Integrating Invasive and Noninvasive Imaging for Coronary Atherosclerosis: A Systematic Review With Pragmatic...

Accurate detection and characterization of coronary atherosclerosis are essential for risk stratification and for guiding revascularization strategies. We aim to provide a pragmatic comparison of invasive and noninvasive imaging approaches for the detection, physiological assessment, and clinical management of coronary atherosclerosis. This review compares invasive techniques-coronary angiography, wire-based physiological assessment using fractional flow reserve (FFR) and instantaneous wave-free ratio, and intravascular imaging with intravascular ultrasound and optical coherence tomography - with noninvasive strategies including coronary artery calcium scoring, coronary computed tomography angiography (CCTA) with or without computed tomography - derived FFR, stress echocardiography, single-photon emission computed tomography, positron emission tomography (PET) with absolute myocardial blood flow quantification, and stress cardiovascular magnetic resonance imaging. We summarize diagnostic performance for anatomical plaque detection and ischemia assessment, strengths and limitations, patient selection considerations, safety issues related to radiation and contrast exposure, and downstream clinical impact. Invasive modalities remain the reference standard for lesion-level anatomical and physiological assessment when revascularization is contemplated. In contrast, noninvasive tests efficiently triage symptomatic patients, characterize plaque, and quantify ischemia and microvascular dysfunction. A pragmatic diagnostic algorithm integrates non-invasive anatomical or physiological testing as the initial step. It reserves invasive evaluation for high-risk findings or when percutaneous coronary intervention or coronary artery bypass grafting is likely. Future directions include refined plaque characterization on CCTA, quantitative PET perfusion imaging, computed tomography-derived FFR, and artificial intelligence-assisted image analysis.