The Value Of Myocardial Contrast Echocardiography In The Diagnosis Of Coronary Microcirculation Dysfunction In Non-obstructive Coronary Ischemic Disease

Objective:To explore the diagnostic value of myocardial contrast echocardiography（MCE）for coronary microcirculation dysfunction（CMCD）in non-obstructive coronary artery ischemic disease.Methods:From January 2021 to June 2022,21 patients（n=21）with clinically diagnosed non-obstructive coronary artery ischemic disease were collected from the First Affiliated Hospital of Xinjiang Medical University due to chest pain.All subjects were confirmed by coronary angiography or coronary CTA to have coronary artery stenosis≤50%.All subjects underwent MCE and ¹⁸F-FDG PET/CT myocardial metabolic imaging.Taking ¹⁸F-FDG PET/CT myocardial metabolic imaging results as the"gold standard",all myocardial segments were divided into normal control group and CMCD group.The following myocardial perfusion parameters were measured by MCE:ascending slopeβ,Time to peak TTP,etc.To evaluate the diagnostic efficacy of MCE in non-obstructive coronary ischemia CMCD by calculating the area under the ROC curve of myocardial perfusion parameters.Results:A total of 21 subjects were collected and a total of 357 segments were available for analysis,of which 17 segments could not be analyzed due to poor image quality,and the remaining 340 segments were available for analysis,including 122 segments in the CMCD group and 218 segments in the normal control group.Through statistical analysis of MCE perfusion parameters of the two groups,it is concluded that:（1）In CMCD group,myocardial perfusion parametersβand A*βdecreased in the basal,middle and apical segments of the LAD and the RCA,and in the basal and middle segments of the LCX;the myocardial perfusion parameter AUC of CMCD group decreased in the apical segment of the LAD,the basal segment of the LCX,the middle segment and apical segment of the RCA;in CMCD group,A decreased in the basal and middle segments of the RCA,these differences were statistically significant（P<0.05）.（2）According to the analysis of ROC curve,the AUC ofβin the middle segment is the largest,0.861,and its sensitivity in the apical segment is the highest,78.95%,and its specificity in the middle segment is the best,96.51%.（3）The results of¹⁸F-FDG PET myocardial metabolic imaging showed that the microcirculation damage of myocardial segments supplied by LAD and RCA is more severe than that of myocardial segments supplied by LCX;the damage of microcirculation in apical segment is more serious than that in basal and middle segments.（4）The intra-group correlation coefficient（ICC）showed that all parameters had good intra-observer and inter-observer consistency.Conclusion:MCE can evaluate the myocardial perfusion of non-obstructive coronary artery CMCD from multiple parameters,βis better than TTP,A,AUC and A*βin detecting CMCD segments.Multiple myocardial perfusion parameters can improve the diagnostic efficiency of MCE for CMCD.