Abstract 20979: Is Age an Independent Predictor of Residual Platelet Reactivity in Patients Undergoing Elective Percutaneous Coronary Intervention?
Objectives: Ageeing associates with prognosis in patients undergoing elective percutaneous coronary intervention (PCI). Though, it still remains unclear whether residual platelet reactivity (RPR) and periprocedural myocardial infarction (MI) are higher in elderly after oral administration of high reloading doses of clopidogrel and aspirin.
Methods: Five hundred forty six consecutive patients (n=347, age: ≥65 years and n=199, age<65 years), on maintenance daily doses of 75 mg of clopidogrel and 100 mg of aspirin, scheduled for elective PCI were prospectively recruited. All patients received high reloading doses of clopidogrel (600 mg) and aspirin (500 mg) 12–24 hours before PCI. Blood was collected before and 24 hours after PCI to determine: a) RPR using the point-of-care assay VerifyKnow and b) Troponin T, as a marker of MI. MI was defined as an increase in troponin greater than 3 × 99th percentile of the upper reference limit.
Results: Elderly patients had higher RPR, as expressed by higher P2Y12 reaction units (PRU) (236±92 vs 208±87 in non-elderly, p=0.001). By multivariate analysis, age was an independent predictor of PRU [beta: 2.1, p<0.001, 95% Confidence interval (CI):1.2–3.1] and aspirin reaction units (beta: 0.9, p=0.012, 95% CI:0.2–1.6). An age of 71 years was identified as the best cut-off value of age to predict suboptimal response to clopidogrel (PRU≥240)(sensitivity: 68%, specificity: 47%, area under the curve: 0.59). When deciles of age were taken into account, higher rates of periprocedural MI were observed in the higher (age≥80) as compared to the lower deciles (age<54, p=0.04) (figure). None of the patients presented TIMI major bleeding.
Conclusions: Residual platelet reactivity is higher in elderly patients undergoing elective PCI despite the administration of high reloading doses of clopidogrel and aspirin.
- © 2010 by American Heart Association, Inc.