Clinical Evaluation Of Cardiac Magnetic Resonance Tissue Tracking Technology For Coronary Heart Disease Patients With Myocardial Infarction

Objective: Echocardiography and cardiac magnetic resonance can measure myocardial motion and deformation noninvasively.The purpose of this study was to investigate the clinical value of cardiac magnetic resonance tissue tracking technology(CMR-TT)in assessing left ventricular function in patients with coronary artery disease(CAD)and in correctly diagnosing myocardial infarction.Methods: Twenty three patients with coronary artery disease and 16 healthy volunteers underwent 3.0 T CMR,including CMR cine and late gadolinium enhancement.We use CVI42 software to measure heart function.The cardiac function was measured with CVI42 software and the global or egmental strain of left ventricle was analyzed using tissue tracking technology to obtain myocardial 3D strain parameter values in all directions.The mean value of the above parameters were compared among groups,ICC analysis,Pearson correlation analysis,Logistic regression model and receiver operating characteristic analysis(ROC analysis).Results: The overall left ventricular radial strain(ICC=0.944),circumferential strain(ICC=0.988)and longitudinal strain(ICC= 0.987)showed good repeatability.The radial strain,circumferential strain and longitudinal strain in the left ventricle in the CAD group were significantly lower than those in the healthy group [(30.35 ± 17.26)% vs(45.46 ± 8.9%,(-13.92 ± 5.77)% vs(-19.34 ± 2.3%),(-11.3 ± 4.75)% vs(-16.54 ± 2.4)%,P<0.01].Left ventricular ejection fraction was strongly correlated with radial strain(r=0.774,P<0.001)and strongly correlated with circumferential strain(r=0.778,P<0.001)and strongly correlated with longitudinal strain(r=0.802,P<0.001).The peak values of radial strain,circumferential strain and longitudinal strain of LGE-positive myocardial segments in coronary heart disease group were lower than those in LGE-negative myocardial segments [(9.95)% vs(41.42%,(-7.67)% vs(-17.2%(-6.68)% vs(-13.83)%,P < 0.01].Myocardial radial strain(AUC=0.914)and circumferential strain(AUC=0.911)have high diagnostic value in the diagnosis of myocardial infarction.When the cut-off value of myocardial radial strain was 16.83%,the diagnostic accuracy was high(Youden index=0.7399).When the circumferential strain cutoff is-11.44%,the diagnostic accuracy is high(Youden index=0.7511).Longitudinal strain With a cut-off value of-9.41%,diagnostic accuracy is low(Youden index =0.5552).When we use the radial strain and circumferential strain combined diagnosis of myocardial infarction of coronary heart disease,AUC,sensitivity and specificity than independent diagnosis of each index increased.Conclusions: Cardiac magnetic resonance tissue tracking has good feasibility and repeatability in clinical application.Radial strain,circumferential strain and longitudinal strain have a strong correlation with left ventricular ejection fraction of coronary heart disease.Radial strain and circumferential strain in the diagnosis of myocardial infarction in coronary heart disease higher diagnostic value.When we use these two indicators combined diagnosis can improve diagnostic performance.This suggests that CMR-TT strain analysis has potential clinical value in identifying myocardial infarction segments without coronary contrast.