Plateletcrit and red cell-distribution width are independent predictors of the slow coronary flow phenomenon

Background and purpose: Endothelial dysfunction may play a role in the pathogenesis of the slow coronary flow (SCF) phenomenon. A detailed examination of blood cellular components has not been performed for this condition. We investigated the relationship between SCF and whole blood cell counts. Method: Records of 17,315 patients who underwent coronary angiography between January 2006 and December 2012 were evaluated retrospectively. A total of 146 patients with SCF were compared with 148 patients with normal coronary arteries according to demographic data, complete blood count, and biochemical parameters. Results: The following parameters were significantly higher in SCF patients than in patients with normal coronary arteries: percentage of smokers (36.3% vs. 25%, p = 0.036), body mass index (26.69 +/- 2.84 vs. 26.07 +/- 3.15, p = 0.049), white blood cells (WBCs) (7.52 +/- 1.43 x 10(3) mm(-3) vs. 7.01 +/- 1.42 x 10(3) mm(-3), p = 0.002), red cell distribution width (RDW) (13.68 +/- 1.42% vs. 13.15 +/- 1.13%, p < 0.001), platelets (250.29 +/- 50.96 x 10(3) mm(-3) vs. 226.10 +/- 38.02 x 10(3) mm(-3), p < 0.001), plateletcrit (PCT) (0.214 +/- 0.40% vs. 0.184 +/- 0.29%, p < 0.001), mean platelet volume (8.63 +/- 1.10 fL vs. 8.22 +/- 0.83 fL, p < 0.001), platelet distribution width (PDW) (16.58 +/- 0.76% vs. 16.45 +/- 0.57%, p = 0.028), and neutrophils (4.44 +/- 1.25 x 10(3) mm(-3) vs. 4.12 +/- 1.24 x 10(3) mm(-3), p = 0.029). Positive PCT values [odds ratio (OR), 4.165; 95% confidence interval (CI), 2.493-6.959; p < 0.001) and RDW (OR, 1.304; 95% Cl, 1.034-1.645; p = 0.025) were independent predictors of SCF. Conclusion: Although within the normal range, the increased numbers of WBCs and neutrophils in patients with SCF suggest that SCF may be a subclinical inflammatory condition. Furthermore, increased RDW and PDW in SCF patients may cause microvascular blood flow resistance due to impaired cell deformability. The PCT provides reliable data regarding total platelet mass and may be a useful predictor of SCF. (C) 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.