Study on consistency of resting full-cycle ratio and fractional flow reserve

AIM To evaluate the agreement between resting full-cycle ratio (RFR) and fractional flow reserve (FFR) with the currently recommended thresholds.

METHODS The study included coronary heart disease patients undergoing invasive physiology check from September 2021 to September 2022 in our hospital. Comparison between RFR ≤0.89 and FFR ≤ 0.80 value was made to evaluate the sensitivity, specificity, positive predictive value and negative predictive value of RFR.

RESULTS A total of 189 lesions were evaluated in 138 patients. Significant correlation was observed (R²=0.629, P<0.01) between the two techniques, with 81.5% agreement between RFR ≤ 0.89 and FFR ≤ 0.80 (sensitivity 70.1%, specificity 87.7%, positive predictive value 75.8%, negative predictive value 84.3%, and accuracy 81.5%). The AUC area under the ROC curve was 0.889 (95%CI:0.842～0.937, P<0.01). The Youden index was 0.609.

CONCLUSION Significant agreement is found between RFR and FFR with the recommended thresholds and they can be used for coronary physiology assessment.