Patient-Specific Computational Analysis of Hemodynamics in Adult Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive disease characterized by elevated pressure and vascular resistance in the pulmonary arteries. Nearly 250,000 hospitalizations occur annually in the US with PH as the primary or secondary condition. A definitive diagnosis of PH requires right heart catheterization (RHC) in addition to a chest computed tomography, a walking test, and others. While RHC is the gold standard for diagnosing PH, it is invasive and posseses inherent risks and contraindications. In this work, we characterized the patient-specific pulmonary hemodynamics in silico for diverse PH WHO groups. We grouped patients on the basis of mean pulmonary arterial pressure (mPAP) into three disease severity groups: at-risk ( $$18 {\text{mmHg}}\le {\text{mPAP}}<25 {\text{mmHg}}$$ , denoted with A), mild ( $$25 {\text{mmHg}}\le {\text{mPAP}}<40 {\text{mmHg}}$$ , denoted with M), and severe ( $${\text{mPAP}}\ge 40 {\text{mmHg}}$$ , denoted with S). The pulsatile flow hemodynamics was simulated by evaluating the three-dimensional Navier–Stokes system of equations using a flow solver developed by customizing OpenFOAM libraries (v5.0, The OpenFOAM Foundation). Quasi patient-specific boundary conditions were implemented using a Womersley inlet velocity profile and transient resistance outflow conditions. Hemodynamic indices such as spatially averaged wall shear stress ( $${\text{SAWSS}}$$ ), wall shear stress gradient ( $${\text{WSSG}}$$ ), time-averaged wall shear stress ( $${\text{TAWSS}}$$ ), oscillatory shear index ( $${\text{OSI}}$$ ), and relative residence time ( $${\text{RRT}}$$ ), were evaluated along with the clinical metrics pulmonary vascular resistance ( $${\text{PVR}}$$ ), stroke volume ( $${\text{SV}}$$ ) and compliance ( $$C$$ ), to assess possible spatiotemporal correlations. We observed statistically significant decreases in $${\text{SAWSS}}$$ , $${\text{WSSG}}$$ , and $${\text{TAWSS}}$$ , and increases in $${\text{OSI}}$$ and $${\text{RRT}}$$ with disease severity. $${\text{PVR}}$$ was moderately correlated with $${\text{SAWSS}}$$ and $${\text{RRT}}$$ at the mid-notch stage of the cardiac cycle when these indices were computed using the global pulmonary arterial geometry. These results are promising in the context of a long-term goal of identifying computational biomarkers that can serve as surrogates for invasive diagnostic protocols of PH.