Prognostic impact of right ventricular functional-afterload mismatch at 6 months after heart transplantation
L Martini, L Carli, F M Righini, S Bernazzali, A Selimi, M Maccherini, S Valente, M Cameli, S SpongaAbstract
Background
Right ventricular (RV) dysfunction and RV–pulmonary circulation uncoupling are major determinants of long-term outcomes after heart transplantation (HTx). Conventional RV systolic indices such as TAPSE are highly load-dependent and may inadequately reflect true RV performance in the post-transplant setting. The integration of RV fractional area change (RVFAC) with tricuspid regurgitation peak velocity (Vmax) may provide a more physiologically meaningful marker of RV functional–afterload coupling.
Purpose
To evaluate the prognostic value of the RVFAC/Vmax ratio measured at 6 months after HTx for long-term outcomes, using 5-year cardiovascular mortality as the primary endpoint, and comparing its performance with other RVFAC-based and TAPSE-based indices.
Methods
A total of 131 consecutive heart transplant recipients were screened; 18 patients were excluded due to incomplete echocardiographic or follow-up data, resulting in a final cohort of 113 patients. Receiver operating characteristic (ROC) curve analyses were performed to assess the ability of RVFAC/Vmax, other RVFAC-derived ratios (RVFAC/sPAP, RVFAC/Gmax), and TAPSE-based parameters to predict the primary endpoint of 5-year cardiovascular mortality and secondary endpoints including heart failure (HF) hospitalization, cellular rejection, and humoral rejection. Areas under the curve (AUCs) and optimal cut-off values were calculated.
Results
RVFAC/Vmax showed the strongest prognostic performance among all evaluated parameters. For the primary endpoint, RVFAC/Vmax demonstrated good discrimination for 5-year cardiovascular mortality (AUC up to 0.76), outperforming alternative RVFAC-based indices and TAPSE-derived measures, which showed limited predictive accuracy (AUC ≤0.61). RVFAC/Vmax also provided the highest accuracy for predicting HF hospitalization (AUC 0.76) and showed significant, albeit modest, prognostic value for cellular and humoral rejection at 5 years (AUC approximately 0.61–0.69).
Conclusions
RVFAC/Vmax assessed at 6 months after HTx is a robust marker of RV functional–afterload coupling and the strongest echocardiographic predictor of long-term cardiovascular mortality. Its integration into routine post-transplant surveillance may improve risk stratification and guide individualized follow-up strategies.Graphical abstractFor image description, please refer to the figure legend and surrounding text.ROC curvesFor image description, please refer to the figure legend and surrounding text.