Abstract 10541: Borderline Elevated Pulmonary Artery Pressures Not Meeting Criteria for Pulmonary Hypertension in Patients With Idiopathic Pulmonary Fibrosis is Associated With Lower Transplant-Free Survival

Abstract

Introduction: Pulmonary hypertension (PH) in Idiopathic Pulmonary Fibrosis (IPF) is associated with poor outcomes. The hemodynamic definition of PH was revised from a mean pulmonary artery pressure (mPAP) ≥25 mmHg to >20 mmHg. We sought to explore the implications of these criteria in patients with IPF with a focus on outcomes in those with an elevated mPAP not meeting criteria for Pre- or Post-capillary PH, herein termed Borderline PH. Methods: We identified patients with IPF who underwent chest CT, transthoracic echocardiography (TTE), and right heart catheterization (RHC) using the Mass General Brigham Research Patient Data Repository. Medical records were reviewed to confirm the diagnosis of IPF. Established hemodynamic criteria categorized patients by PH status. Patients with elevated mPAP >20 mmHg not meeting the definition of Pre-capillary PH (PVR ≥3 Wood Units) or Post-capillary PH (PCWP ≥15 mmHg) were defined as Borderline PH. Categorical variables were assessed using Chi-squared, Continuous variables using Wilcoxon Rank-Sum, and transplant-free survival using Kaplan-Meier analysis and Gehan-Breslow-Wilcoxon test. Results: 212 patients were identified: PH Present (n=92), Borderline PH (n=45), and PH Absent (n=75). One year from RHC, transplant-free survival was lower in patients with PH Present (n=37/92, 40%; p = 0.0002) or Borderline PH (n=20/45, 45%; p = 0.009) compared to those without PH (n=49/75, 65%) (Figure 1). Additionally, patients with Borderline PH had lower Pulmonary Artery Pulsatility Index (3.6 (3.0-6.0) vs 6.5 (4.2-10.5); p < 0.001), Pulmonary Artery Compliance (3.9 (3.2-4.6) vs 4.5 (3.4-5.8) mL/mmHg; p = 0.012), and an elevated Right Ventricular Stroke Work Index (9.9 (8.5-11.6) vs 7.3 (5.7-8.7) mmHg*mL/m 2 ; p < 0.001) versus those without PH. Conclusions: In this retrospective study of patients with IPF, those with Borderline PH had lower rates of transplant-free survival and worse derived hemodynamics compared to those without PH.