A new staging system using right atrial strain in patients with immunoglobulin light‐chain cardiac amyloidosis

Abstract Aims There are minimal data on the prognostic impact of right atrial strain during the reservoir phase (RASr) in patients with immunoglobulin light‐chain (AL) cardiac amyloidosis. Methods and results Among 78 patients who were diagnosed with AL cardiac amyloidosis at Kumamoto University Hospital from 2007 to 2022, 72 patients with sufficient two‐dimensional speckle tracking imaging data without chemotherapy before the diagnosis were retrospectively analysed. During a median follow‐up of 403 days, 31 deaths occurred. Age and the rate of male sex were not significantly different between the all‐cause death group and the survival group (age, 70.4 ± 8.8 years vs. 67.0 ± 10.0 years, P = 0.14, male sex, 65% vs. 66%, P = 0.91). The estimated glomerular filtration rate (eGFR) was significantly lower, and B‐type natriuretic peptide (BNP) and high sensitivity cardiac troponin T (hs‐cTnT) were significantly higher, in the all‐cause death group versus the survival group (eGFR, 48.2 ± 21.0 mL/min/1.73 m 2 vs. 59.4 ± 24.4 mL/min/1.73 m 2 , P 311.2 pg/mL) had a significantly high probability of all‐cause death (both, P < 0.01). We devised a new staging score by adding 1 point if RASr decreased or BNP levels increased more than each cut‐off value. The HR for all‐cause death using score 0 as a reference was 5.95 (95% CI: 1.19–29.79; P < 0.05) for score 1 and 23.29 (95% CI: 5.37–100.98; P < 0.01) for score 2. Conclusions The new staging system using RASr and BNP predicted prognosis in patients with AL cardiac amyloidosis.