Red Blood Cell Distribution Width is Independently Correlated With Diurnal QTc Variation in Patients With Coronary Heart Disease

To investigate the relationship between red blood cell distribution width (RDW) and diurnal corrected QT (QTc) variation in patients with coronary heart disease. This retrospective study included 203 patients who underwent coronary angiography between February 2013 and June 2014. RDW values and dynamic electrocardiography (Holter) results were collected to investigate the relationship between RDW and diurnal QTc variation. Patients were separated into three groups (A, B, and C) by binning their RDW values in an ascending order. RDW values, coronary artery scores and diurnal QTc variations were significantly different among these groups (P < 0.05). While coronary artery scores gradually rose with increased RDW, diurnal QTc variation decreased. Pearson's correlation analysis was applied to control for confounding factors, and multiple correlation analysis showed that coronary artery score was positively correlated with RDW (r = 0.130, P = 0.020), while it was not correlated with the diurnal QTc variation (r = −0.226, P = 0.681). RDW was negatively correlated with diurnal QTc variation (r = −0.197, P = 0.035). RDW is independently associated with diurnal QTc variation in patients with coronary heart disease.