Usefulness of transient elastography for noninvasive and reliable estimation of right-sided filling pressure in heart failure.

Accurate noninvasive assessment of right atrial pressure (RAP) is important for volume management in patients with heart failure (HF). Transient elastography is a noninvasive and reliable method to assess liver stiffness (LS). We investigated the value of LS for evaluation of RAP in patients with HF without structural liver disease. We measured LS using transient elastography (Fibroscan) in 31 patients undergoing right-sided cardiac catheterization (test group). The relation between LS and RAP found in the test group was used to derive the best-fit model to predict RAP. The applicability of the model was then tested in a validation group of 49 additional patients. There was an excellent correlation between LS and RAP in the test group (r = 0.95, p <0.0001; RAP = -5.8 + 6.7 × ln [LS]). Natural log transformation (ln) of LS provided the regression equation to predict RAP. When the equation model derived from the test group was applied to the validation group, predicted RAP correlated excellently with actual RAP (r = 0.90, p <0.0001). The receiver operating characteristic curve analyses in the test group showed that LS favorably compared with echocardiography for detecting RAP >10 mm Hg (area under the curve 0.958 vs 0.800, respectively, p = 0.047). In the validation group, LS with a cut-off value of 10.6 kPa for identifying RAP >10 mm Hg had a higher sensitivity and accuracy (p = 0.046 and p = 0.049, respectively) than echocardiography. In conclusion, LS may offer an accurate noninvasive diagnostic method to assess RAP in patients with HF.