Relationship of cardiac MRI-derived pulmonary arterial stiffness markers and invasive hemodynamic

Pulmonary arterial stiffness (PAS) is a noninvasive imaging biomarker associated with disease severity in pulmonary hypertension (PH). This study aimed to evaluate PAS using cardiac magnetic resonance (CMR) imaging and investigate its relationship with hemodynamic parameters from right heart catheterization (RHC) across PH subgroups. In this retrospective study, 44 patients with PH who underwent both RHC and CMR were classified into pre-capillary (precapPH), post-capillary (postcapPH), and combined pre- and post-capillary (combPH) PH groups based on guideline-defined criteria. PAS was assessed by CMR-derived pulse wave velocity (PWV) and relative area change (RAC) of the main pulmonary artery. RHC measurements included mPAP, PVR, and right ventricular pressures and mixed venous saturation. PWV was significantly higher in combPH (4.49 ± 1.32 m/s) compared to precapPH (3.40 ± 0.98 m/s, p = 0.04). RAC was significantly lower in combPH (0.18 ± 0.11) than in postcapPH (0.28 ± 0.09), p = 0.01) and precapPH (0.18 ± 0.07, p = 0.01). PWV correlated with mPAP (r = 0.34, p = 0.022), RAP (r = 0.39, p = 0.008), and RVEDVi (r = 0.34, p = 0.022), while RAC showed a negative correlation with PVR (r = - 0.36, p = 0.01). Distinct RV adaptation patterns were observed among subgroups, with combPH patients exhibiting the most impaired hemodynamics. CMR-derived PAS indices correlate with invasive hemodynamic markers and differ among PH subtypes. PWV and RAC may serve as useful noninvasive markers for assessing pulmonary vascular burden and differentiating disease severity in PH. Larger prospective studies are needed to validate their clinical utility.