analyzing the application of myocardial blood flow index in the diagnosis of in-stent stenosis

Background: in-stent restenosis (isr) usually develops from stent neointimal hyperplasia (snh), which will seriously weaken the effect of treatment. in this study, both snh and isr were classified as in-stent stenosis (iss), and a non-invasive parameter – myocardial blood flow index (mbfi) was used to analyze its value in the diagnosis of stent abnormalities.objectives: analyzing the application of mbfi in the diagnosis of iss.patients and methods: clinical follow-up data for 572 patients with drug-eluting stent (des) was collected continuously. ninety cases were screened with the protocol of coronary computed tomography angiography (ccta) and invasive coronary angiography (ica) for the unrelieved symptoms. in-stent abnormalities includedsnh(iss< 50%) and isr (iss 50%). theroccurve was analyzed using the optimal cutoff value of mbfi to evaluate the in-stent abnormalities. t-test of independent samples was used for the comparison data with normal distribution, and chi-square test was used for comparison of nominal variables. p < 0.05 was considered statistically significant.[results]frequency of iss was not statistically different between genders (χ^2 = 0.105) (p = 0.7463). the optimal cutoff value was 0.082 with the area under the curve (auc) of 0.829 (p<0.001). the sensitivity, specificity, positive predictive value, and negative predictive value were 91.4%, 89.1%, 84.2%, and 94.2%, respectively, and the accuracy was 90.0%. among 39 cases with mbfi ≤ 0.082, 34 (37.8%, 34/90) were with iss, including 18 (20%, 18/90) of snh, and 16 (17.8%, 16/90) of isr. in the 39 cases with mbfi ≤ 0.082, there were eight (20.5%, 8/39) presented new lesions, and seven (17.9%, 7/39) presented severe lesions.[conclusion]mbfi could be used for evaluating iss, and more attention should be paid to the new accompanying lesions for the high risk of severe lesions.