Red blood cell distribution width in patients undergoing transcatheter aortic valve implantation: Implications for outcomes

Background: Red cell distribution width (RDW) is recently emerging as a prognostic indicator in many cardiovascular diseases. However, less is known about its predictive role in patients undergoing transcatheter aortic valve implantation (TAVI). Methods: We retrospectively included very high-risk patients with severe aortic valve stenosis undergoing TAVI between February 2012 and December 2019. Patients were classified according to RDW tertiles. Our primary endpoint was long-term all-cause mortality. The secondary endpoint was a composite of in-hospital major adverse events as defined by the Valve Academic Research Consortium 2 criteria and/or long-term all-cause mortality. Results: A total of 424 patients [median age 83.5 years, 52.6% females] were analysed. After a median follow-up of 1.55 years, all-cause mortality was 25.5%. At the multivariate-adjusted Cox regression analysis, patients in the highest RDW tertile were associated with a higher risk for all-cause mortality [hazard ratio [HR] 1.73, 95%confidence interval [CI] 1.02-2.95] compared with the lowest tertile. When considering RDW as a continuous variable, we found an 11% increased risk in overall mortality [HR 1.11, 95% CI 1.00-1.24] for each increased point in RDW. The highest RDW tertile was also independently associated with the occurrence of the composite endpoint [odds ratio [OR] 2.10, 95% CI 1.17-3.76] compared with lower tertiles. Conclusions: In our cohort, elevated basal RDW values were independent predictors of increased long-term mortality and higher rate of in-hospital adverse events. The inclusion of a routinely available biomarker as RDW, may help the pre-operative risk assessment in potential TAVI candidates and optimise their management.