Acute phase segmental radial strain correlates with recovery and late gadolinium extent in ST-elevation myocardial infarction (STEMI): analysis of the abciximab intracoronary versus intravenously drug application in STEMI substudy

Background: The role of regional strain evaluation in patients with acute reperfused ST-elevation myocardial infarction (STEMI) is not well determined. The objective of this study was the description of regional strain characteristics in the acute and chronic phase of myocardial infarction and its correlation with symptom-to-balloon time and final extent of myocardial scar assessed by cardiac magnetic resonance imaging. Methods: The study cohort has been derived from the randomized controlled Abciximab Intracoronary versus Intravenously Drug Application in STEMI (AIDA STEMI) trial enrolled at the University of Ulm. All patients received comprehensive cardiac magnetic resonance imaging examinations in the acute phase and 6 months later. Results: There was a significant improvement of all global deformation indices over time (global longitudinal strain: -13.1%+/- 5.1% to -15.5%+/- 5.8%, P=0.001; global circumferential strain: -14.4%+/- 3.7% to -16.8%+/- 3.6%, P<0.0001; global radial strain: 28.1%+/- 8.7% to 31.9%+/- 9.2%, P=0.0002). Mean radial strain of ischemic segments significantly improved (16.6%+/- 10.8% to 23.7%+/- 12.8%, P<0.0001), while mean radial strain of remote segments remained unchanged (40.2%+/- 9.4% to 39.4%+/- 9.4%, P=0.570). There was a significant correlation between acute phase radial strain of ischemic segments and either symptom-to-balloon time (P=0.013), as well as extent of late gadolinium enhancement at follow-up (P<0.0001). Using a cut-off of <= 27%, acute phase radial strain predicted infarction of the corresponding segment with high sensitivity and specificity (74.4% and 69.0% respectively, P<0.001). Conclusions: Segmental radial strain in the acute phase of infarction showed a significant correlation to either symptom-to-balloon-time and the extent of late gadolinium enhancement at follow-up, thus potentially serving as early surrogate for left ventricular remodeling and outcome in STEMI.