Accuracy of Tissue Doppler Strain in predicting significant Coronary Artery Stenosis.

Background. Strain and strain rate are new techniques in echocardiography that measures the time course of tissue deformation. They are highly sensitive to regional ischemia. The aim of this study is to determine the accuracy of tissue doppler strain in predicting significant coronary artery stenosis.

Methods. This is a cross-sectional study involving 79 consecutive adults with a diagnosis of coronary artery disease who underwent coronary angiography during the same hospital admission. Strain and strain rate analysis along the areas supplied by the respective coronary artery were done. These were correlated with the results of the coronary angiogram.

Results. Among the four myocardial segments supplied by the left circumflex artery,≥2 abnormal segments by strain had a sensitivity of 100%, specificity of 92.9%, positive predictive value of 92.5% and negative predictive value of 100% and ≥2 abnormal segments by strain rate had a sensitivity of 100%, specificity of 83.3%, positive predictive value of 84.1 % and negative predictive value of 100% in predicting at least 70% coronary artery stenosis. Among the three myocardial segments supplied by the right coronary artery,≥2 abnormal segments by strain had a sensitivity of 96.9%, specificity of 97.9%, positive predictive value of 96.9% and negative predictive value of 97.9% and >2 abnormal segments by strain rate had a sensitivity of 100%, specificity of 93.6%, positive predictive value of 91.4% and negative predictive value of 100% in predicting at least 70% coronary artery stenosis.

Conclusion. Determination of the number of abnormal myocardial segments by strain and strain rate analysis of areas supplied by a particular coronary artery had high sensitivity and specificity and good positive and negative predictive value in predicting significant coronary artery stenosis.