We read with great interest the article by Kawut et al. regarding the clinical risk factors for portopulmonary hypertension (PPHTN) in a multicenter case-control epidemiologic study. 1 The authors demonstrated that women with liver disease have a higher risk than men of developing PPHTN. They have also showed that the cause of liver disease is important in determining the risk of this serious pulmonary vascular complication.
In a series of 90 outpatients with cirrhosis without portal thrombosis, we evaluated the presence of PPHTN by right heart catheterization with a Swan-Ganz catheter under fluoroscopic guidance and analyzed the relationship between hemodynamic parameters and the cause of liver disease. Patients showed a mean age of 52 years (19-72); 60 patients were Child-Pugh class A, 18 class B, and 12 class C. The study methodology was described elsewhere. 2 Eight of 90 patients showed mean pulmonary artery pressure (mPAP) higher than 25 mmHg. However, only two patients fulfilled the criteria of PPHTN as described by Kawut et al. 1 Therefore, the prevalence of this entity in our population was 2.2%. Interestingly, the two patients with PPHTN were young women, aged 19 and 30 years, respectively, having autoimmune hepatitis. In the whole sample, patients with autoimmune hepatitis or primary biliary cirrhosis were mostly women (13/15), and they were younger [44 Ϯ 15 standard deviations (SD) versus 54 Ϯ 9 SD years; P ϭ 0.001] and showed higher mPAP (22.5 Ϯ 8.8 SD versus 17.9 Ϯ 7.2 SD mmHg; P ϭ 0.03) and pulmonary vascular resistance (246 Ϯ 209 SD versus143 Ϯ 63 SD dyn ⅐ second/cm 5 ; P ϭ 0.008) than patients with cirrhosis of other causes (Table 1). In addition, pulmonary vascular resistance was significantly higher in women compared with men (193.5 Ϯ 161.9 SD versus 133.4 Ϯ 58.9 SD SD dyn ⅐ second/cm 5 , respectively, P Ͻ 0.05), regardless of the cause of liver disease. Conversely, patients with hepatitis C showed lower mPAP than other causes (16.3 Ϯ 5 SD versus 19.8 Ϯ 8 SD, P ϭ 0.04). No correlation was found between mPAP and other portal or systemic hemodynamic parameter or with severity of liver disease, but a negative correlation was found with age (r ϭ Ϫ0.28; P Ͻ 0.05).
In summary, in agreement with Kawut et al., we also observed that young women with autoimmune hepatitis might have an increased risk of developing PPHTN in comparison with patients with advanced liver disease of other causes. In addition, our patients with PPHTN showed lower scores of Child-Pugh classification, suggesting that the severity of liver disease is not a good predictor of PPHTN. Hence, these findings support the hypothesis that other factors nonrelated to hemodynamic changes present in portal hypertension and cirrhosis may play a role in the pathogenesis of PPHTN.