ABSTRACT
AIM: The aim of the present study was to explore the accuracy of the dobutamine-induced percent change of myocardial deformation indices to detect viability following myocardial infarction. METHODS: We enrolled 60 consecutive patients presenting for myocardial viability assessment at least 4 weeks following ST-segment-elevation myocardial infarction. Strain (S) and strain rate (SR) were individually measured for all myocardial segments, both at rest and during low-dose dobutamine stress echocardiography. The percent change of S and SR from baseline to dobutamine-induced values (at a dose of 20 µg/kg/min) was calculated individually for each segment. Patients underwent myocardial viability assessment with resting 99mTc-sestamibi scintigraphy. Based on the results of scintigraphy, the percent change of S and SR was compared between viable and non-viable segments. RESULTS: For all segments, the percent change of both S and SR was significantly higher in viable as compared with non-viable segments (P<0.05 for all). Receiver-operating characteristics curve analysis identified the optimal cut-off value for the percent change of both S and SR that best discriminates viable from non-viable segments in the range of 20-25% with a sensitivity range from 95% to 100%, and a specificity range from 85% to 100%. CONCLUSION: In patients undergoing viability assessment following ST segment elevation myocardial infarction, the percent change of both S and SR (from baseline to dobutamine-induced values) was significantly higher in viable versus non-viable segments. A cut-off value of 20-25% of the percent change for both S and SR reliably identified viable from non-viable segments with a high sensitivity and specificity for both.
