Prediction of infarct size and adverse cardiac outcomes by tissue tracking-cardiac magnetic resonance imaging in ST-segment elevation myocardial infarction.

OBJECTIVES: We investigated whether quantification of global left ventricular (LV) strain by tissue tracking-CMR (TT-CMR) can estimate the infarct size and clinical outcomes in patients with acute myocardial infarction (MI).

METHODS: We retrospectively registered 247 consecutive patients (58 ± 12 years; male, 81%) who underwent 1.5-T CMR within 1 month after ST-segment elevation MI (median, 4 days; interquartile range, 3-6 days), and 20 age- and sex-matched controls (58 ± 11 years; male, 80%). TT-CMR analysis was applied to cine-images to measure global LV radial, circumferential and longitudinal peak strains (GRS, GCS and GLS, respectively). Adverse cardiac events were defined as cardiac death and hospitalization for heart failure.

RESULTS: During the follow-up (median, 7.8 years), 20 patients (8.1%) experienced adverse events. LV myocardial deformation was significantly decreased in MI patients compared to controls and closely related to the infarct size. The GRS, GCS and GLS were all significant predictors of adverse cardiac events. In particular, a GLS > -14.1% was independently associated with a > 5-fold increased risk for adverse events, even after adjustment for the LV ejection fraction and infarct size.

CONCLUSIONS: TT-CMR-derived LV strain is significantly related to the infarct size and adverse events. GLS measurement provides strong prognostic information in MI patients.

KEY POINTS: • TT-CMR provides reliable quantification of LV strain in MI patients. • TT-CMR allows prediction of the infarct size and adverse events. • In particular, GLS by TT-CMR had independent prognostic value in MI patients.