Abstract 12358: Oral Iron Supplementation is Associated With Lower Pulmonary Vascular Resistance in Patients With Pulmonary Hypertension and Heart Failure With Preserved Ejection Fraction

Abstract

Introduction: Pulmonary hypertension (PH) associated with left heart disease can be stratified as isolated post-capillary (IpcPH) or combined pre and postcapillary (CpcPH) on the basis of a normal or elevated pulmonary vascular resistance (PVR). While CpcPH carries a poor prognosis, the mechanistic determinants of PVR in this population remain undefined. We hypothesize that discrepant medication usage between hemodynamic extremes of IpcPH and CpcPH may underlie this phenotypic divergence. Methods: Invasive hemodynamics were obtained at UPMC between 2008 and 2018. 4,567 patients met diagnostic criteria for Group 2 PH (mean pulmonary artery pressure [mPAP] ≥ 25mmHg, pulmonary artery wedge pressure [PAWP] > 15mmHg) based on the 2013 definition. Patients were classified as having extreme IpcPH (PVR<2WU, N=414) or CpcPH (PVR>4WU, N=172). Patients with overlapping PH diagnoses were excluded. Preserved ejection fraction was defined as a left ventricular EF >40%. Follow-up analyses were conducted on an independent set of PH-HFpEF patients with two RHCs more than 90 days apart inclusive of all PVRs (N=46). Results: Compared to IpcPH (N=127), patients with CpcPH (N=47) were prescribed anticoagulants (53.19 vs. 19.69%, p<0.001) more frequently and oral iron supplements less frequently (4.26 vs. 20.47%, p=0.010). Red cell distribution width (RDW), a marker of iron deficiency, was significantly higher in CpcPH (16.57 vs. 15.24%, p=0.007). In PH-HFpEF patients with successive RHCs, change in PVR correlated positively with change in RDW (p=0.002). Compared to iron naïve patients (N=30), iron initiation (N=7) between RHCs was associated with a lower change in PVR (-1.05 vs. +0.66WU, p=0.008). Conclusions: In a PH-HFpEF cohort, iron supplementation was associated with lower PVR, suggesting that iron deficiency may contribute to vascular remodeling in PH-HFpEF.