Diagnostic Accuracy Of CaFFR In Moderate To Severe Stenosis Lesions Of The Left Anterior Descending Artery

Objective:Fractional flow reserve(FFR)is a gold standard for coronary artery function,but the limitations of trans-pressure guidewire FFR have limited its widespread use in clinical practice.The coronary angiography-derived fractional flow reserve(caFFR)can compensate for some of the shortcomings of FFR,and studies have demonstrated the diagnostic performance of caFFR.The left anterior descending artery(LAD)has a high probability of atherosclerosis and a large myocardial supply,and differences between coronary angiography and the corresponding assessment of disease severity are more common in LAD lesions than in non-LAD lesions.There is a lack of studies on the diagnostic accuracy of caFFR in LAD.Using FFR results as the gold standard,this study further investigates the diagnostic accuracy of caFFR in LAD based on validating the diagnostic accuracy of overall caFFR in determining functional ischaemia in moderate to severe stenotic lesions in the coronary arteries.Methods:A total of 114 patients who underwent coronary angiography(CAG)and underwent trans-pressure guidewire FFR and were hospitalized in our cardiology department from September 2019 to July 2022 were retrospectively collected.The patients were divided into LAD and non-LAD groups according to the target vessel.0.80 was used as the threshold for diagnosing coronary ischemia for both FFR and caFFR to investigate the diagnostic accuracy of caFFR in the overall,LAD and non-LAD groups.Data were processed and analysed using SPSS Statistics 27.0 and Graph Pad Prism 9.0 statistical application software,and differences were considered statistically significant at P<0.05.Results:1.caFFR and FFR had good agreement[mean difference of-0.01,95%Limits of Agreement(Lo A):-0.16～0.14,P<0.001]and correlation[rs=0.640,95%Confidence Interval(Confidence Interval,CI):0.521～0.734,P<0.001].2.Using 0.80 as the diagnostic threshold,the accuracy of caFFR in diagnosing functional coronary ischemia was 90.7%(95%CI:90.6%～90.8%),91.0%(95%CI:90.8%～91.2%)and 90.0%(95%CI:89.6%～90.4%)in the overall,LAD and non-LAD groups,respectively.3.The optimal cut-off values of 0.795 and 0.800 for the overall and LAD groups,respectively,were consistent with the FFR diagnostic threshold,and the diagnostic performance was also consistent with that when FFR≤0.80 was used as the diagnostic threshold;the optimal cut-off value of 0.770 for the non-LAD group improved the diagnostic accuracy of caFFR to 92.5%(95%CI:92.2%～92.8%)when caFFR≤0.770was used as the threshold for functional coronary ischemia.Although the diagnostic accuracy of caFFR in the LAD group differed from that in the non-LAD group,the difference in diagnostic accuracy between the two groups was not statistically significant(x~2=0.078,P=0.779).Conclusions:1.caFFR has good agreement and correlation with FFR;2.caFFR has good diagnostic accuracy for moderate to severe stenotic lesions in overall,LAD and non-LAD vessels,and it can be used as an option for diagnosing functional coronary ischaemia.3.The use of 0.77 as the threshold for diagnosing ischaemia in the non-LAD group may go some way to reducing the burden on patients by reducing unnecessary coronary interventions.