Objective:To evaluate the correlation and consistency between quantitative coronary flow fraction (QFR) and cardiac magnetic resonance imaging (CMR) in assessing myocardial ischemia in patients with coronary heart disease (CAD).Methods:A retrospective analysis was conducted on the data of coronary heart disease patients who underwent load CMR examination and coronary angiography at the Beijing Anzhen Hospital, Capital Medical University from August 2017 to March 2022. CMR examination includes cardiac cine, load/rest myocardial perfusion imaging, and delayed enhancement sequence. According to the results of CMR examination, the patient′s left ventricular myocardial segments were divided into normal segment group and abnormal segment group (further divided into ischemic segment group and infarcted segment group). On the basis of coronary angiography, an artificial intelligence based platform (AngioPlus system) was applied to calculate the preoperative coronary artery QFR value of patients undergoing percutaneous coronary intervention treatment. Kappa test was used to evaluate the consistency of QFR and CMR in diagnosing abnormal myocardium; Mann Whitney U test was used to compare the differences in QFR between groups; The receiver operating characteristic (ROC) curve was used to evaluate the efficacy of QFR in diagnosing abnormal myocardium; Spearman correlation analysis was used to clarify the relationship between myocardial infarction area and QFR value of the supplying coronary artery in patients.Results:Among the 70 CAD patients enrolled, there were 60 males and 10 females, aged (54.1±11.1)years. At the vascular level, the consistency between QFR and CMR in diagnosing myocardial injury (including ischemia and infarction) is moderate (Kappa value=0.514). The sensitivity and specificity of detecting abnormal myocardial segments in CAD patients were 57% and 91%, respectively. The area under the curve (AUC) value of QFR predicting abnormal myocardium in CAD patients was 0.769, and the optimal cutoff value was QFR=0.865. At this time, the sensitivity and specificity of QFR predicting myocardial injury in CAD patients were 67.2% and 84.3%, respectively. The difference in vascular QFR between the normal segment group, ischemic segment group, and infarcted segment group was statistically significant ( P<0.001), with the infarcted segment group having significantly lower QFR values than the other two groups (all P<0.01). The range of myocardial infarction was negatively correlated with the QFR value of the supplying coronary artery ( r=-0.45, P<0.001). At the patient level, the consistency between QFR and CMR in diagnosing myocardial injury (including ischemia and infarction) was moderate (Kappa value=0.445), with a sensitivity of 74% and a specificity of 81% for diagnosing myocardial injury in CAD patients. Conclusions:Compared with CMR, QFR has better specificity in detecting myocardial injury in CAD patients. The QFR value of the infarcted segment group is significantly lower than that of the ischemic group and the normal group. The area of myocardial infarction is negatively correlated with the QFR value of the supplying coronary artery.