Red Cell Distribution Width as an Independent Predictor of Mortality in Patients Undergoing Transcatheter Aortic Valve Implantation in a Large, Long-Term Cohort

Background: The aim of this study was to estimate the long-term prognostic value of baseline red cell distribution width (RDW) in patients undergoing transcatheter aortic valve implantation (TAVI).

Methods: In a large, long-term prospective single center study, we determined the impact of baseline RDW on outcome in a cohort of 1,029 patients with aortic stenosis undergoing transfemoral TAVI. Collected data included patient characteristics, medical background, left ventricle ejection fraction (LVEF), frailty scores, Society of Thoracic Surgeons (STS) score, periprocedural laboratory results and long term clinical outcomes (up to 7.5 years). We divided our cohort into tertiles according to RDW values.

Results: There were 43.9% men. Their mean age (±SD) was 83.1±6.3, mean STS-score was 4.2±3.1 and mean estimated LVEF was 55.7±8.4%. Mean pre-TAVI RDW levels were 15.3±3.2%. Patients with RDW<14.2% (n=358), 14.2%≤RDW≤15.6% (n=345) and RDW>15.6% (n=326) had a 1-year mortality rate of 6%, 7% and 17%, respectively (p<0.001) and a 5-year mortality rate of 18%, 24% and 39%, respectively (P<0.001). Baseline RDW>15.6% predicted death (HR 2.2, 95% CI 1.6 to 2.9, p<0.0001) independently of age, estimated LVEF, gradients, frailty, STS-score, hemoglobin levels and glomerular filtration rate (GFR).

Conclusion: Elevated RDW is a strong independent predictor of mortality in the short and long term after TAVI. Additional research is needed in order to clarify the mechanisms responsible for this finding.