, 1.1 to 2.0 [p = 0.011]; n = 48, respectively). RCA/vWF ratios were not associated with outcome. These results were unaffected by adjustment for demographics, baseline hemodynamics, laboratory results, or PAH therapy in multivariate analyses.


CONCLUSIONS
Increased vWF levels at baseline and follow-up are associated with worse survival in patients with PAH; however, RCA/vWF ratios are not. The hemostatic effects of vWF do not account for these findings. This suggests that endothelial injury and dysfunction may persist despite treatment and may impact on disease course. Therapies that target endothelial injury may therefore improve outcomes for patients with PAH.
Kawut
Steven M
SM
Department of Medicine, College of Physicians and Surgeons, Joseph L. Mailma School of Public Health, Columbia University, New York, NY, USA. sk2097@columbia.edu
Horn
Evelyn M
EM
Berekashvili
Ketevan K
KK
Widlitz
Allison C
AC
Rosenzweig
Erika B
EB
Barst
Robyn J
RJ
D000328:Adult; D015331:Cohort Studies; D005169:Factor VIII / Q000032:analysis; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology* / Q000601:surgery; D016040:Lung Transplantation / Q000502:physiology; D008297:Male; D010973:Platelet Adhesiveness; D012189:Retrospective Studies; D017741:Survivors; D014841:von Willebrand Factor / Q000032:analysis*
D014841:von Willebrand Factor; D005169:Factor VIII