Multiple electrode aggregometry and vasodilator stimulated phosphoprotein-phosphorylation assay in clinical routine for prediction of postprocedural major adverse cardiovascular events

• Published in: Thrombosis and haemostasis Vol. 106; no. 2; p. 230
• Main Authors: Freynhofer, Matthias K, Brozovic, Ivan, Bruno, Veronika, Farhan, Serdar, Vogel, Birgit, Jakl, Gabriele, Willheim, Martin, Hübl, Wolfgang, Wojta, Johann, Huber, Kurt
• Format: Journal Article
• Language: English
• Published: Germany 01.08.2011
• Subjects: Acute Coronary Syndrome - blood; Acute Coronary Syndrome - drug therapy; Acute Coronary Syndrome - therapy; Adult; Aged; Angioplasty, Balloon, Coronary - adverse effects; Cell Adhesion Molecules - blood; Drug Resistance; Female; Humans; Male; Microfilament Proteins - blood; Middle Aged; Phosphoproteins - blood; Phosphorylation; Platelet Aggregation - drug effects; Platelet Aggregation Inhibitors - adverse effects; Platelet Function Tests - methods; Predictive Value of Tests; Prospective Studies; Risk Factors; ROC Curve; Stents - adverse effects; Ticlopidine - adverse effects; Ticlopidine - analogs & derivatives
• ISSN: 0340-6245
• DOI: 10.1160/TH11-02-0077

Reduced antiplatelet effect of clopidogrel assessed with multiple electrode aggregometry (MEA) and vasodilator stimulated phosphoprotein-phosphorylation (VASP-P) assay has been proven to predict major adverse cardiovascular events (MACE) after coronary stenting. So far no consecutive registry has evaluated the usefulness of different adenosine diphosphate-based platelet function tests to predict outcome in unselected patients. Hence, our objective was to determine the feasibility of MEA and VASP-P for clinical routine and whether low-response to clopidogrel as determined by MEA and/or the VASP-P assays predicts MACE in a "real-life" population undergoing coronary stenting. Three-hundred consecutive patients were included in this prospective registry. Blood was sampled 6-24 hours after stenting to measure MEA and VASP-P. The use of glycoprotein-IIb/IIIa-blockers limited MEA to 196 measurements. Concerning the VASP-P assay, 300 measurements were achieved. Receiver Operating Characteristics (ROC)-curves of sensitivity and specificity estimates for MACE were plotted for VASP-P assay. The area under the ROC-curve was 0.683 (p=0.014) for the platelet reactivity index (PRI) calculated from median fluorescence intensities (FI) with an optimal cut-off at 60.2% PRI. Patients above 60.2% had a significantly increased risk for MACE at six months follow-up (p=0.007). Estimating the cut-offs for the PRI from mean FI (52%) or from geometric mean FI (56.6%) led to clinically relevant differences. VASP-P assay is feasible for clinical routine to measure clopidogrel effects and to predict post-procedural MACE in unselected patients. With regard to differing cut-offs, exact standardisation of the VASP-P assay is mandatory. The use of GP-IIb/IIIa-blockers prevents MEA testing and limits its usability in unselected patients.