The VIRTUE Index: A Novel Echocardiographic Marker Integrating Right–Left Ventricular Hemodynamics in Acute Heart Failure

Background/Objectives: Acute heart failure (AHF) is a heterogeneous syndrome with phenotype-dependent prognosis. NT-proBNP is the reference biomarker, but standard echocardiographic measures (TAPSE, RV–RA gradient, LVOT VTI) offer only partial prognostic insight. The Virtue Index, defined as (RV–RA gradient)/(TAPSE × LVOT VTI), was introduced to integrate right–left ventricular interaction. This study evaluated its clinical and prognostic performance in AHF and its behavior across ejection-fraction phenotypes. Methods: We retrospectively analyzed 222 patients with AHF; complete data for Virtue calculation were available in 168 (99 HFrEF, 69 HFpEF) patients. HFmrEF patients were excluded from subgroup prognostic analyses. Correlation with NT-proBNP was assessed using Spearman testing with bootstrap intervals, and in-hospital mortality prediction was evaluated using ROC analysis with DeLong comparisons. Results: In HFpEF, the Virtue Index correlated moderately with NT-proBNP (ρ = 0.38, p = 0.002) and showed fair prognostic discrimination (AUC 0.704), similar to the RV–RA gradient (0.724) and higher than TAPSE or LVOT VTI. In HFrEF, correlation was weak (ρ = 0.19, p = 0.06) and predictive accuracy was modest (AUC 0.584), while LVOT VTI performed best (AUC 0.700). NT-proBNP outperformed all echocardiographic parameters in both groups. Conclusions: The Virtue Index reflects integrated hemodynamics and shows phenotype-dependent prognostic value in AHF, being more informative in HFpEF than in HFrEF. Although NT-proBNP remained superior, Virtue may complement biomarker-based risk assessment by offering a rapid, bedside estimate of short-term mortality risk.