Background: Recently, two new indexes based on the ratio of transmitral early diastolic velocity (E) to tissue Doppler imaging (TDI), and early diastolic velocity of mitral annulus (E’) and E to propagation velocity (Vp) have been proposed to predict left ventricular (LV) filling pressures. However, little is known about the comparative value of these two indexes.
Methods: We studied 71 consecutive patients referred for coronary angiography (mean age ± SD, 65 + 11 years; 21 patients with LV ejection fraction [EF] < 50%). Complete Doppler echocardiographic examination including TDI and Vp measurements and direct measurement of LV end-diastolic pressure (LVEDP) were performed simultaneously in the catheterization laboratory. LV filling pressures were considered elevated when LVEDP was ≥ 15 mm Hg.
Results: The correlation coefficients between E/E’ and E/Vp and LVEDP were 0.68 (p = 0.01) and 0.54 (p = 0.01), respectively, in the overall population. The correlations were better in patients with low LV EF (< 50%) [0.8 (p = 0.01) and 0.77(p = 0.01)] and poor in patients with normal LV EF (0.57 [p = 0.05] and 0.41 [not significant]), respectively. Moreover, Vp measurements had higher interobserver variability compared to E’ (14% vs 7%). The cutoff values for both indexes giving the best sensitivity and specificity in identifying LVEDP ≥ 15 mm Hg were 9 for (E/E’) and 2 for (E/Vp)
Conclusion: Both E/E’ and E/Vp can be used for the evaluation of LV filling pressures. However, the sensitivity of these indexes, especially E/Vp, is hampered by EF. E/E’ has a lower variability than Vp and should be preferred for estimation of filling pressures especially in patients with EF > 50%.