Related Experiment Video
Updated: Dec 14, 2025
Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats
Published on: June 28, 2019
A novel method for measuring absolute coronary blood flow and microvascular resistance in patients with ischaemic
Paul D Morris1,2,3, Rebecca Gosling1,2,3, Iwona Zwierzak1,3
1Mathematical Modelling in Medicine Group, Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield , UK.
Insights
A new computational fluid dynamics (CFD) method accurately measures absolute coronary blood flow and microvascular resistance (MVR) in the catheter lab, improving diagnosis of ischaemic heart disease.
Area of Science:
- Cardiovascular Physiology
- Medical Imaging
- Computational Fluid Dynamics
Background:
- Ischaemic heart disease involves reduced myocardial blood flow due to epicardial or microvascular issues.
- Current assessment using Fractional Flow Reserve (FFR) is limited, assessing only percentage flow changes and not absolute flow or microvascular disease.
- Distinct management strategies exist for epicardial and microvascular coronary disease.
Purpose of the Study:
- To develop and validate a novel computational fluid dynamics (CFD) model for predicting absolute coronary blood flow and microvascular resistance (MVR).
- To enable comprehensive physiological assessment within the catheter laboratory setting.
- To differentiate and quantify both epicardial and microvascular coronary artery disease.
Main Methods:
- A CFD model was developed to predict absolute coronary flow (QCFD) and MVR using routine invasive angiography and pressure-wire data.
- The QCFD model was validated using an in vitro flow circuit with patient-specific 3D-printed coronary arteries.
- In vivo validation was performed in 40 patients with coronary disease, assessing QCFD and MVR under baseline and hyperaemic conditions.
Main Results:
- In vitro validation showed close agreement between QCFD and experimental flow (R² = 0.999).
- In vivo, QCFD and MVR were successfully computed in all patients, enabling calculation of coronary flow reserve (CFR).
- QCFD-derived CFR strongly correlated with pressure-derived CFR (R² = 0.92), and the method proved significantly more accurate than Doppler-wire flow.
Conclusions:
- Absolute coronary flow and MVR can be determined non-invasively during routine catheter laboratory procedures.
- This novel method allows for the discrimination and quantification of both epicardial and microvascular coronary artery disease.
- Comprehensive coronary physiological assessment using this technique may enhance patient stratification and management.
Aims:
Ischaemic heart disease is the reduction of myocardial blood flow, caused by epicardial and/or microvascular disease. Both are common and prognostically important conditions, with distinct guideline-indicated management. Fractional flow reserve (FFR) is the current gold-standard assessment of epicardial coronary disease but is only a surrogate of flow and only predicts percentage flow changes. It cannot assess absolute (volumetric) flow or microvascular disease. The aim of this study was to develop and validate a novel method that predicts absolute coronary blood flow and microvascular resistance (MVR) in the catheter laboratory.
Methods And Results:
A computational fluid dynamics (CFD) model was used to predict absolute coronary flow (QCFD) and coronary MVR using data from routine invasive angiography and pressure-wire assessment. QCFD was validated in an in vitro flow circuit which incorporated patient-specific, three-dimensional printed coronary arteries; and then in vivo, in patients with coronary disease. In vitro, QCFD agreed closely with the experimental flow over all flow rates [bias +2.08 mL/min; 95% confidence interval (error range) -4.7 to +8.8 mL/min; R2 = 0.999, P < 0.001; variability coefficient <1%]. In vivo, QCFD and MVR were successfully computed in all 40 patients under baseline and hyperaemic conditions, from which coronary flow reserve (CFR) was also calculated. QCFD-derived CFR correlated closely with pressure-derived CFR (R2 = 0.92, P < 0.001). This novel method was significantly more accurate than Doppler-wire-derived flow both in vitro (±6.7 vs. ±34 mL/min) and in vivo (±0.9 vs. ±24.4 mmHg).
Conclusions:
Absolute coronary flow and MVR can be determined alongside FFR, in absolute units, during routine catheter laboratory assessment, without the need for additional catheters, wires or drug infusions. Using this novel method, epicardial and microvascular disease can be discriminated and quantified. This comprehensive coronary physiological assessment may enable a new level of patient stratification and management.
