Prognostic Implications of Global Longitudinal Strain by Feature-Tracking Cardiac Magnetic Resonance in ST-Elevation Myocardial Infarction

• Published in: Circulation. Cardiovascular imaging Vol. 12; no. 11; p. e009404
• Main Authors: Reindl, Martin, Tiller, Christina, Holzknecht, Magdalena, Lechner, Ivan, Beck, Alexander, Plappert, David, Gorzala, Michelle, Pamminger, Mathias, Mayr, Agnes, Klug, Gert, Bauer, Axel, Metzler, Bernhard, Reinstadler, Sebastian J.
• Format: Journal Article
• Language: English
• Published: United States 01.11.2019
• Subjects: myocardial strain; magnetic resonance imaging; ST-segment elevation myocardial infarction
• ISSN: 1941-9651; 1942-0080; 1942-0080
• DOI: 10.1161/CIRCIMAGING.119.009404

The high accuracy of feature-tracking cardiac magnetic resonance (CMR) imaging qualifies this novel modality as potential gold standard for myocardial strain analyses in ST-elevation myocardial infarction patients; however, the incremental prognostic validity of feature-tracking-CMR over left ventricular ejection fraction (LVEF) and myocardial damage remains unclear. This study therefore aimed to determine the value of myocardial strain measured by feature-tracking-CMR for the prediction of clinical outcome following ST-elevation myocardial infarction. This prospective observational study enrolled 451 revascularized ST-elevation myocardial infarction patients. Comprehensive CMR investigations were performed 3 (interquartile range, 2-4) days after infarction to determine LVEF, global longitudinal strain (GLS), global radial strain, and global circumferential strain as well as myocardial damage. Primary end point was a composite of death, re-infarction, and congestive heart failure (major adverse cardiac events [MACE]). During a follow-up of 24 (interquartile range, 11-48) months, 46 patients (10%) experienced a MACE event. All 3 strain indices were impaired in patients with MACE (all <0.001). However, GLS emerged as the strongest MACE prognosticator among strain parameters (area under the curve, 0.73 [95% CI, 0.69-0.77]) and was significantly better ( =0.005) than LVEF (area under the curve, 0.64 [95% CI, 0.59-0.68]). The association between GLS and MACE remained significant ( <0.001) after adjustment for global radial strain, global circumferential strain, and LVEF as well as for infarct size and microvascular obstruction. The addition of GLS to a risk model comprising LVEF, infarct size, and microvascular obstruction led to a net reclassification improvement (0.35 [95% CI, 0.14-0.55]; <0.001). GLS by feature-tracking-CMR strongly and independently predicted the occurrence of medium-term MACE in contemporary revascularized ST-elevation myocardial infarction patients. Importantly, the prognostic value of GLS was superior and incremental to LVEF and CMR markers of infarct severity.