Impact of red blood cell transfusion volume on long-term mortality after transcatheter aortic valve replacement.

Backgrounds: The relationship between red blood cell (RBC) transfusion volume and long-term survival outcomes following transcatheter aortic valve replacement (TAVR) remains inadequately characterized. This study sought to investigate the clinical impact of perioperative transfusion and identify critical thresholds for transfusion volume in predicting mortality risk after TAVR. Methods: In this retrospective cohort analysis, patients undergoing TAVR at a tertiary cardiac center between April 2012 and September 2023 were consecutively enrolled and stratified by transfusion status. Multivariate Cox regression models were employed to identify prognostic factors for mortality. The primary outcome was all-cause mortality at 1-year post-TAVR. Results: Of 1,758 included patients, 141 (8.02%) required RBC transfusions. Transfused patients exhibited higher risk profiles, female predominance, advanced age, anemia, chronic kidney disease at baseline, and increased rates of life-threatening/major bleeding, stroke, and stage 3 acute kidney injury. These patients also demonstrated elevated 30-day and 1-year mortality rates. While transfusion status (P = 0.690) and anemia (P = 0.188) showed no independent association with 1-year mortality, total transfusion volume emerged as a significant independent predictor (adjusted hazard ratio 1.07, 95% CI: 1.02-1.12; P = 0.008), with 4.5 units identified as the optimal threshold for mortality risk stratification. Life-threatening/major bleeding events constituted the sole independent predictor of transfusion volumes exceeding 4.5 units (P = 0.039). Conclusions: Elevated transfusion volumes significantly correlate with increased long-term mortality risk in transfused TAVR recipients, primarily mediated by life-threatening hemorrhagic complications. These findings underscore the importance of implementing bleeding mitigation strategies to minimize transfusion requirements and improve clinical outcomes.