Background: Whether the hematocrit is implicated in the pathogenesis of slow coronary flow (SCF) is not known.
Methods: To evaluate the correlation between the hematocrit and SCF, we studied 367 patients with angiographically near-normal coronary arteries. They were divided into four quartiles based on the hematocrit. The corrected thrombolysis in myocardial infarction frame count (TFC) was used to document velocity of coronary flow.
Results: From the first through to the fourth quartile, the percentage of males and those who smoked as well as serum levels of creatinine, uric acid and triglyceride increased (p < 0.001), whereas the age and level of high-density lipoprotein-cholesterol decreased (p < 0.05). The proportions of SCF in the quartiles increased (55.4, 60.9, 77.2 and 85.7%, respectively, p < 0.001). Multivariate analyses revealed that the corrected TFC for the left anterior descending artery (LAD) (p < 0.001; B = 0.065; 95% confidence interval (CI), 0.038-0.093; beta = 0.199) and the proportion of SCF in the LAD (p < 0.001; B = 1.343; 95% CI 0.704-1.983; beta = 0.174) were correlated with the hematocrit after adjustment for confounding factors.
Conclusion: The hematocrit is positively correlated with the corrected TFC for the LAD, which suggested that an increase in the hematocrit may contribute to the pathophysiology of SCF.
Keywords: Hematocrit; risk factors; slow coronary flow.