Red Blood Cell Distribution Width as an Effective Tool for Detecting Fatal Heart Failure in Super-elderly Patients

Abstract
Objective Red blood cell distribution width (RDW) is a numerical measure of erythrocyte size variation. It has been recently reported to be an independent prognostic marker of heart failure (HF). Previous studies on RDW were mostly designed for middle-aged and elderly patients (60-79 years old), therefore, there is no established limit for super-elderly patients (≥80 years old). The purpose of this study was to evaluate RDW as an effective tool to detect fatal HF in super-elderly patients. Methods The medical records and death certificates of 160 consecutive patients admitted to the Department of Cardiology in Juntendo Tokyo Koto Geriatric Medical Center and who died from June 2002 to October 2010 were reviewed. The causes of death were reviewed, and the factors, including RDW, that might have been related to the fatal HF were evaluated using multivariate logistic regression analysis. Results HF was the major cause of death [52 patients (32.5%), 29 females, age 84.0±7.5 years], followed by pneumonia (18.8%, 30/160), and acute myocardial infarction (16.3%, 26/160). The most common cause of HF was atrial fibrillation (36.6%, 19/52), followed by hypertensive heart disease (19.2%, 10/52) and valvular disorders (17.3%, 9/52). The multivariate logistic regression analysis found that a high RDW (≥16.5%) was an independent factor related to fatal HF (OR 2.36, 95% CI 1.10, 5.04, p=0.03). Conclusion HF was the major cause of death, and RDW ≥16.5 was significantly associated with fatal HF in super-elderly patients.