Cardiac Magnetic Resonance Feature Tracking Global and Segmental Strain in Acute and Chronic ST-elevation Myocardial Infarction

Objectives: Strain is an important imaging parameter to determine myocardial deformation. This study sought to 1) assess changes in left ventricular strain and ejection fraction (LVEF) from acute to chronic ST-elevation myocardial infarction (STEMI) and 2) analyze strain as a predictor of late gadolinium enhancement (LGE). Methods: 32 patients with STEMI and 18 controls prospectively underwent cardiac magnetic resonance imaging. Patients were scanned 8±5 days and six months after infarction (±1.4 months). Feature tracking was performed and LVEF was calculated. LGE was determined visually and quantitatively on short-axis images and myocardial segments were grouped according to the LGE pattern (negative, non-transmural and transmural). Results: Global strain was impaired in patients compared to controls, but improved within six months after STEMI (longitudinal strain from -14±4 to -16±4%, p<0.001; radial strain from 38±11 to 42±13%, p=0.006; circumferential strain from -15±4 to -16±4%, p=0.023). Regional strain persisted impaired in LGE-positive segments. LVEF was preserved (51±12 and 53±10%, p=0.206). Circumferential strain could best distinguish between LGE-negative and -positive segments (AUC 0.73- 0.77). Conclusion: Strain improves within six months after STEMI, but remains impaired in LGE-positive segments. Strain may serve as an imaging biomarker to analyze myocardial viability. Especially circumferential strain could predict LGE.