Longitudinal strain is a marker of microvascular obstruction and infarct size in patients with acute ST-segment elevation myocardial infarction.
OBJECTIVE
We assessed the value of speckle tracking imaging performed early after a first ST-segment elevation myocardial infarction (STEMI) in order to predict infarct size and functional recovery at 3-month follow-up.


METHODS
44 patients with STEMI who underwent revascularization within 12 h of symptom onset were prospectively enrolled. Echocardiography was performed 3.9 ± 1.2 days after myocardial reperfusion, assessing circumferential (CGS), radial (RGS), and longitudinal global (GLS) strains. Late gadolinium-enhanced cardiac magnetic imaging (CMR), for assessing cardiac function, infarct size, and microvascular obstruction (MVO), was conducted 5.6 ± 2.5 days and 99.4 ± 4.6 days after myocardial reperfusion.


RESULTS
GLS was evaluable in 97% of the patients, while CGS and RGS could be assessed in 85%. Infarct size significantly correlated with GLS (R = 0.601, p<0.001), RGS (R = -0.405, p = 0.010), CGS (R = 0.526, p = 0.001), ejection fraction (R = -0.699, p<0.001), wall motion score index (WMSI) (R = 0.539, p = 0.001), and left atrial volume (R = 0.510, p<0.001). Baseline ejection fraction and GLS were independent predictors of 3-month infarct size. MVO mass significantly correlated with GLS (R = 0.376, p = 0.010), WMSI (R = 0.387, p = 0.011), and ejection fraction (R = -0.389, p = 0.011). In multivariate analysis, GLS was the only independent predictor of MVO mass (p = 0.015). Longitudinal strain >-6.0% within the infarcted area exhibited 96% specificity and 61% sensitivity for predicting the persistence of akinesia (≥ 3 segments) at 3-month follow-up.


CONCLUSIONS
Speckle-tracking strain imaging performed early after a STEMI is easy-to-use as a marker for persistent akinetic territories at 3 months. In addition, GLS correlated significantly with MVO and final infarct size, both parameters being relevant post-MI prognostic factors, usually obtained via CMR.
L'UNAM Université, Angers, France ; Université Angers, UPRES EA3860, Laboratoire Cardioprotection, Remodelage et Thrombose, CHU Angers, Service de Cardiologie, Angers, France.
Loïc
L
Bière
Service de Cardiologie et CIC-IT 804, CHU de Rennes & Laboratoire Traitement du Signal et de l'Image, INSERM U1099, Rennes, France.
Erwan
E
Donal
L'UNAM Université, Angers, France ; Université Angers, UPRES EA3860, Laboratoire Cardioprotection, Remodelage et Thrombose, CHU Angers, Service de Cardiologie, Angers, France.
Gwenola
G
Terrien
Service de Cardiologie et CIC-IT 804, CHU de Rennes & Laboratoire Traitement du Signal et de l'Image, INSERM U1099, Rennes, France.
Gaëlle
G
Kervio
L'UNAM Université, Angers, France ; Université Angers, UPRES EA3860, Laboratoire Cardioprotection, Remodelage et Thrombose, CHU Angers, Service de Radiologie, Angers, France.
Serge
S
Willoteaux
L'UNAM Université, Angers, France ; Université Angers, UPRES EA3860, Laboratoire Cardioprotection, Remodelage et Thrombose, CHU Angers, Service de Cardiologie, Angers, France.
Alain
A
Furber
L'UNAM Université, Angers, France ; Université Angers, UPRES EA3860, Laboratoire Cardioprotection, Remodelage et Thrombose, CHU Angers, Service de Cardiologie, Angers, France.
Fabrice
F
Prunier
D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D012372:ROC Curve; D015203:Reproducibility of Results