Connectivity to Enable Accurate Patient-Specific Cardiovascular Assessments

Context Cardiovascular diseases (CVD) are the leading cause of death globally, responsible for around 1 in 3 deaths annually. The economic burden is significant, costing the NHS approximately £10 billion and the wider economy £25 billion each year. Fractional flow reserve (FFR) is the current gold standard for the assessment of coronary artery disease (CAD), the most common CVD. But it is invasive, time-consuming, expensive and risky. Accurate, non-invasive diagnostic tools such as virtual FFR (vFFR - VIRTUheart) and absolute coronary blood flow can improve patient outcomes and comfort, pathway efficiency and reduce costs. Challenges to be Addressed State-of-the-art diagnostic models, including VIRTUheart, face limitations in clinical deployment due to reconstruction instability (Objectives 1-2) but provide an ideal foundation for more comprehensive diagnostic metrics based upon improved and expanded physiological content (Objectives 3-5). Complex cases, characterised by very twisted vessels and inadequate contrast in 2D angiograms inter alia result in vFFR inaccuracies. These same inaccuracies obstruct the shift from the relative metric of vFFR to absolute flow for CAD assessment. Meanwhile, an ageing population with increasing prevalence of CAD is escalating the demand for rapid, efficient, scalable, and deployable diagnostic solutions. Objectives and Methods This pilot project will strengthen collaborations between computing engineer and mathematician Xu, consultant cardiologists Gunn and Morris, and medical physicist Halliday. It will also enable Xu to gain cardiology insight and deliver novel engineering and physical sciences (EPS) research from a clinical user perspective, addressing EPSRC health technologies’ ‘transforming prediction and early diagnosis’ challenge. We aim to refine and extend the current patient-specific VIRTUheart models with more accurate captures of anatomy and embedded physiology, for effective and efficient CAD assessment and treatment planning. The team seek to: Enhance tool geometry reconstruction and quantify uncertainty: Utilise digital and 3D-printed phantoms to validate and minimise errors in 3D artery reconstruction from 2D angiographic images. Quantify uncertainty in the models to produce predicted metrics with confidence bounds. Simulate contrast medium dynamics: Understand the impact of radio-opaque dye transport on angiography, using convection-diffusion models to predict angiographic image accuracy. Incorporate sequestration flow: Develop novel models to account for blood flow into unresolved side-branch vessels, modelled as a porous wall flux in 3D. Verify absolute distal flow as an alternative CAD diagnostic metric: Validate blood flow simulations against in vivo measurements to establish and verify the diagnostic reliability of absolute flow. Introduce pulsatility: Incorporate pulsatile blood flow effects into current VIRTUheart models. Develop and validate pulsatile flow boundary conditions using digital phantoms and quantify the diagnostic significance of temporal complex flow dynamics. Potential Applications and Benefits Multiple benefits stem from this project: (i) enhanced accuracy in detecting and assessing CAD, leading to better patient outcomes; (ii) more accurate vFFR calculations will reduce the need for invasive procedures and impacting costs, and increase accessibility and patient participation; (iii) advanced understanding of coronary anatomy and haemodynamics will support new treatment approaches and personalised interventions accounting for patient characteristics. The novel EPS research and techniques developed in this pilot project could be applied to other computational medicine areas modelling physiological flow, e.g. pulmonology, neurology, oncology and orthopaedics. We expect the project findings to inform clinical practice and national guidelines on the use of vFFR and establish regulatory standards for the accuracy and reliability of medical imaging and computational diagnostics - a step towards commercialisation.