Predictive value of global and regional speckle tracking analysis in patients enrolled in the ECHO-FIRE study

Background left ventricular (LV) global longitudinal strain (GLS) measures the longitudinal deformation of subendocardial fibers, which are sensitive to myocardial ischemia. Regional strain reduction may indicate coronary stenosis or predict ventricular remodelling after revascularization. Purpose the aim of the present study was to asses the prognostic value of speckle-tracking analysis in elderly patients with ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) with multivessel disease treated by percutaneous coronary intervention (PCI) at 1-year follow-up. Methods this sub-analysis derives from the "Functional versus Culprit-only Revascularization in Elderly Patients with Myocardial Infarction and Multivessel Disease" (FIRE) trial, a multicenter, randomized study enrolling patients >75 years with acute myocardial infarction and multivessel disease undergoing PCI of the culprit lesion, who were randomized to receive either physiology-guided complete revascularization of nonculprit lesions or no further revascularization. We included only patients with a transthoracic echocardiogram performed at our department after the index procedure in STEMI and before revascularization in NSTEMI patients. Speckle-tracking echocardiography assessed layer specific GLS— epicardial, mid-myocardial, and endocardial—and segmental strain. Regional strain was calculated based on coronary artery territories. The primary endpoint was a composite of all-cause death, myocardial infarction, stroke and coronary revascularization within 1 year. Univariable and multivariable Cox regressions were performed; p < 0.05 was significant. Results a total of 174 patients were enrolled, the median age was 80 years (IQR 75.7–85.3). Among them, 106 were admitted for NSTEMI; 42 reached the primary endpoint. STEMI patients showed lower regional GLS values in left anterior descending artery (LAD) (-11.4 ± 6.8, p < 0.009) and right coronary artery (RCA) (-11.1 ± 4.2, p < 0.005) territories compared to NSTEMI patients. Patients with events (EP+) were older (81.7 ± 5.5, p<0.04), had lower ejection fraction values (44.2 ± 11.9 vs. 51.1 ± 12.3, p < 0.001), and worse speckle-tracking parameters compared to those without events (EP-). Reduced global, layer-specific, and regional GLS predicted events in univariable analysis (HR 1.1, 95% CI 1–1.2, p < 0.01), but only age remained significant in multivariable analysis (HR 1.1, 95% CI 1–1.6, p < 0.01). Reduced GLS in LAD and RCA territories predicted events at univariable analysis in both STEMI and NSTEMI patients, but not at multivariable. Conclusions in patients with STEMI, regional GLS appear to be more severely impaired compared to NSTEMI, and lower GLS values are associated with worse clinical outcomes. However, GLS cannot be considered an independent predictor of outcome in elderly patients with multivessel acute myocardial infarction.