Abstract 17003: Post-Operative Expansion of the Red Cell Distribution Width Powerfully Predicts Poor Outcomes After Aortic Valve Surgery

Abstract

Red cell distribution width (RDW), an index of the variation in red cell volume, is a surrogate of many aberrations (iron deficiency, inflammation, malnutrition and oxidative stress) that could impair early and late outcomes after aortic valve replacement (AVR). Whilst an increase In RDW powerfully predicts morbidity and mortality in heart failure and PCI patients, its prognostic relevance in AVR cohorts is unknown. Methods: We analysed the relation of changes in RDW over time to outcomes in 1177 AVR patients (mean [±SD] age 68±13 years, RDW 14.1±1.6%, hemoglobin 12.9±1.8g/dL, EuroSCORE 6±3, 63% male, 24% with ejection fractions [EF]<50%, 60% aortic stenosis, 17% aortic regurgitation, 17% mixed aortic disease). Results: Pre-operatively, 19% of patients had an RDW≥15%. This group were more likely to be female (43% vs 36%), non-elective cases (47% vs 26%) with poorer LVEFs (35% vs 21% with LVEF<50%), have greater congestive symptoms (17 vs 7), and spend more days ventilated (1.7 vs 1.2) and hospitalized (17 vs 14) (all P<0.05). Over a median (±IQR) stay of 8±5 days, 906 (77%) patients had an increase in RDW and 39 (3.3%) died in hospital. Early mortality was related to an increase in RDW over time (HR 1.4, CI:1.2-1.5, P1.6% optimally predicting death (HR 4.0, CI:2.0-8.0, P<0.0001, Figure A ). This was independent of age, LVEF, EuroSCORE, Parsonnet score, hemoglobin and creatinine. Of the 1138 patients who survived to discharge, 88(8%) died over a median follow-up of 4 years. Late mortality was also related to a rise in RDW (HR 1.3, CI: 1.2-1.4, P0.9% optimally predicting death (HR 3, CI:2-5, P<0.0001, Figure B ), independently of all covariates. Conclusions: An Increase in the RDW post-AVR is associated with an amplified risk of early and late surgical mortality. Understanding and ameliorating the drivers of RDW expansion in this cohort may increment survival.