Prevalence of Portal Hypertension in a Cohort of Patients With Group 1 and 4 Pulmonary Hypertension

Introduction: Pulmonary hypertension (PH) increases the risk of liver dysfunction secondary to congestive hepatopathy. Liver dysfunction and portal hypertension (PHT) manifest as periportal fibrosis, bridging fibrosis, and cirrhosis, respectively. Markers of liver dysfunction include thrombocytopenia, transaminitis, and hyperbilirubinemia, with direct bilirubinemia conferring increased mortality in patients with PH. This study aims to define the prevalence of PHT in patients with Group 1 and Group 4 PH. Methods: This was a case control study from a single tertiary institution analyzing 69 patients with a confirmed hemodynamic diagnosis of Group 1 or 4 PH. To assess PHT, the primary outcome measure was a platelet count < 150ug/ml. Secondary outcome measures included fibrosis-4 (FIB-4) and AST to platelet ratio index (APRI) scoring. Patients with missing data on any of the key variables or prior diagnoses of infectious or autoimmune hepatitis, alcohol use disorder, congenital heart or hematologic disease, or liver transplant were excluded from analyses. Fisher's exact tests were employed to assess the association between PH and PHT, with further stratification of the primary outcome measure by PH pharmacologic treatment class. Results: Demographics revealed a predominance of females at 67.1%, an average age of 57.3±15 years, 50% identifying as black. Ten patients had a platelet level < 150ug/ml. 26 patients fell into the indeterminant range for FIB-4 (1.45-3.25), while 4 patients scored >3.25, indicating advanced fibrosis. Five patients were positive for significant fibrosis by APRI with scores > 0.7. 3 patients had significant fibrosis without a platelet count< 150ug/ml. There was no significant effect on platelet level dependent on PH therapy: phophodiesterase–5 inhibitors, endothelin receptor antagonists, or prostacyclins (see Table 1). Conclusion: Among individuals with Group 1 or 4 PH, there were no statistically significant differences in the odds of developing PHT based upon the presence of risk factors, platelet count, FIB-4, and APRI scores or based on PH treatment class. Large-scale studies, including transient elastography, need to be undertaken to understand the link between PH and PHT. Table 1. - Platelet Count by PAH Treatment Class Prevalence Odds ratio for Plt < 150 Endothelin receptor antagonists (36, 51.4%) 1.106 Prostacyclin/prostanoid agonists (20, 28.6%) 0.945 Phosphodiesterase inhibitors/soluble GMP stimulators (60, 85.7%) 0.621