Photon-counting CT (PCCT) was used to characterize suspected HeartMate 3 (HM3) left ventricular assist device (LVAD) outflow graft stenosis and generate patient-specific computational fluid dynamics (CFD) models to determine whether visually apparent stenoses were haemodynamically significant.
Despite radiological cross-sectional area reductions of 29–61%, simulated pressure gradients remained low (1–9 mmHg), suggesting that many asymptomatic patients with moderate extrinsic graft compression may not require immediate intervention. The study demonstrates that anatomical stenosis severity alone may overestimate functional obstruction.
PCCT was selected because of its improved spatial resolution, reduced metal artefacts, and superior contrast performance around metallic LVAD components, enabling accurate segmentation for CFD modelling.
