Abstract 15483: Red Cell Distribution Width as an Independent Predictor of Exercise Intolerance and Ventilatory Inefficiency in Patients with Chronic Heart Failure

Abstract

Background: Peak oxygen uptake (peak VO₂) and ventilatory efficiency (VE/VCO₂ slope) have proven to be strong prognostic markers in patients with chronic heart failure (CHF). Recently, increased red cell distribution width (RDW) has emerged as an additional predictor of poor outcome in CHF. We investigated the relationship between RDW and cardiopulmonary exercise test (CPET) parameters.

Methods: One hundred eighteen ambulatory patients with CHF (92 men, 54 ± 11 years, mean ejection fraction 45.6 ± 14.5%) were enrolled. Patients were divided into RDW tertile and clinical, laboratory, echocardiographic parameters and CPET results were analyzed.

Results: Compared with those in the lowest tertile (RDW<12.7%), patients with highest tertile (RDW>13.1%) had significantly lower peak VO₂ (22.9 vs. 28.3 mL/kg/min, p=0.001) and higher VE/VCO₂ slope (29.3 vs. 25.4, p=0.005). Multivariate regression analysis revealed RDW was an independent predictor of peak VO₂ (β=-0.210, p=0.011) and VE/VCO₂ slope (β=0.240, p=0.008) when controlled for age, gender, hemoglobin, body mass index, albumin, renal function, left ventricular ejection fraction and early mitral inflow velocity to early diastolic mitral annular velocity (E/E).

Conclusions: Higher RDW is independently related to exercise intolerance and ventilatory inefficiency, which are well known prognostic markers in CHF. These findings may explain the novel relationship between RDW and CPET parameters in stable ambulatory CHF patients.