The role of whole blood viscosity in premature coronary artery disease in women

Abstract

Background: Impaired hemorheology has been demonstrated in atherosclerotic disease and has shown a relationship with classical risk factors. Blood viscosity ( η), being the ratio of shear stress over shear rate, is an important parameter of hemorheology. In women with premature coronary artery disease (CAD), the underlying risk factors are a matter of debate and the role of whole blood viscosity in its pathogenesis has not been documented. Aim: To investigate the association of whole blood viscosity with premature CAD in women, with complaints suggestive of angina pectoris. Methods: Eighty-eight women (mean age 53 years) were divided into two groups, those with a high likelihood of CAD (LIKELI+) and those with a low likelihood of CAD (LIKELI−), based on medical history and technical investigations. Assessment of risk factors comprised smoking, diabetes mellitus, arterial hypertension, left ventricular hypertrophy (LVH), systolic and diastolic blood pressures, total low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, triglycerides, body mass index, menopause, hormone replacement therapy, uric acid and creatinine, and predicted 10-year cardiovascular risk according to the Framingham study was calculated. Whole blood viscosity was determined at 37 °C using a rotational cone-and-plate viscosimeter. Results: Baseline characteristics did not differ significantly between the groups except for antiplatelet therapy ( P=0.001), prevalence of diabetes mellitus ( P=0.002), predicted 10-year cardiovascular risk ( P=0.007), essential hypertension ( P=0.02), LVH ( P=0.03) and smoking habits ( P=0.04). LIKELI+ women had a significantly higher whole blood viscosity at all shear rates compared with LIKELI− women ( P<0.05). All blood viscosities measured from 25 to 125 s −1 were highly significantly ( P<0.0001) correlated with η 250 s −1 . Univariate correlates with η 250 s −1 comprised triglycerides ( P=0.006) and haematocrit ( P=0.026). Binary logistic multivariate regression analysis for high likelihood of CAD revealed that only presence of arterial hypertension ( P<0.0001) was predictive. Multiple regression analysis demonstrated that haematocrit ( P=0.001) and likelihood of CAD ( P=0.01) were the only significant determinants of η 250 s −1 . Conclusion: In this study, blood viscosity did not appear as an independent risk factor for the prediction of premature CAD in women. Viscosity may act as a marker of CAD or of classical risk factors.