Atomic Force Microscopy as a Tool to Evaluate the Risk of Cardiovascular Diseases in Patients

Abstract

High fibrinogen levels are a relevant cardiovascular risk factor, but the biological mechanisms associated with pathologic alterations are not totally clear. Fibrinogen-erythrocyte binding in chronic heart failure (CHF) patients and its prognostic value were evaluated.15 ischemic and 15 non-ischemic CHF patients, as well as 15 healthy donors were enrolled in the study. Fibrinogen-erythrocyte interactions were evaluated, at the single-molecule level, by atomic force microscopy (AFM)-based force spectroscopy. Clinical outcome was assessed during a 12-months follow-up. AFM stiffness studies were also performed on erythrocytes from these patients and compared with the control.Force spectroscopy data showed that CHF patients presented higher fibrinogen-erythrocyte binding forces than the control group, despite a lower binding frequency. According to etiology, ischemic patients had higher binding forces than donors and lower binding frequency. Ischemic patients presented increased fibrinogen-erythrocyte binding forces relative to non-ischemic. Non-ischemic patients also had a lower binding frequency than donors. Increased cell stiffness (or decreased elasticity) was determined for both groups of CHF patients, with the larger variation being observed for the non-ischemic patients. Clinical follow-up data demonstrated that patients presenting higher fibrinogen-erythrocyte binding forces at the beginning of the study had a higher probability of being hospitalized due to cardiovascular complications on the subsequent year.As fibrinogen-erythrocyte interactions, evaluated by AFM, are modified in CHF patients and associated with short-term clinical outcome, here we demonstrate the power of this biophysical evaluation as potential biomarker for cardiovascular risk and patients’ clinical prognosis evaluation [Guedes et al. (2016) Nature Nanotechnol., doi:10.1038/nnano.2016].