Baseline red cell distribution width-to-albumin ratio and 12-month outcomes in sodium-glucose cotransporter 2 inhibitor-treated heart failure

BACKGROUND: Red cell distribution width-to-albumin ratio (RAR) is associated with heart failure (HF) prognosis, but its incremental value and performance in contemporary sodium-glucose cotransporter 2 inhibitor (SGLT2i)-treated cohorts remain uncertain. METHODS: We re-audited a prospective registry and analyzed 641 unique patients with HF and baseline RAR measured before or on the day of SGLT2i initiation. The 12-month primary endpoint was all-cause death, unplanned hospitalization, or emergency department visit; event-free patients were right-censored at last contact or 365 days. RESULTS: There were 199 first events in the full time-to-event cohort. RAR remained associated with the endpoint after adjustment including N-terminal pro B-type natriuretic peptide [hazard ratio (HR) 1.42 per standard deviation, 95% confidence interval (CI) 1.24-1.61]. The HR for death or HF hospitalization was 1.57 (95% CI 1.33-1.86). Adding RAR increased Harrell's C-index modestly from 0.694 to 0.710 (likelihood-ratio p < 0.001). No statistically significant interaction was observed by SGLT2i type or initiation setting. CONCLUSIONS: Baseline RAR provides modest, confirmatory prognostic information in SGLT2i-treated HF but is not established as a treatment-response biomarker or stand-alone decision rule.