Background: Interpretation of dobutamine stress echocardiogram (DSE) is often subjective and requires expert training. The purposes of this study was to determine optimal cutoff values for longitudinal, circumferential, and radial strains at peak DSE for detection of significant stenoses on coronary angiography and to investigate incremental value of combining strain measurements to wall motion analysis.
Methods: In this multicenter study, 102 patients underwent concomitant DSE and coronary angiography. Optimal cutoff values for mean global longitudinal (-20%), global circumferential (-26%), and mean radial (50%) strains at peak stress for detection of significant stenoses on coronary angiography were determined in a derivation group (n = 62) and tested in a prospectively recruited validation group (n = 40).
Results: Respective sensitivities for longitudinal, circumferential, radial strains, and expert wall motion score index (WMSI) were 84.2%, 73.9%, 78.3%, and 76%; respective specificities were 87.5%, 78.6%, 57.1%, and 92.9%; and respective accuracies were 85.2%, 75.7%, 70.3%, and 82.1%. Longitudinal strain analysis had comparable accuracy to WMSI (P = .70). However, combination longitudinal strain and WMSI had the highest sensitivity, specificity, and accuracy (100%, 87.5%, and 96.3% respectively), and its diagnostic accuracy was incremental to either longitudinal strain (P = .034) or WMSI alone (P = .008).
Conclusion: Longitudinal strain analysis had higher diagnostic accuracy than circumferential and radial strains and was comparable to WMSI for detection of significant coronary artery disease. However, combination longitudinal strain and WMSI resulted in significant incremental increase in diagnostic accuracy.