Abstract 19569: Red Cell Distribution Width Is An Independent Predictor Of Mortality In Patients With Periphearal Artery Disease
Introduction: Increased red cell distribution width (RDW), a marker of anisocytosis, has been associated with adverse outcomes in multiple settings.
Hypothesis: We hypothesized that RDW would be predictive of all-cause mortality in patients with peripheral artery disease (PAD).
Methods: We studied 14446 adults referred for lower-extremity arterial evaluation at Mayo Clinic from 1/97 to 12/07, with follow-up through 9/09. We defined PAD as either ankle-brachial index (ABI) ≤0.9, or presence of non-compressible vessels (ABI ≥1.4 or ankle BP ≥ 255 mmHg). Normal ABI was defined as 1.0–1.3. Comorbidities were ascertained from the electronic medical record using ICD-9-CM codes and Natural Language Processing. RDW was obtained from the complete blood count drawn at the time of arterial evaluation. Mortality was ascertained using Accurint® database. The association between RDW and all-cause mortality was analyzed by multivariable Cox proportional hazards regression.
Results: The majority (97.5%) of patients were white, 58.7% were men and mean age was 68.2±12.7 y. Prevalence of PAD was 71.3% (low ABI 54.5% and non-compressible vessels 16.8%). RDW was highest in patients with non-compressible vessels (14.3±2.1% vs 13.8±1.8% in low ABI and 13.5±1.6% in normal ABI; age and sex adjusted Ρ <0.0001). During a mean follow up of 5.8±3.1 y, 3980 (28%) deaths occurred. After adjustment for age, sex and comorbidities, higher RDW was associated with all-cause mortality in the entire sample and in each of the 3 study groups (Ρ <0.0001 for each) (Table).
Conclusions: RDW is a significant predictor of mortality and may be a clinically useful prognostic marker in patients referred for non-invasive vascular evaluation, including the subset with PAD.
- © 2010 by American Heart Association, Inc.