Speckle tracking global strain rate E/E' predicts LV filling pressure more accurately than traditional tissue Doppler E/E'.

BACKGROUND: The ratio of early diastolic transmitral flow velocity (E) to tissue Doppler (TD) mitral annular early diastolic velocity (E/E'(VEL-TD)) has been widely used for the noninvasive assessment of LV diastolic filling pressures. However, it has been reported that E/E'(VEL-TD) is not accurate particularly when being applied to patients with advanced heart failure.

METHODS: Fifty-six ICU patients with decompensated heart failure underwent simultaneous echocardiography and PCWP measurements. Patients with elevated PCWP (n = 41) were compared with patients normal PCWP (n = 15) as well as age-matched healthy controls (n = 32). In the apical 4-chamber view, the ratio of E to speckle tracking (ST) mitral annular velocity (E/E'(VEL-ST)) and early diastolic global LV longitudinal strain rate (E/E'(SR-ST)) were evaluated as new surrogate markers of elevated PCWP.

RESULTS: Correlations with PCWP were observed for speckle tracking derived E/E'(VEL-ST) (r = 0.40,P = 0.002) and E/E'(SR-ST) (r = 0.56, P < 0.001), although the traditional E/E'(VEL-TD) did not show a significant correlation (r = 0.23, P = 0.082). Compared with controls, patients with elevated PCWP had significant increases in all variables. The best cutoff values and diagnostic accuracies for identifying elevated PCWP were E/E'(VEL-TD) >12 (Sensitivity/Specificity/area under the ROC curve: 0.58/0.90/0.78), E/E'(VEL-ST) > 14 (0.60/0.85/0.80), and E/E'(SR-ST) > 93 (0.80/0.88/0.89).

CONCLUSION: Speckle tracking derived E/E'(SR-ST) may be a robust surrogate marker of elevated LV filling pressure. In ICU patients, E/E'(SR-ST) showed better correlation with PCWP and higher diagnostic accuracy than the tissue Doppler approach.