Myocardial Viability Assessment by Dobutamine Echocardiography using Speckle-Tracking: Comparison with cardiac MRI delay enhancement

Abstract

Background: The use of myocardial strain imaging during dobutamine echocardiography may facilitate the prediction of myocardial viability. speckletracking echocardiography (STE) are used for myocardial strain measurement, it needs validation for prediction of viability . Aim of the study: To determine the accuracy of STE-based measurements of myocardial strain for the detection of myocardial viability before revascularization using MRI delayed enhancement imaging as agold standard. Methods: The study included 20 patients (14 males , 6 females), mean age (58±9.4 years) with ischemic heart disease and left ventricular systolic dysfunction; who were undergoing dobutamine stress echocardiography and MRI for assessment of myocardial viability ,The patients were divided into two groups according to the result of MRI delayed enhancement into viable and non-viable myocardial segments for possibility of myocardial revascularization. Speckle tracking technique (STE )were used to measure longitudinal peak systolic strain at rest and at low-dose dobutamine (LDD). Results: according to MRI delayed enhancement result, non-viable myocardial segments had significantly lower longitudinal peak systolic strain at LDD (-4.7) compared with rest (-6.4) by STE and viable myocardial segments had significantly higher longitudinal peak systolic strain at LDD (-15.8) compared with rest (-13.5) by STE .The performance of measurements obtained by Echo Speckle tracking at rest and after LDD in diagnosing a viable cardiac segment was tested by ROC methodIn addition, the LDD measurements were associated with an observed higher validity in predicting a viable cardiac segment as reflected by the higher area under ROC curve (0.873 compared to 0.78 observed with at rest measurements). Conclusion: peak longitudinal strain measurements with STE at LDD echocardiography can predict myocardial viability