Prognostic value of CMR-derived extracellular volume in AL amyloidosis: a multicenter study

This study aimed to assess the prognostic value of cardiac magnetic resonance (CMR) variables and compare them with biological and echocardiographic markers in patients with AL cardiac amyloidosis (CA). We conducted a prospective study across three tertiary centres, where patients underwent clinical examination, blood tests, echocardiography, and CMR. The primary endpoint was all-cause mortality. A total of 176 patients with AL CA were included, with a median age of 68 years (IQR 58-75). According to the 2004 Mayo Clinic staging, 121 patients (69%) were in stage 3. During a median follow-up of 22 months (IQR 8–48), 45 patients died, and 55 were hospitalized for heart failure. Patients who died had higher NT-proBNP and troponin levels, and lower LVEF, cardiac output, and longitudinal strain. Among CMR variables, extracellular volume (ECV) was most strongly associated with all-cause mortality. In multivariate Cox models, including Mayo Clinic staging, ECV ≥ 0.45 was independently associated with mortality (HR 2.36, CI 95% 1.47–5.60) and also with heart failure hospitalizations (HR 4.10, 95%CI 2.15–8.8). ECV is a powerful predictor of outcomes in AL CA, providing additional prognostic value on top of Mayo Clinic staging.