RESUMO
Red cell distribution width (RDW) is a measurement of the variation in size, as well as an index of heterogeneity of erythrocytes, which is used in combination with other hematologic parameters as an aid to the differential diagnosis of hypochromic anemia. RDW could also serve as a biomarker in the diagnosis and prognosis patients with cardiovascular diseases. However, it is unclear whether the increased heterogeneity is the cause or consequence of other pathophysiological conditions such as renal failure, malnutrition, inflammation and oxidative stress, which among other conditions are actively involved in the genesis and progression of cardiovascular diseases. The aim of this review is to show and discuss recent evidence about the role of RDW measurement as an aid in the diagnosis and prognosis of patients with such diseases. Besides being a simple, inexpensive and routinely measured parameter, it could help in the stratification of patients according to their risk in clinical practice.