Longitudinal Strain Versus Exercise Treadmill Testing in Chronic Stable Angina

Background: Longitudinal strain analysis has been shown to be useful in patients with acute coronary syndromes and in stress echocardiography. The objective of this study is to identify the incremental diagnostic value of longitudinal strain analysis at rest, when added to routine treadmill testing (TMT), in identifying the presence of coronary artery disease in patients presenting with chronic stable angina (CSA). Methodology: We conducted a prospective study in which adult patients presenting with CSA and normal systolic function were enrolled. All patients were examined by 2-D echocardiography, longitudinal strain analysis, TMT, and either conventional coronary angiography and/ or coronary computed tomography angiography. Results: We enrolled a total of 150 subjects (54±7.8 years, 63% male). The sensitivity and specificity of TMT was 60.2% and 65.5% respectively. In comparison, global longitudinal strain (GLS) alone had better sensitivity (72.7%) and specificity (74.2%). Post-systolic shortening (PSS) had similar sensitivity for early detection of significant CAD. The combination of TMT and GLS provided the best overall diagnostic accuracy with a sensitivity of 85.4% and specificity of 87.5%, respectively. The optimal cut off for GLS for identification of coronary artery disease was-17.75%. Conclusions: In patients presenting with chronic stable angina and normal systolic function, global longitudinal strain and post systolic shortening assessed at rest have excellent diagnostic accuracy for coronary artery disease. Longitudinal strain analysis is superior to conventional TMT and adds to its diagnostic performance.