JMIR Publications

ABSTRACT

Background:

Patients hospitalized for heart failure (HF) face a high-risk early post-discharge period.

Objective:

We aimed to develop and internally validate the SAGE-HF score, a simplified risk model incorporating soluble ST2 (sST2), age, and renal function, for predicting 30-day post-discharge major adverse cardiovascular events (MACE).

Methods:

This double-center prospective cohort study included 218 patients hospitalized with HF and 59 healthy controls in Vietnam (June 2025–January 2026). Serum sST2 concentrations were measured at admission using ELISA and compared between HF patients and controls with adjustment for clinical covariates. Among HF patients, the primary endpoint was 30-day MACE, defined as a composite of all-cause death or HF rehospitalization. Candidate predictors were selected based on clinical relevance and univariable screening, and prespecified parsimonious logistic regression models were evaluated using discrimination (AUC), calibration, Brier score, and AIC. Internal validation was performed using bootstrap resampling, and model robustness was assessed using Firth penalized logistic regression. The SAGE-HF score was derived from the final model. All data were analyzed using R environment version 4.5.5.

Results:

Among 287 participants, sST2 concentrations were significantly higher in HF patients than in healthy controls (23.8 ± 8.5 vs. 17.2 ± 8.3 ng/mL, P<.001), with consistent results after adjustment. Among 218 HF patients, 47 (21.6%) experienced 30-day MACE. In multivariable analysis, age (OR 1.04 per year, P=.02), sST2 (OR 1.06 per ng/mL, P=.01), and eGFR (OR 0.98 per unit, P=.02) were independently associated with MACE. The final model demonstrated acceptable discrimination (AUC 0.741, 95% CI 0.664–0.819) and good calibration, with stable performance after bootstrap validation (corrected AUC 0.725). Firth analysis yielded consistent results. The SAGE-HF score showed progressive risk stratification, with predicted 30-day MACE ranging from 7.0% to 60.1%, and maintained acceptable discrimination and calibration.

Conclusions:

The SAGE-HF score, incorporating age, sST2, and eGFR, demonstrated acceptable performance for predicting 30-day MACE after HF hospitalization and may support early risk stratification, pending external validation. Clinical Trial: None