Discordant severity grading in right ventricular dysfunction: prognostic implications of conventional parameters versus 3D echocardiography-derived ejection fraction

Introduction The 2025 American Society of Echocardiography guidelines on the right heart introduce severity grading for right ventricular (RV) dysfunction across individual functional parameters, including tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), free-wall longitudinal strain (FWLS), and 3D echocardiography-derived RV ejection fraction (RVEF). However, isolated assessment using individual parameters may result in inconsistent grading, and the relationship between severity grades and adverse clinical outcomes remains to be validated. Purpose Accordingly, we aimed to investigate the prognostic value and discordance among severity grades of RV dysfunction as assessed by TAPSE, FAC, FWLS, and RVEF. Methods We analyzed 2D and 3D echocardiographic data from two centers, including 750 patients followed for the composite primary endpoint of all-cause mortality and heart failure hospitalization. The severity of RV dysfunction was classified using the guideline-recommended cutoff values for TAPSE, FAC, and FWLS, and these classifications were compared with the severity grades based on RVEF. Results Over a median follow-up of 3.2 years, 183 patients (24%) met the primary endpoint. Kaplan-Meier analysis showed that worsening RV function categories by RVEF was associated with progressively increased risk of adverse outcomes, significant between normal vs. mild (HR: 2.628 [95% CI: 1.571 – 4.399], log-rank p<0.001), and mild vs. moderate groups (HR: 1.833 [95% CI: 1.106 – 3.039], p=0.019), but not between moderate vs. severe (Figure 1A). TAPSE-based classification showed a nearly twofold higher risk across all dysfunction groups compared to normal, but without significant differences between the dysfunction groups (Figure 1B). FAC identified a significant risk difference between adjacent severity categories only for the mild vs. moderate group (HR: 2.054 [95% CI: 1.279 – 3.297], p<0.001) (Figure 2A). FWLS showed higher risk in normal vs. mild (HR: 2.241 [95% CI: 1.412 – 3.557], p<0.001) and mild vs. moderate groups (HR: 1.668 [95% CI: 0.957 – 2.908], p=0.045) (Figure 2B). Concordance between TAPSE and RVEF-based classification was low, with agreement rates of 17%, 14%, and 18% for mild, moderate, and severe dysfunction, respectively. FAC showed similarly low agreement with RVEF, particularly for mild (16%) and moderate (21%) dysfunction, improving only for severe dysfunction (52%). FWLS demonstrated the highest, though modest, concordance with RVEF — 27% for mild, 30% for moderate, and 83% for severe dysfunction. Conclusion Significant discordance was observed between conventional echocardiographic parameters and RVEF in grading RV systolic dysfunction. None of the individual RV functional parameters provided consistent risk stratification, highlighting their limited prognostic utility when used in isolation. These findings emphasize the need for a multiparametric approach to RV function assessment.