Blood viscosity changes in slow coronary flow patients

Abstract

Microvascular dysfunction is implicated in the pathogenesis of slow coronary flow (SCF), but less attention has been paid to intrinsic properties of blood that can also impair the microcirculatory flow. In this study we aimed to evaluate the blood viscosity focusing on erythrocyte aggregation, erythrocyte deformability and plasma viscosity in SCF. Thirty-three patients with SCF (21 male, 54 ± 12.8 years) and 23 subjects with normal coronary arteries (13 male, 59 ± 10.3 years) were included in the study. Coronary flow was quantified by means of thrombolysis in myocardial infarction (TIMI) frame count and aggregation and deformability of erythrocytes were measured by an ektacytometer. Plasma viscosity was measured by a cone-plate viscometer. Aggregation amplitude (23 ± 3.8 au vs. 15.7 ± 6.1 au, respectively, p < 0.001) and area A index (area above syllectogram) (153.2 ± 30.7 au.s vs. 124.9 ± 49.3 au.s, respectively, p < 0.01) were higher in SCF patients. Aggregation half-time, aggregation index, elongation index and plasma viscosity values were similar between two groups. Correlation analysis revealed a significant relationship between the TIMI frame count for left anterior descending artery and aggregation amplitude in SCF patients (r = 0.679, p < 0.0001). The result of this study reveals changes in erythrocyte aggregation which may contribute to the pathophysiology of SCF. Larger studies are needed to make more robust conclusions on this issue.

Endothelial function and hemorheological parameters modulate coronary blood flow in patients without significant coronary artery disease

“…Previous studies have shown an increased viscosity in patients with coronary slow flow at angiography [8], and the existence of a strong correlation between blood viscosity and MPV [28]. In our dataset, hematocrit was strongly associated with TIMIfc and was independent of endothelial function and platelet parameters across a wide range of TIMIfc.…”

“…Further, blood samples were processed immediately after collection in order to limit the impact of storing on hemorheological parameters. Finally, the role of platelet, erythrocyte and leukocyte aggregability has been previously demonstrated [8,13] and was not studied here.…”

Effects of synthetic colloid and crystalloid solutions on hemorheology in vitro and in hemorrhagic shock

“…The aggregation amplitude may be more sensitive than the aggregation index. It has been indicated that the aggregation amplitude is significantly higher in patients with slow coronary flow, whereas there was no significant difference between the groups with respect to the aggregation index [ 30 ]. In another study, Hazer et al demonstrated the effect of pravastatin on hemorheological parameters in a rodent traumatic brain injury model.…”

The association between coronary slow flow and platelet distribution width among patients with stable angina pectoris

“…Hb concentration is a determinant of blood viscosity, and a significant relationship between CSF and Hb concentration has been demonstrated previously [ 11 ]. The SCF patients frequently present with elevated blood viscosity [ 23 ]. Similar to atherosclerosis, blood viscosity is elevated in SCF patients as a result of increased platelet adhesion to the subendothelium, elevated protein infiltration into the arterial wall, and alterations to local shear forces [ 24 ].…”