Methods for measuring platelet reactivity of patients that have received drug eluting stents

1 . A method of measuring platelet reactivity of a patient that has a drug-eluting stent (DES), comprising the steps of:

a) obtaining a blood sample from the patient;

b) creating a combination by mixing the blood sample with 1) an anticoagulant; 2) sufficient buffer to maintain the pH and salt concentration of the anticoagulated blood within a range suitable for platelet aggregation; 3) a platelet GPIIb/IIIa receptor ligand immobilized on a solid surface; 4) one or more agents to enhance a signal transduction pathway and 5) a receptor activator;

c) incubating the combination under conditions for agglutinating particles to form a mixture; and

d) assessing platelet-mediated agglutination in the mixture, wherein the absence of agglutination indicates that the patient has reduced ability to form platelet thrombi.

2 . A method for identifying a patient with a drug-eluting stent DES at risk for stent thrombosis, comprising the steps of:

a) obtaining a blood sample from the patient being assessed;

b) creating a combination by mixing the blood sample with 1) an anticoagulant; 2) sufficient buffer to maintain the pH and salt concentration of the anticoagulated blood within a range suitable for platelet aggregation; 3) a platelet GPIIb/IIIa receptor ligand immobilized on a solid surface; 4) one or more agents to enhance a signal transduction pathway and 5) a receptor activator;

c) incubating the combination under conditions for agglutinating particles to form a mixture; and

d) assessing platelet-mediated agglutination in the mixture, wherein the absence of agglutination in the mixture indicates that the patient has reduced ability to form platelet thrombi.

e) measuring platelet reactivity of the patient; and

f) determining a risk level of stent thrombosis of the patient in response to measurement of the platelet reactivity.

3 . A method for determining if a patient has clopidogrel-induced platelet inhibition, comprising the steps of:

a) obtaining a blood sample from the patient being assessed;

b) creating a combination by mixing the blood sample with 1) an anticoagulant; 2) sufficient buffer to maintain the pH and salt concentration of the anticoagulated blood within a range suitable for platelet aggregation; 3) a platelet GPIIb/IIIa receptor ligand immobilized on a solid surface; 4) one or more agents to enhance a signal transduction pathway and 5) a receptor activator;

c) incubating said combination under conditions for agglutinating particles to form a mixture; and

d) assessing platelet-mediated agglutination in the mixture, wherein the absence of agglutination indicates that the patient has reduced ability to form platelet thrombi.

e) measuring platelet reactivity of the patient; and

f) determining if the patient has clopidogrel-induced platelet inhibition in response to measuring platelet reacitivity.

4 . A method of measuring platelet reactivity of a patient that has a drug-eluting stent (DES), comprising the steps of:

providing an ADP platelet activator to a sample from the patient;

providing one or more platelet inhibitors to the sample, at least one of the platelet inhibitors being Prostaglandin E1 (PGE1);

actively producing an alternate signal transduction pathway in response to providing an ADP platelet activator and providing one or more platelet inhibitors,

wherein in response to activity producing an alternate signal transduction pathway with a final concentration of ADP being 2 to 35 μM and a final concentration of PGE1 is 2 to 30 nM; and

measuring platelet reactivity of the patient in response to the final concentration of the ADP.