Abstract 19134: Higher Red Blood Cell Distribution Width Predicts Cardiovascular Events in Patients with Heart Failure with Normal Left Ventricular Ejection Fraction
Background Red blood cell distribution width (RDW) is a quantitative measure of the variability in size of the circulating erythrocytes, and is associated with increased risk of adverse cardiovascular (CV) outcomes in patients with heart failure (HF) with reduced left ventricular ejection fraction (LVEF). We investigated whether the RDW levels could predict future CV events in patients with HF with normal LVEF (HFNEF).
Methods We measured plasma levels of B-type natriuretic peptide (BNP) and RDW sampled from peripheral vein following an overnight fast in 319 patients with symptomatic HF (New York Heart Association (NYHA)-II: n=244, -III, IV; n=75, age 71±10, LVEF 63±6%, BNP 121 [33-302] pg/ml]). HFNEF patients were followed until occurring CV events (CV death, non-fatal myocardial infarction and ischemic stroke, unstable angina pectoris, hospitalization for HF, or coronary revascularization).
Results RDW levels were higher in patients with moderate to severe symptoms (NYHA III or IV) compared to mild symptoms (NYHA II) (14.1±1.4 vs. 13.4±1.0%, P<0.001). RDW positively correlated with BNP (r=0.42, P<0.001), and C-reactive protein (r=0.28, P<0.001), whereas RDW inversely correlated with hemoglobin levels (r=-0.30, P<0.001), LVEF (r=-0.22, P<0.001), and estimated glomerular filtration rate (r=-0.21, P<0.001). During a mean follow-up of 20 months, 59 patients developed CV events. RDW levels was significantly higher in patients with CV events than those without events (13.9±1.5 vs. 13.5±1.1%, P=0.03). Kaplan-Meier analysis demonstrated a significantly higher probability of CV events in the higher RDW group (n=34) than in the lower RDW group (n=285) by the cut-off value as 15.0 (log rank test P<0.001). Multivariate Cox hazard analysis identified higher RDW [hazard ratio (HR) 2.00, 95% confidence interval (CI) 1.04-3.88, P=0.04], higher NYHA class (NYHA III or IV, HR 2.69, 95% CI 1.53-4.75, P=0.001), and higher BNP levels (a cut-off value 100pg/ml, HR 2.25, 95% CI 1.16-4.37, P=0.02), but not hemoglobin levels, as independent predictors of the future CV events.
Conclusions Levels of RDW correlated with HF severity, LVEF, anemia, inflammation, and renal function, and higher RDW predicted the future CV events in patients with HFNEF.
- © 2012 by American Heart Association, Inc.