Abstract / Summary
Abstract Background Anemia management in critically ill hemodialysis (HD) patients with chronic kidney disease (CKD) primarily relies on static hemoglobin (Hb) measurements, which fail to capture clinically meaningful dynamic changes. This study aimed to identify distinct longitudinal Hb trajectory patterns during the first 30 days of intensive care unit (ICU) admission and evaluate their associations with short- and long-term all-cause mortality in this vulnerable population. Methods This retrospective cohort study analyzed 1,384 maintenance HD patients from the MIMIC-IV database (2008–2019). Latent class growth modeling (LCGM) was applied to serial Hb measurements within 30 days post-ICU admission to define trajectory subgroups. Key mortality covariates were selected using the least absolute shrinkage and selection operator (LASSO) regression. Multivariable Cox models, adjusted for these covariates, assessed associations with mortality at 30, 60, 90, and 365 days. Multivariable Cox proportional hazards models adjusted for these covariates and validated for the proportional hazards assumption via Schoenfeld residual test were used to assess associations between Hb trajectories and mortality at 30, 60, 90, and 365 days. Subgroup analyses and missing data impact assessment were conducted to verify result robustness. Results Three distinct Hb trajectories were identified: “Stable-Low”(37.6%), “Moderate-Decline” (55.9%), and “Rapid-Deterioration” (6.5%). LASSO regression selected seven key covariates for adjustment. Compared to “Stable-Low”, “Rapid-Deterioration” was associated with a 63% increased 30-day mortality risk (adjusted HR[aHR] = 1.63, 95% CI: 1.07–2.49) and a 68% increased risk of 60-day mortality (aHR = 1.68, 95% CI: 1.14–2.48, P = 0.009), but this excess risk attenuated over time and became non-significant at 90 days and 365 days. In contrast, the “Moderate-Decline”group exhibited a persistent 35% increased risk of 60-day mortality (aHR = 1.35, 95% CI: 1.09–1.67, P = 0.006) and a significant 24% increased risk of 90-day mortality (aHR = 1.24, 95% CI: 1.01–1.51, P = 0.039). Subgroup analyses confirmed the robustness of the associations and indicated that the risk associated with “Rapid-Deterioration” was significantly greater in patients aged ≥ 65 years (P for interaction = 0.026). Conclusion Dynamic Hb trajectories during the early ICU period provide superior, time-sensitive prognostic stratification compared to static values. The "Rapid-Deterioration" pattern should prompt urgent evaluation for acute complications, while "Moderate-Decline" indicates a need for long-term management optimization, supporting a shift towards trajectory-informed care.