Red cell distribution width and its relationship with global longitudinal strain in patients with heart failure with reduced ejection fraction: a study using two-dimensional speckle tracking echocardiography

Background: Red cell distribution width (RDW) is a measurement of size variability of the red blood cells and has been shown to be a powerful predictor of prognosis in heart failure (HF). Recently, global longitudinal strain (GLS) emerged as a more accurate marker of left ventricular (LV) systolic function. Aim: We aimed to assess the relationship between RDW and standard echocardiographic parameters and LV global strain measured by two-dimensional (2D) speckle tracking echocardiography in patients with HF with reduced EF (HFrEF). Methods: Fifty-nine HF patients with an EF < 50%, and 40 age-matched controls with normal EF were included in the study. Standard and 2D strain imaging examinations were performed. Blood tests including RDW were scheduled on the same day as the echocardiographic study. Results: Left atrial volume index, LV end-systolic and end-diastolic dimensions, and E/A and E/e' ratios were higher and LVEF together with LV GLS were significantly lower in the HFrEF group. RDW showed positive correlations with log B-type natriuretic peptide (r = 0.45, p = 0.0001), left atrial volume index (r = 0.38, p = 0.001), LV end-diastolic dimensions (r = 0.37, p = 0.001), and E/e' (r = 0.33, p = 0.005) and negative correlations with haemoglobin (r = -0.54, p = 0.0001), LVEF (r = -0.27, p = 0.004) and finally LV GLS (r = -0.41, p = 0.001). HFrEF patients were divided into two groups based on the median RDW value. Patients with higher than median RDW had significantly lower GLS despite similar EF. Conclusions: Elevated RDW is associated with poorer LV deformation assessed by speckle tracking echocardiography in HF patients with similar EF. Therefore, the degree of anisocytosis could be used as an additional marker to identify these high-risk patients as well as improve treatment strategy.