Circulating von Willebrand Factor Antigen as a Predictor of Short-term Prognosis in Pulmonary Hypertension: The likelihood of fatal outcome
Eleven patients died during the first year of follow-up. Seven patients had primary pulmonary hypertension, and the remaining patients had either congenital heart disease (n = 3) or collagen vascular disease (n = 1). Survival was not influenced by patient age, sex, or mean pulmonary arterial pressure (Tables 1 and 2). However, the proportion of patients with primary pulmonary hypertension who died in the interval was significantly higher than that for patients with secondary pulmonary hypertension (p < 0.005, Table 1). In addition, the nonsurvivors had higher vWF:Ag values at the beginning of the follow-up period than the survivors, and this was highly significant (p < 0.0001, Table 2). In the subgroup of patients with secondary pulmonary hypertension, vWF:Ag was significantly higher in the nonsurvivors than in the survivors (247.5 ± 78.7% and 124.8 ± 58.3% activity, respectively; p < 0.05). In patients with primary pulmonary hypertension, a clear trend toward higher v\VF:Ag levels for the nonsurvivors also was observed (261.8 ± 94.6% activity for nonsurvivors vs 177.2 ± 49.7% activity for survivors). Thus, vWF:Ag values were similar for the nonsurviving patients from both subgroups (p = NS). Buy dexone online read more For the whole group of 40 patients, a vWF:Ag of > 240% (p = 0.003) was 54% sensitive for and 93% specific for identifying patients who were unlikely to survive 1 year, with an overall predictive value of 75%. The influence of plasma vWF:Ag levels on the likelihood of fatal outcome during the first year of follow-up in patients with primary and secondary pulmonary hypertension is shown in Figure 1. Multivariate analysis showed that the etiology of pulmonary hypertension (ie, primary vs secondary form) and plasma vWF:Ag levels influenced patient outcomes independently. The equation that represents the probability of death as a function of initial vWF:Ag values was:
where P and S are 0 and 1, respectively, for primary and secondary pulmonary hypertension.
Table 1—Correlation of Sex, Age, and Etiology of Pulmonary Hypertension With 1-Year Survival
|Variable||Category-||Deceased||Alive||p> x2||p, Fisher|
|Etiology of pulmonary hypertension||PPH*||7||4|
Table 2—Correlation of Age, Mean Pulmonary Arterial Pressure, and vWF:Ag with 1-Year Survival in Pulmonary Hypertension
|Variable||Status at 1 yr||n||Mean ± SD||Range||P(t test)|
|Age||Deceased||11||26.4 ± 13.7||3-43||0.2686|
|Alive||29||21.6 ± 11.5||1.2-45|
|Mean PAP* (mm Hg)||Deceased||11||70.3 ± 25.2||30-112||0.4720|
|Alive||29||64.8 ± 19.9||27-105|
|vWFAg (% activity)||Deceased||11||256.6 ± 85.3||141-379||<0.0001|
|Alive||29||132.0 ± 59.3||56-244|
Figure 1. The likelihood of fatal outcome in pulmonary hypertension as a function of plasma antigenic activity of vWF. Parameters for curve fitting were estimated by logistic regression analysis of data obtained from 11 primary (P) and 29 secondary (S) pulmonary hypertensive patients. The slope corresponding to the influence of vWF:Ag on the probability of death was 0.02 ± 0.01 (estimate, ± SEE; p = 0.0087). The odds ratio associated with vWF:Ag values was 1.022 with a 95% Cl of 1.01 to 1.04.