Department of Cardiology, Antwerp University Hospital, Edegem, Belgium.
Eur J Heart Fail. 2013 Jul;15(7):756-62. doi: 10.1093/eurjhf/hft068. Epub 2013 May 2.
Red cell distribution width (RDW), a measure of variability in red blood cell size, is a novel prognostic marker in chronic heart failure (CHF). Iron deficiency contributes to elevated RDW. In the FAIR-HF trial, i.v. ferric carboxymaltose (FCM) improved the 6 min walk test (6MWT) distance in iron-deficient CHF patients. We studied the effect of FCM on RDW and the relationship between RDW and 6MWT distance.
In FAIR-HF, iron-deficient CHF patients were randomized to FCM or placebo in a 2:1 ratio. From the total cohort (n = 459), we included 415 patients in whom RDW values and 6MWT distance were available for baseline and at least one follow-up visit (after 4, 12, and 24 weeks). Baseline RDW was higher in anaemic (haemoglobin <12 g/dL) compared with non-anaemic patients [15.2% (14.0-16.8) vs. 14.2% (13.4-15.4), P < 0.0001, median (interquartile range)]. In multivariate analysis, RDW was significantly associated with transferrin saturation (P < 0.001) and C-reactive protein levels (P = 0.002). Treatment with FCM led to a biphasic response; RDW increased within 4 weeks (+0.54% absolute change from baseline, P = 0.01) but fell to values below the placebo group after 24 weeks (-1.0 %, P = 0.03). The 6MWT distance and RDW were inversely related at baseline (r = -0.30, P < 0.0001). In all patients, the increase in 6MWT distance after 24 weeks was significantly correlated with a decrease in RDW (r= -0.25, P < 0.0001), even after adjustment for changes in haemoglobin.
Iron deficiency in CHF is associated with high RDW, even after adjustment for the presence of anaemia. Treatment with i.v. FCM in iron-deficient CHF patients decreases RDW.
红细胞分布宽度（RDW）是红细胞大小变异的一种衡量指标，是慢性心力衰竭（CHF）的一种新的预后标志物。铁缺乏会导致 RDW 升高。在 FAIR-HF 试验中，静脉注射羧基麦芽糖铁（FCM）可改善缺铁性 CHF 患者的 6 分钟步行试验（6MWT）距离。我们研究了 FCM 对 RDW 的影响以及 RDW 与 6MWT 距离之间的关系。
在 FAIR-HF 中，将缺铁性 CHF 患者按 2:1 的比例随机分为 FCM 组或安慰剂组。在总队列（n = 459）中，我们纳入了 415 名基线和至少一次随访（4、12 和 24 周后）时可获得 RDW 值和 6MWT 距离的患者。与非贫血患者相比，贫血（血红蛋白 <12 g/dL）患者的基线 RDW 更高[15.2%（14.0-16.8）比 14.2%（13.4-15.4），P < 0.0001，中位数（四分位距）]。多变量分析显示，RDW 与转铁蛋白饱和度（P < 0.001）和 C 反应蛋白水平（P = 0.002）显著相关。FCM 治疗导致双相反应；4 周内 RDW 增加（与基线相比绝对值增加 0.54%，P = 0.01），但 24 周后降至安慰剂组以下（-1.0%，P = 0.03）。基线时 6MWT 距离和 RDW 呈负相关（r = -0.30，P < 0.0001）。在所有患者中，24 周后 6MWT 距离的增加与 RDW 的降低显著相关（r = -0.25，P < 0.0001），即使在调整血红蛋白变化后也是如此。
CHF 中的铁缺乏与高 RDW 相关，即使在调整贫血存在的情况下也是如此。静脉注射 FCM 治疗缺铁性 CHF 患者可降低 RDW。
