Increase of Modified Retrograde to Antegrade Flow Ratio on Doppler Ultrasounds of the Hepatic Vein Indicating Tricuspid Regurgitation During Follow-up of Liver Transplantation: Correlation With Echocardiographic Results

The purpose of this study was to explore the best parameter of hepatic vein (HV) Doppler ultrasounds (DUS) that correlated with echocardiographic findings of and particularly the optimal cutoff value for tricuspid regurgitation (TR) following liver transplantation (LT). Thirty-six patients underwent echocardiography and DUS after LT from January 2006 to July 2007. Echocardiographic records were searched for TR grade and peak velocity of TR flow. The HV DUS parameters included peak velocity of retrograde flow (R), peak velocity of antegrade flow (A), the difference between R and A (R-A), the ratio of R to A (R/A ratio), and a modified R/A ratio, namely, the product of the R/A ratio and the R/A duration ratio. Correlation tests and receiver-operator characteristic analyses explored their interrelations and to obtained cutoff values to diagnose moderate and severe TR. TR grade best correlated with the modified R/A ratio (rho = 0.585), followed by the R/A ratio (rho = 0.503) and R (rho = 0.455). The modified R/A ratio was the most accurate parameter for the diagnosis of moderate and severe TR (Az = 0.825 and 0.895, respectively); its cutoff value was ≥0.11 for moderate TR (sensitivity and specificity both 77.78%) and 0.13 for severe TR (sensitivity, 100%; specificity, 81.2%). The modified R/A ratio best correlated with echocardiographic results of TR, although the strength of correlation was only moderate. Additionally, the modified R/A ratio was an accurate DUS parameter to diagnose moderate and severe TR among patients following LT.