Direct comparison of coronary microvascular obstruction evaluation using CMR feature tracking and layer-specific speckle tracking echocardiography in STEMI patients

PURPOSE: Layer-specific speckle tissue echocardiography (LS-STE) is a unique technique used to assess coronary microvascular obstruction (CMVO) that may offer more information on the myocardial anatomy of patients with ST-elevation myocardial infarction (STEMI). Cardiovascular magnetic resonance feature tracking (CMR-FT) has also been gaining popularity as a way to evaluate CMVO. The aim of the present study was to directly compare CMVO assessment in STEMI patients using CMR-FT and LS-STE. PATIENTS AND METHODS: A total of 105 STEMI patients with LS-STE, CMR-FT, and primary percutaneous coronary intervention (PPCI) were included in the study. Longitudinal peak systolic strain (LS), circumferential peak systolic strain (CS), and radial peak systolic strain (RS) were each used to evaluate CMVO using CMR-FT and LS-STE. RESULTS: Correlation coefficients were 0.56, 0.53, and 0.55 for CMR-FT CS vs. endocardial CS, midcardial CS, and epicardial CS comparisons, respectively, and 0.87, 0.51, and 0.32 for CMR-FT LS vs. endocardial LS, midcardial LS, and epicardial LS comparisons, respectively. Bland-Altman analysis revealed strong inter-modality agreement and little bias in endocardial LS, while the absolute of limited of agreement (LOA) value was 2.28 ± 4.48. The absolutes LOA values were 1.26 ± 11.16, -0.02 ± 12.21, and - 1.3 ± 10.27 for endocardial, midcardial, and epicardial respectively. Intraclass correlation coefficient value of 0.87 showed good reliability in endocardial LS, and moderate reliability with values of 0.71, 0.70, and 0.64 in endocardial, midcardial, and epicardial CS, respectively (all p < 0.001). CONCLUSIONS: CMR-FT is a viable technique for CMVO evaluation in STEMI patients. Endocardial LS showed good reliability for CMR-FT. STEMI patients can undergo LS-STE to assess the CMVO before PPCI.