Assessment of the Association Between Whole Blood Viscosity and Coronary Artery Calcium Score

<i>Background and Objectives</i>: Whole Blood Viscosity (WBV), estimated using the De Simone formula, is a key hemodynamic parameter linked to endothelial dysfunction and atherosclerosis. Its association with significant coronary calcification, defined as a high Coronary Artery Calcium Score (CACS ≥ 100), remains unclear. This study investigated whether calculated WBV predicts high CACS. <i>Materials and Methods</i>: In this single-center, retrospective, cross-sectional study, 403 patients undergoing coronary computed tomography angiography for suspected stable coronary artery disease were included. Participants were stratified into CACS < 100 (<i>n</i> = 258) and CACS ≥ 100 (<i>n</i> = 145). WBV was calculated at High Shear Rate (HSR) and Low Shear Rate (LSR) using the De Simone formula. Multivariate binomial logistic regression adjusted for conventional cardiovascular risk factors was used to identify independent predictors of high CACS. <i>Results</i>: Patients with CACS ≥ 100 were older, more frequently male, and had a higher prevalence of diabetes and hypertension (all <i>p</i> < 0.01). Mean WBV did not differ significantly between groups: WBV-HSR, 4.3 ± 0.5 cP vs. 4.4 ± 0.5 cP (<i>p</i> = 0.456); WBV-LSR, 29.9 ± 8.0 cP vs. 30.4 ± 8.6 cP (<i>p</i> = 0.505). In multivariate models, neither WBV-HSR (OR: 0.489; <i>p</i> = 0.462) nor WBV-LSR (OR: 0.987; <i>p</i> = 0.520) independently predicted high CACS. Age and sex were the strongest independent predictors (<i>p</i> < 0.001). <i>Conclusions</i>: No independent association was found between calculated WBV and high CACS in this cross-sectional study.