Use of biomedical photonics for in vivo and in vitro assessment of haemostasis and microcirculation in patients on antithrombotic therapy

Abstract

Abstract Background Antithrombotic therapy in patients with cardiovascular disease requires rapid translation of laboratory assessment of haemorrheological parameters in clinical cardiology practice. Both antiplatelet and anticoagulant agents, especially when used in combination, can potentially increase the risk of severe bleeding. The precise balance between thrombosis and hemorrhage is therefore pivotal to ensure optimal treatment results. Purpose To develop simple and reliable methods to control the haemorheological properties of the blood and to assess the risk of potential bleeding. Methods We assessed platelet aggregation parameters measured in vitro by laser aggregometry and optical trapping techniques in blood samples of 131 patients with coronary artery disease. Additionally, blood rheology and microcirculation parameters were assessed in vivo in the nail-fold area using the digital capillaroscopy system. Results We found a statistically significant correlation between the number of aggregated blood cells in vitro and the presence of aggregates in the blood capillaries in vivo. A significant correlation was also observed between red blood cells (RBC) aggregation time in vitro and capillary flow velocity in vivo. The most severe deterioration of the rheological properties was found in patients with diffuse atherosclerotic disease receiving combined antithrombotic therapy. Interestingly, optical examination of soft tissues surrounding the capillaries of the nail-fold area revealed the presence of micro-hemorrhages in patients with history of hemorrhagic complications on antithrombotic therapy (Fig. 1). Conclusion Novel methods of biomedical photonics applied for in vivo and in vitro assessment of the blood haemorrheological properties can provide important additional information on microcirculation parameters and optimize treatment in patients on antithrombotic therapy. Funding Acknowledgement Type of funding sources: None. In vivo nail-fold digital capillaroscopy