BACKGROUND: Post-ischemic myocardial diastolic stunning persists for a long time after transient ischemia even after systolic function has recovered. We sought to identify coronary artery stenosis in clinical patients using strain imaging diastolic index (SI-DI) at rest. METHODS: We retrospectively examined 85 patients with suspected coronary artery disease and preserved ejection fraction (EF; >50%) who underwent both echocardiography and coronary angiography. Speckle tracking strains were measured in 3 apical views and parasternal left ventricular (LV) short-axis views at the papillary muscle level. LV segments with inadequate image quality and deficit segments in the movie were excluded by the blinded observer. After strain analysis, LV segments were classified into no stenosis (≤ 50%), mild stenosis (51-75%), and severe stenosis (>75%) groups on the bases of the coronary angiogram. RESULTS: SI-DI decreased significantly in severe stenosis segments (p<0.05, ANOVA), but none of the peak strains showed significant difference. The area under the curve for predicting severe stenosis in radial, longitudinal, and transverse SI-DI was 0.72, 0.74, and 0.80, respectively. A cut-off value of 49 for transverse SI-DI can predict LV segments with severe stenosis with sensitivity of 0.79 and specificity of 0.73. A screening cut-off value of 63 for transverse SI-DI shows sensitivity of 0.95 and specificity of 0.50. CONCLUSION: SI-DI at rest is a novel marker in predicting coronary stenosis even in patients with preserved EF. This index can be used to screen patients with suspected coronary artery disease in routine echocardiography and does not require stress provocation.
BACKGROUND: Post-ischemic myocardial diastolic stunning persists for a long time after transient ischemia even after systolic function has recovered. We sought to identify coronary artery stenosis in clinical patients using strain imaging diastolic index (SI-DI) at rest. METHODS: We retrospectively examined 85 patients with suspected coronary artery disease and preserved ejection fraction (EF; >50%) who underwent both echocardiography and coronary angiography. Speckle tracking strains were measured in 3 apical views and parasternal left ventricular (LV) short-axis views at the papillary muscle level. LV segments with inadequate image quality and deficit segments in the movie were excluded by the blinded observer. After strain analysis, LV segments were classified into no stenosis (≤ 50%), mild stenosis (51-75%), and severe stenosis (>75%) groups on the bases of the coronary angiogram. RESULTS:SI-DI decreased significantly in severe stenosis segments (p<0.05, ANOVA), but none of the peak strains showed significant difference. The area under the curve for predicting severe stenosis in radial, longitudinal, and transverse SI-DI was 0.72, 0.74, and 0.80, respectively. A cut-off value of 49 for transverse SI-DI can predict LV segments with severe stenosis with sensitivity of 0.79 and specificity of 0.73. A screening cut-off value of 63 for transverse SI-DI shows sensitivity of 0.95 and specificity of 0.50. CONCLUSION:SI-DI at rest is a novel marker in predicting coronary stenosis even in patients with preserved EF. This index can be used to screen patients with suspected coronary artery disease in routine echocardiography and does not require stress provocation.