Abstract
Red blood cell distribution width (RDW) has recently been reported to be related to the prognosis of patients with myocardial infarction, heart failure, and old age. However, there have been few reports on the relationship between RDW and peripheral arterial disease (PAD). This study was performed to clarify the significance of RDW in the diagnosis of PAD and the prognosis of PAD patients. Two thousand forty-six patients over 40 years of age who underwent measurements of ankle/brachial pressure index (ABI) and RDW, hemoglobin (Hb) concentration, and mean corpuscular volume (MCV) from January 2009 to December 2013 were included in this study. The lower right or left ABI was recorded, and PAD was defined as ABI ≤ 0.90. The mean ABI was 1.05 ± 0.17, and the number of patients with ABI ≤ 0.90 (PAD patients) was 288 (14.1%). The mean RDW was 14.4 ± 1.7. There was a significant correlation between ABI and RDW (y = –0.012x + 1.227, x: RDW, y: ABI, R = 0.125, p < 0.0001). The age and RDW of PAD patients were significantly higher than those of non-PAD patients, and the Hb concentration of PAD patients was significantly lower than that of non-PAD patients. The age, RDW, and Hb concentration were significant independent factors related to ABI ≤ 0.90 in multivariate analysis. The overall survival (OS) of PAD patients was significantly lower than that of non-PAD patients; in addition, the OS of PAD patients with RDW ≥ 15.1 was significantly lower than that with RDW ≤ 15.0. This difference was remarkable in non-anemic patients. In conclusion, RDW is useful for the diagnosis and prognosis of PAD.
