Abstract
BACKGROUND: To determine the accuracy of global longitudinal strain and territorial longitudinal strain in determining myocardial viability in comparison to single-photon emission computed tomography in out of window period anterior wall myocardial infarction patients. METHODS: This was a single-center, prospective study carried out in a tertiary care center in northern India. All patients presenting with anterior wall myocardial infarction-out of window period without ongoing chest pain and akinetic left-anterior descending territory on echocardiography were recruited. All patients underwent strain echocardiography and the determination of both global longitudinal strain and territorial longitudinal strain within 12-48 hours of anterior wall myocardial infarction. In addition, all underwent single-photon emission computed tomography to determine the viability status of the anterior myocardium. RESULTS: Fifty-one patients of anterior wall myocardial infarction-out of window period were enrolled and underwent strain imaging with speckle tracking and single-photon emission computed tomography for viability determination. Gobal longitudinal strain and territorial longitudinal strain were significantly reduced in patients with nonviable myocardium (P < .001). On receiver-operating curves, a gobal longitudinal strain of <10.45% had a sensitivity of 77.8% and specificity of 93.9% (AUC=0.889) in predicting nonviability on single-photon emission computed tomography. Similarly, a territorial longitudinal strain of <7.60% had a sensitivity of 77.8% and specificity of 84.8% (AUC=0.825) in predicting nonviability. CONCLUSIONS: Treatment strategies in patients presenting with anterior wall myocardial infarction, outside the window period is largely guided by the hemodynamic status and influenced by the viability status of the myocardium. Strain echocardiography using speckle tracking provides gobal longitudinal strain and territorial longitudinal strain, both of which have good sensitivity and specificity in predicting viability and can be performed safely and quickly in high-risk group of patients.