Abstract 11369: Clopidogrel Up-Titration Versus Standard Dose in Patients with High Residual Platelet Reactivity After Percutaneous Coronary Intervention: A Single-Center Pilot Randomised Study
Aim This study was performed to evaluate the pharmacodynamic effect of clopidogrel up-titration versus the standard clopidogrel maintenance dose on platelet inhibition in patients with high residual platelet reactivity (HRPR) after percutaneous coronary intervention (PCI). Method and results Platelet reactivity (expressed as P2Y12 reaction units [PRU] by the point-of-care VerifyNow assay; Accumetrics, San Diego, CA) was tested 24 48 h after PCI in consecutive patients. All interventions were performed after pretreatment with 600 mg of clopidogrel. A cutoff value of 240 PRU was used to identify non-responders to clopidogrel treatment with HRPR. Patients with HRPR were then randomly assigned to Group A (clopidogrel up titration starting at 150 mg/day with further dose increases according to results of the VerifyNow test; attempt to reach a PRU value of < 240 up to day 30) or Group B (standard dose of 75 mg/day). VerifyNow P2Y12 testing was performed in 378 patients after PCI. Of these patients, HRPR was indentified in 134 (35%). Sixty patients were randomly assigned to Group A (n = 30, average age 65±11 years) and Group B (n = 30, average age 66±12 years). After intervention, the PRU value did not differ between the two groups (297±37 vs. 306±45, respectively; NS). Effective platelet inhibition (PRU < 240) at day 30 was observed in 26 (85%) patients in Group A and in 6 (20%) patients in Group B (p < 0.001). In 14 (46%) patients in Group A, a dose of clopidogrel higher than 150 mg was needed to achieve effective platelet inhibition. There was no difference in adverse events, including bleeding, during the 6-month follow-up. Conclusion Clopidogrel up-titration, based on VerifyNow P2Y12 testing, led to effective laboratory treatment. The clinical effects of this strategy should be assessed in larger randomised studies.
- © 2011 by American Heart Association, Inc.