Underlying Coronary Microvascular Disease May Lead to Underestimation of Global Longitudinal Strain Differences.

To the Editor:

We read with interest the original article by Srinivasan G, et al. [1]. In the study, the methodology stated that “Participants with normal coronaries and non-obstructive disease were taken as the control group.” The speckle-tracking Echocardiography-derived Global Longitudinal Strain (GLS) is a sensitive modality for obtaining the GLS. The participants presenting with chest pain with normal coronaries on angiography and non-obstructive disease accepted as control may have microvascular coronary artery disease affecting the control GLS values, leading to underestimation of the difference between the disease and control group. Studies have shown that patients with coronary microvascular disease are known to have a significant lowering of coronary reserves, thus affecting patterns of GLS [2,3]. Thereby, this should be taken into consideration when interpreting the results of this study.