This is a case of a 79-year old man with severe aortic stenosis and recurrent GI bleeding. This case study by Schmid, et.al. proposes that Impact-R to determine platelet function may be more time- and cost-effective compared to electrophoretic analysis of vWF multimers.

Severe aortic stenosis with bleeding diathesis is also known as Heyde syndrome. The pathophysiology: loss of high molecular weight vWF multimers in high shear stress conditions leads to a platelet type von Willebrand disease (acquired vWD, vWD type 2B) which can explain the bleeding tendencies of a patient with severe aortic stenosis.

Along with other laboratory equipment, the Impact-R has been used in a study by Vaduqanathan, et.al. to evaluate platelet reactivity in patients with metabolic syndrome.

Metabolic syndrome is a combination of several medical conditions that increase the risk for developing cardiovascular disease and diabetes mellitus. It is also known as Syndrome X, insulin resistance syndrome, and Reaven’s syndrome.

The diagnostic criteria for metabolic syndrome (as defined by International Diabetes Foundation) includes central obesity with any two of the following:

–          Raised triglycerides

–          Reduced HDL cholesterol

–          Raised blood pressure

–          Raised fasting plasma glucose

Metabolic syndrome is associated with a prothrombotic state and platelet reactivity can therefore be considered a result. The study by Vaduqanathan, et.al. evaluated the platelet reactivity of patients with metabolic syndrome and their response to aspirin. They concluded that metabolic syndrome increases baseline platelet reactivity and lowers platelet response to aspirin.