An Automated User-friendly Software for Fast Computation of Blood Flow Velocity From Coronary Angiographic Images

Area of Science:

• Cardiovascular Imaging
• Medical Software Development
• Hemodynamics

Background:

• Thrombolysis in Myocardial Infarction (TIMI) frame count assesses coronary flow but not coronary flow velocity (CFV).
• CFV is crucial for evaluating microvascular function, a key aspect of cardiovascular health.
• Existing methods for CFV measurement are limited, necessitating improved techniques.

Purpose of the Study:

• To introduce and validate a semi-automated software for rapid CFV computation using contrast bolus tracking in angiography.
• To compare the software's performance in CFV measurement against expert cardiologists.
• To assess the reproducibility and accuracy of the software-based CFV estimations.

Main Methods:

• Development of a semi-automated software utilizing contrast bolus tracking in coronary angiography for CFV calculation.
• Inclusion of 123 patients (152 vessels) undergoing coronary angiography.
• Comparative analysis of software-derived CFV measurements against those obtained by two expert cardiologists, with repeated measurements across varying segment lengths and projections.

Main Results:

• The software demonstrated excellent reproducibility in CFV measurement (ICC=.995), surpassing expert reproducibility (ICC=.946).
• Software estimations remained consistent across different segment lengths (ICC=.992), unlike experts who overestimated CFV in shorter segments.
• Moderate agreement was observed between software and expert measurements across different projections (ICC=.790-.807), and between experts (ICC=.885).

Conclusions:

• The developed semi-automated software provides highly reproducible coronary flow velocity estimations.
• The software's performance is comparable and in some aspects superior to expert assessments, particularly regarding segment length variability.
• Further validation against gold-standard wire-based functional techniques is recommended to confirm its utility in assessing microvascular function.