PCI and clopidogrel: antiplatelet responsiveness and patient characteristics

• Published in: Acta cardiologica Vol. 66; no. 3; p. 333
• Main Authors: Grdinic, Aleksandra, Vojvodic, Danilo, Djukanovic, Nina, Colic, Mirko, Grdinic, Aleksandar G, Ignjatovic, Vladimir, Majstorovic, Ivana, Ilic, Vesna, Magic, Zvonko, Obradovic, Slobodan, Ostojic, Miodrag, Dolijanovic, Slavica Pavlov
• Format: Journal Article
• Language: English
• Published: England 01.06.2011
• Subjects: Adult; Aged; Angioplasty, Balloon, Coronary; Cell Adhesion Molecules - analysis; Drug Resistance; Drug Therapy, Combination; Female; Humans; Male; Microfilament Proteins - analysis; Middle Aged; Myocardial Infarction - prevention & control; Phosphoproteins - analysis; Pilot Projects; Platelet Aggregation - drug effects; Platelet Aggregation Inhibitors - administration & dosage; Platelet Aggregation Inhibitors - pharmacology; Platelet Aggregation Inhibitors - therapeutic use; Platelet Count; Prospective Studies; Thrombosis - prevention & control; Ticlopidine - administration & dosage; Ticlopidine - analogs & derivatives; Ticlopidine - pharmacology; Ticlopidine - therapeutic use
• ISSN: 0001-5385
• DOI: 10.2143/AC.66.3.2114133

This study on responsiveness to clopidogrel and aspirin evaluates its interaction with: (i) patient characteristics; (ii) procedure characteristics; (iii) antiplatelet dose. After elective PCI, 60 patients receiving aspirin 100 mg daily, and clopidogrel 75 mg daily were monitored with the PFA 100 test and VASP assay. Non-responsiveness to aspirin and clopidogrel was found in 23 (38%) and 18 (30%) of 60 patients, respectively. Seven (12%) patients were dual nonresponders. Non-responders to both aspirin and clopidogrel were more often smokers. Non-responders to clopidogrel, in addition had elevated inflammatory markers (P < 0.05). Dual non-responders had (i) a higher platelet count, LDL, and CRP; (ii) a lower HDL (P < 0.05). Clopidogrel non-responders were receiving 150 mg clopidogrel, with a positive response in 72%. Eighty % of non-responders to 150 mg clopidogrel were also non-responders to aspirin. Baseline patient characteristics and clopidogrel dose modify the antiplatelet response. Also, patients resistant to both aspirin and clopidogrel do no benefit from an increased clopidogrel dose.