The group of inventions is directed to improving the reliability and objectivity of assessment of the risk of cardiovascular complications. Using optical capillaroscopy of the nail fold of a finger in a state of reactive hyperemia and in the absence thereof, the size of the perivascular area and the diameters of the venous and arterial portions of the capillaries are measured, pulse wave velocity and the level of endothelial function in the upper limb are measured simultaneously relative to the R peak of an electrocardiogram, and an index K of the risk of cardiovascular complications is calculated using the given expression and categorized. The device comprises: a pneumatic means for creating occlusion in a limb of the patient and pressure sensors connected to occlusion cuffs an input unit capable of receiving and regulating the level of signals from the output of the pressure sensors and of amplifying and pre-filtering said signals an optical capillaroscopy unit capable of measuring the size of the perivascular zone and the diameters of the venous and arterial portions of the nail fold capillaries of a finger in a state of reactive hyperemia and in the absence thereof an electrocardiogram recording unit capable of generating a pulsed synchronization signal based on the R wave of the electrocardiogram a unit for amplitude-to-digital conversion, digital signal processing and control, a switching unit, and a unit for communicating with a computer.
