journal · The International Journal of Cardiovascular Imaging · 2025

Non-invasive derivation of instantaneous free-wave ratio from invasive coronary angiography using a new deep learning artificial intelligence model and comparison with human operators’ performance

Catarina Oliveira, Marta Vilela, João Silva Marques, Cláudia Jorge, Tiago Rodrigues, Ana Rita Francisco, Rita Marante de Oliveira, Beatríz Silva, João Lourenço Silva, Arlindo L. Oliveira, Fausto J. Pinto, Miguel Nobre Menezes · 1 citations

View original publication →

See where this sits in the topic map →

Summary AI-generated

TL;DR
This study develops and evaluates a deep learning model to non-invasively classify coronary lesions using standard angiography, comparing its performance against experienced human operators.
Problem
Invasive coronary physiology assessments are underused, costly, and carry patient risks, while non-invasive alternatives derived from angiography—particularly for the instantaneous wave-free ratio (iFR)—remain rarely explored.
Method
Using a single-center retrospective dataset, the researchers trained a validated encoder-decoder convolutional neural network to segment vessels and tested three AI models combining transformers and EfficientNet architectures to classify lesions as positive or negative.
Results
Across 250 measurements, the unified AI model achieved an overall accuracy of 72% and a high negative predictive value of 90%, significantly outperforming human operators in the left anterior descending artery (78% vs. 60–64%).
Contributions
The study successfully unifies specialized vessel-based AI models—combining transformer and convolutional neural network approaches—for binary iFR lesion classification using ten-fold patient-level cross-validation.
Limitations
Not specified in the abstract.
Takeaways
The proposed AI model mildly outperformed interventional cardiologists in binary iFR lesion classification, supporting the need for further validation studies.
Applications
Non-invasive physiological assessment of coronary lesions from standard invasive coronary angiography.
Topics
Healthcare, Artificial Intelligence, Deep Learning, Computer Vision, Cardiovascular Imaging
For industry
Healthcare and Medical Technology
Why it matters
Demonstrating that AI can match or outperform cardiologists in non-invasive coronary physiology assessment could help reduce the risks and costs associated with invasive procedures.

Abstract

Invasive coronary physiology is underused and carries risks/costs. Artificial Intelligence (AI) might enable non-invasive physiology from invasive coronary angiography (CAG), possibly outperforming humans, but has seldom been explored, especially for instantaneous wave-free Ratio (iFR). We aimed to develop binary iFR lesion classification AI models and compare them with human performance. single-center retrospective study of patients undergoing CAG and iFR. A validated encoder-decoder convolutional neural network (CNN) performed segmentation. Manual annotation of target vessel and pressure sensor location on a segmented telediastolic frame followed. Three AI models classified lesions as positive (≤ 0.89) or negative (> 0.89). Model 1 uses preprocessed vessel diameters with a transformer. Models 2/3 are EfficientNet-B5 CNNs using concatenated angiography and segmentation - Model 3 employs class-frequency-weighted Cross-Entropy Loss. Previous findings demonstrated Model 3's superiority for left anterior descending (LAD) and Model 1's for circumflex (Cx)/right coronary artery (RCA) - they were therefore unified into a vessel-based model. Ten-fold patient-level cross-validation enabled full sample training/testing. Three experienced operators performed binary iFR classification using single frames of raw/segmented images. Comparison metrics were accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Across 250 measurements, AI accuracy was 72%, PPV 48%, NPV 90%, sensitivity 77%, and specificity 71%. Human accuracy ranged from 54 to 74%. NPV was high for the Cx/RCA (AI: 96/98%; operators: 94/97%), but AI significantly outperformed humans in the LAD (78% vs. 60-64%). An AI model capable of binary iFR lesions classification mildly outperformed interventional cardiologists, supporting further validation studies.

References within the group

← All publications