Correlation analysis of hematocrit level and coronary heart disease in patients with chest pain: a case-control study.

Background: At present, there is controversy about whether hematocrit (HCT) is a risk factor for coronary heart disease (CHD). We try to explore the effect of low or high HCT on CHD, and analyze its mechanism from the perspective of hemodynamics.

Methods: According to the exclusion criteria, a total of 3,200 patients who underwent coronary angiography or coronary computed tomography angiography (CTA) for typical post-exercise chest pain/dyspnea; atypical chest pain; or noncardiac chest pain or asymptomatic at Beijing Anzhen Hospital Affiliated to Capital Medical University from October 2019 to October 2021 were selected as research subjects. A coronary artery stenosis of 50% was used as the criterion for determining CHD. A total of 1,660 patients with coronary artery stenosis greater than 50% were selected as the CHD group and 1,540 adults with coronary artery stenosis less than 50% were selected as the non-CHD group. The clinical data, including HCT, were subjected to non-parametric tests and chi-square tests. The relationship between HCT and CHD was statistically analyzed using logistic regression. Wall shear stress (WSS) is obtained through fluent software combined with Navier-Stokes (NS) equation calculation.

Results: Multivariate logistic regression analysis showed that HCT was an independent risk factor for CHD [risk ratio (RR) 1.108, 95% confidence interval (CI): 1.084-1.133, P<0.001]. The area under the receiver operating characteristic (ROC) curve for the ability of HCT to predict CHD events was 0.726. The cut-off value was 44.13, with specificity of 0.701 and sensitivity of 0.702. The results of a computational fluid dynamics simulation demonstrated that the magnitude of HCT is positively correlated with the WSS. When HCT exceeds 50%, the WSS of the stenosis site reaches 42 Pa, which may lead to endothelial denudation and further damage to the blood vessel, resulting in plaque rupture.

Conclusions: HCT is one of the risk factors for CHD. Combining HCT with traditional risk factors may be helpful for non-invasive diagnosis of CHD. In addition, the level of HCT may also help to judge the future prognosis of patients with coronary artery stenosis greater than 50% without revascularization, providing a new potential target for future clinical treatment of CHD.