Right Ventricular Free Wall Strain Predicts ATTR Prognosis as Well as Biomarker- Based Staging Systems

Aims The diagnosis of transthyretin amyloidosis (ATTR) significantly impacts the management and prognosis of patients initially presenting with heart failure (HF). Despite recent advances in treatment, prognosticating ATTR remains challenging. We aimed to assess echocardiographic parameters associated with mid-term prognosis in patients with wild-type ATTR using a biomarker staging system as a reference point. Methods and Results We studied 182 consecutive patients with wild-type ATTR (91% male, median age 82 years) who were referred to our center between 2016 and 2022. Using NT- proBNP and eGFR cutoffs, we divided patients into stage I (101 patients, 55.5%), stage II (53, 29.0%), and stage III disease (28, 15.5%). We then compared traditional echocardiographic indices and markers of subclinical ventricular dysfunction (LV global longitudinal strain, RV free wall strain, and LA strain) among groups. Over a fixed follow-up of 18 months, which included treatment with tafamidis 61 mg daily, 48 patients (26.4%) experienced the composite outcome of death or HF hospitalization. When compared with stage I ATTR, the hazard ratio for death or hospitalization was 1.55 (95% CI 0.62–3.86) for stage II ATTR and 4.53 (95% CI 1.66–12.4, p = 0.0116) for stage III ATTR. Among echocardiographic parameters, reduced RV FWS was independently associated with all-cause mortality or HF hospitalization after adjustment for the staging system (HR 2.03, 95% CI 1.07-3.85, p < 0.05). Conclusion RV FWS should be routinely assessed for all patients with ATTR. It is an independent predictor of poor prognosis and provides additional value beyond biomarker staging systems.