Background: Late diastole is related with left ventricular stiffness. Our hypothesis was that the combination of both early and late diastolic parameters may predict LV end-diastolic pressure (LVEDP) more accurately than the previous index, E/e' ratio which uses only early diastolic parameters. Methods: LVEDP and coronary angiogram (CAG) were obtained within 2-h after standard echocardiography with tissue Doppler imaging. Medial and lateral mitral annular tissue velocities were obtained and mean value was used for analysis. Patients with normal CAG were excluded. Results: A total of 50 patients (30 men; mean ages, 63.2 짹 9.8 years) were enrolled. LV ejection fraction was 68 짹 11 %. E/e��� ratio showed positive correlation with LVEDP (r = 0.406, p = 0.003).The ratio of E velocity to late diastolic mitral annular tissue velocity (E/a') showed stronger positive correlation with LVEDP (r = 0.502, p < 0.001) compared to E/e��� ratio (Figure 1). The ratio of A velocity to a��� velocity (A/a���) did not show significant correlation with LVEDP (r = 0.233, p = 0.104). In ROC curve analysis, an E/a��� ratio > 8 was the optimal cut-off value for predicting LVEDP > 15mmHg with a sensitivity of 77% and specificity of 76% (Figure 2). Conclusion: E/a' ratio which uses both early and late diastolic Doppler parameters showed better correlation with LVEDP compared to E/e��� ratio in patients with coronary artery disease. E/a' ratio may be used as an alternative index for the assessment of diastolic function.