Assessing right ventricular dysfunction in wild-type transthyretin amyloid cardiomyopathy: echocardiographic predictor of clinical outcomes

Abstract Background Wild-type transthyretin amyloid cardiomyopathy (wtATTR-CM) is a progressive infiltrative disorder characterized by amyloid deposition in the myocardium, with significant involvement of the right ventricle (RV). RV dysfunction is prevalent in wtATTR-CM and has been associated with adverse clinical outcomes. Although several echocardiographic parameters are used to assess RV function, the most robust prognostic indicator remains to be clarified. Purpose This study aimed to determine which echocardiographic parameter of right ventricular function best predicts adverse outcomes in patients with wtATTR-CM. Methods A retrospective cohort of 111 patients diagnosed with wtATTR-CM was analyzed. Baseline echocardiographic measurements were compared between patients who reached the composite primary endpoint (heart failure hospitalization and/or all-cause mortality) and those who did not. Parameters assessed included tricuspid annular plane systolic excursion (TAPSE), systolic velocity of the tricuspid annulus (S′), fractional area change (FAC), and right ventricular global longitudinal strain (RVGLS). Receiver operating characteristic (ROC) curves were used to identify optimal cutoff values, and multivariable Cox regression analysis was performed to identify independent predictors of the composite endpoint. Results The study population was predominantly male (74%), with a mean age of 81 ± 5 years. Median follow-up duration was 31 months (IQR 16–39). Patients who experienced the primary endpoint exhibited significantly impaired RV function across all parameters: - S′: 9.66 ± 2.90 cm/s vs. 12.16 ± 3.60 cm/s (p0.001) - TAPSE: 16.12 ± 4.73 mm vs. 18.59 ± 4.33 mm (p=0.007) - FAC: 32.12 ± 9.42% vs. 39.21 ± 9.23% (p0.001) - RVGLS: –10.50 ± 4.09% vs. –12.72 ± 4.64% (p=0.011) Optimal cutoff values identified by ROC analysis were S′ ≤ 11 cm/s, TAPSE ≤ 18.7 mm, FAC ≤ 39.1%, and RVGLS ≥ –14.5%. In multivariate analysis, FAC was the only echocardiographic measure independently associated with the composite endpoint (hazard ratio HR 3.98; 95% confidence interval CI 1.36–11.63; p=0.012). Conclusions Among the right ventricular echocardiographic parameters studied, fractional area change (FAC) emerged as the most reliable and independent predictor of adverse clinical outcomes in patients with wtATTR-CM. These findings suggest that FAC should be prioritized in the echocardiographic evaluation of RV function in this patient population and may aid in risk stratification and therapeutic decision-making.