Related Experiment Video
Updated: May 5, 2026
06:39
Ultrasound Based Assessment of Coronary Artery Flow and Coronary Flow Reserve Using the Pressure Overload Model in Mice
Published on: April 13, 2015
15.1K
Unmasking Myocardial Bridge-Related Ischemia by Quantitative Flow Ratio Functional Evaluation
Francesco Cardaioli1, Tommaso Sciarretta1, Federico Arturi1
1Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua Medical School, Padua, Italy.
The American Journal of Cardiology
|September 6, 2025
Summary
Quantitative Flow Ratio (QFR) effectively detects myocardial bridge (MB) ischemia during stress, showing high sensitivity comparable to stress instantaneous wave-free ratio (iFR) and superior to stress fractional flow reserve (FFR). This minimally invasive approach aids in evaluating dynamic coronary stenosis.
Area of Science:
- Cardiology
- Interventional Cardiology
- Diagnostic Imaging
Background:
- Myocardial bridges (MBs) are increasingly recognized for their potential hemodynamic impact.
- Assessing the functional significance of MBs is crucial for patient management.
- Current invasive methods like FFR and iFR have limitations, necessitating alternative approaches.
Purpose of the Study:
- To compare the diagnostic efficacy of FFR, iFR, and QFR in evaluating MBs.
- To assess the utility of these indices at rest and under stress conditions.
- To determine if QFR can serve as a reliable, minimally invasive tool for MB assessment.
Main Methods:
- Inclusion of patients with confirmed LAD MB and ischemic symptoms.
- Intracoronary functional assessment using FFR and iFR at rest and during dobutamine/atropine stress.
- Calculation of QFR at rest and during dobutamine stress.
- Defining ischemia based on established FFR (≤0.80), iFR (≤0.89), and QFR (≤0.84) cutoffs.
Main Results:
- Stress iFR and stress QFR detected significant ischemia in 18 out of 21 patients, unlike FFR.
- Stress QFR demonstrated high sensitivity (0.86) for MB-related ischemia.
- Stress QFR and stress iFR showed strong concordance and correlation (ρ = 0.702, p = 0.037).
Conclusions:
- Stress QFR is a sensitive and reliable minimally invasive method for evaluating MB-related ischemia.
- QFR performance is comparable to stress iFR and superior to stress FFR in this context.
- Further research is needed to validate QFR for dynamic coronary stenosis assessment.
