Transfusion dependency as an independent predictor of mortality in myelodysplastic syndromes: Interaction across IPSS-R risk strata in a retrospective cohort.

BACKGROUND: Transfusion dependency (TD) is a recognized adverse prognostic marker in myelodysplastic syndromes (MDS), yet its predictors and survival impact remain poorly characterized in Saudi Arabian patients. AIM: To identify clinical and hematologic predictors of TD and evaluate its impact on overall survival in a cohort of Saudi MDS patients. METHODS: This single-center retrospective cohort study included 180 adult MDS patients diagnosed per the WHO 2022 criteria. Multivariable logistic regression identified independent predictors of TD. Kaplan-Meier curves and Cox proportional hazards regression assessed survival outcomes. Mediation and interaction analyses explored TD's role within established risk frameworks. RESULTS: Sixty percent of patients were transfusion dependent. Lower hemoglobin (OR = 0.40 per g/dL, p < .001) and poor cytogenetic risk (OR = 6.10, p = .002) were the strongest independent predictors of TD. Transfusion-dependent patients had significantly shorter median survival (38 vs. 51 months, p < .001). After multivariable adjustment, TD remained an independent predictor of mortality (HR = 2.67, p < .001). A significant interaction between TD and IPSS-R category was identified, while mediation analysis indicated TD operates as a parallel rather than mediating pathway. CONCLUSION: TD is an independent, powerful predictor of mortality in MDS, driven primarily by severe anemia and poor cytogenetics. Dynamic monitoring of transfusion status is essential across all risk strata.