Serial Red Cell Distribution Width and Mortality After TAVR: An Observational Cohort Study

Background/Objectives: Preprocedural red cell distribution width (RDW) is associated with mortality after transcatheter aortic valve replacement (TAVR), but the prognostic relevance of serial measurements and native leaflet morphology remains uncertain. Methods: This single-center retrospective cohort included 1369 patients who underwent native-valve TAVR from January 2019 to October 2023. The primary analysis evaluated baseline RDW-coefficient of variation (RDW-CV) and mortality in the overall cohort. Exploratory landmark analyses examined postprocedural RDW-CV changes among survivors with repeat measurements. Valve-disease phenotype and leaflet morphology were evaluated as potential effect modifiers. Results: During a median reverse Kaplan–Meier follow-up of 58.7 months, 196 patients died. Higher baseline RDW-CV was associated with mortality over all follow-up (adjusted HR per 1-SD increase, 1.17; 95% CI, 1.02–1.34; p = 0.022). After adjustment for baseline RDW-CV and clinical covariates, greater increases at 3 months (HR per window-specific 1-SD increase, 1.53; 95% CI, 1.20–1.94; p < 0.001) and 6 months (HR, 1.37; 95% CI, 1.08–1.73; p = 0.009) were associated with subsequent mortality. Exploratory analysis suggested a stronger 6-month association in bicuspid than tricuspid valves (HR, 2.47 [95% CI, 1.65–3.69] vs. 1.02 [0.75–1.40]; interaction p = 0.002). Adding 6-month RDW-CV change increased the cross-validated 2-year AUC from 0.628 to 0.651. Conclusions: Baseline RDW-CV was associated with mortality after TAVR. Among patients with repeat testing, increases at 3 and 6 months were associated with subsequent mortality, with an exploratory stronger association in bicuspid aortic valve. Standardized prospective sampling is required to confirm these longitudinal findings.