Correlation Between Contrast Medium And Adenosine Triphosphate In Determination Of Fractional Flow Reserve

Objective: To analyse the correlation between contrast medium and adenosine triphosphate in the determination of fractional flow reserve,and to explore the feasibility of contrast-based FFR in the evaluation of intermediate coronary stenosis.Methods: Sixteen patients with coronary heart disease who underwent coronary angiography and FFR in the Department of Cardiology,Second Hospital of Hebei Medical University from March 2018 to March 2019 were enrolled.Coronary angiography and QCA analysis were used to determine intermediate coronary stenosis.(stenosis between 50% and 70%).Intermediate coronary stenosis were examined by FFR,baseline Pd/Pa,was measured by manual single injection of Nonionic contrast medium 6ml(3ml/s),the contrast-based FFR(cFFR)was measured within 10 s after injection of contrast medium,and the measured value was recorded as group A.Then adenosine triphosphate(140 ? g / kg/min)was infused intravenously.the ATP-based FFR was measured.the measured value was recorded as group B.The correlation and consistency of the two sets of values were analysed.All the data were analyzed by SPSS22.0 statistical software,and a value of P < 0.05 was statistically significant.Results: The normality test was performed on the two groups of data,and the results were obtained in group A(0.8001±0.10954)and group B(0.7779±0.13041).A t-test of two independent samples was performed and no statistical difference between the two groups wasfound(P>0.05).Correlation analysis was performed on the two groups,and there was a significant positive correlation between the two measurements(r=0.83,P<0.001).The Bland-Altman method was used to test the consistency of the two methods.The 95% consistency boundary was calculated as [-0.032,0.078].According to the results of Bland-Altman diagram,more than 95% of the difference is within the boundary,indicating that the two groups of results are in good agreement.With FFR=0.75 as the critical value,?0.75 for drug treatment,<0.75 for percutaneous coronary intervention.The diagnostic value of ROC curve for cFFR was evaluated.the results showed that the area under the curve was 0.989,P<0.001.Youden index was calculated for the sensitivity and specificity of each point of ROC curve,and the corresponding value of the maximum Youden index was taken as the critical value.The critical value of cFFR was 0.825,the sensitivity was 90%,and the specificity was 100%.Conclusion:Contrast-based cFFR has a good correlation and consistency with adenosine triphosphate-based FFR,and cFFR could also be used as a functional indicator to guide intermediate coronary stenosis treatment strategies.