Prognostic Value of Baseline and Soluble ST2 Change in Patients With Light Chain Cardiac Amyloidosis

The prognostic significance of dynamic changes in soluble suppression of tumorigenicity-2 (sST2) in patients with light chain cardiac amyloidosis (AL-CA) remains unclear. We aimed to evaluate the prognostic significance of both baseline sST2 and 30-day changes (ΔsST2) in patients with light chain cardiac amyloidosis.

Patients diagnosed with light chain cardiac amyloidosis in Heart Failure Center, Fuwai Hospital (October 2015-May 2024) were enrolled in the entire cohort, with baseline sST2 measured. A prospective subcohort (October 2023-May 2024) also underwent 30-day repeat sST2 measurement. ΔsST2 was defined as the sST2 level at 30 days minus baseline sST2. The primary outcome was all-cause mortality. Prognostic value of both baseline and ΔsST2 was assessed using Kaplan-Meier and Cox models. The relationships between variables and primary outcome were examined with restricted cubic splines.

In the entire cohort with 172 patients included (mean age 60.35±10.21 years; 40.1% women; median follow-up 310 days), higher baseline sST2 levels (>35 ng/mL) were independently associated with increased all-cause mortality risk (adjusted hazard ratio [HR], 1.82 [95% CI, 1.13-2.91], P<0.05). A non-linear association was observed, with risk increasing initially and flattening at higher levels. Among 70 patients in the prospective cohort, 17 primary outcome events occurred. Patients experiencing these events exhibited higher ΔsST2 levels (166.06 [64.37 to 277.03] ng/mL versus 8.37 [-3.08 to 55.83] ng/mL). High ΔsST2 level (>18 ng/mL) was also an independent indicator of worse prognosis (adjusted HR, 9.87 [95% CI, 1.90-51.11], P<0.01).

Elevated baseline sST2 (>35 ng/mL) and short-term increases in sST2 predict poor prognosis in patients with light chain cardiac amyloidosis.