Prognostic factors in patients with idiopathic portal hypertension: Two Japanese nationwide epidemiological surveys in 1999 and 2005

Aim: To investigate factors affecting disease prognosis among patients with idiopathic portal hypertension (IPH). Methods: Two Japanese nationwide epidemiological surveys on IPH were conducted in 1999 and 2005. Analyzing data from each cross-sectional survey separately, we examined the consistent prognostic factors detected from each analysis and assessed the effect of treatments for varices on IPH prognosis. Outcome was the disease condition at last observation compared with that at diagnosis, categorized into two levels (recovered/improved and unchanged/aggravated/deceased). To evaluate the association with each characteristic, we calculated adjusted odds ratio (OR) and 95% confidence interval (CI) using a binary model for logistic regression. Results: Among 160 patients with IPH in 1999 and 85 in 2005, 10% had aggravated disease at a mean of 6-7years after the diagnosis. Statistically significant ORs were observed for two factors: esophageal varices, especially of F_2-3 stage, at diagnosis (OR=6.83, 95% CI=2.10-22.1 in 1999; OR=10.7, 95% CI=1.08-105 in 2005) ameliorated IPH; and hepatic encephalopathy at diagnosis (OR=0.19, 95% CI=0.03-1.04 in 1999; crude OR=0.05, 95% CI=0.01-0.60 in 2005 using a proportional odds model) worsened IPH. Further analyses explained that the apparent ameliorating effect of esophageal varices was due to the effect of subsequent treatment (OR=4.59, 95% CI=0.89-23.7 in 2005). Conclusion: The prognosis of IPH would be better if varices were adequately controlled. Patients with liver failure at diagnosis would be at high risk for subsequent disease aggravation.