Abstract 16601: Dual Antiplatelet Therapy Resistance to Aspirin and Clopidogrel Identifies Patients at the Highest Risk of Recurrent Atherothrombotic Events After Percutaneous Coronary Intervention
Background: High on-clopidogrel platelet reactivity (HCPR) and high on-aspirin platelet reactivity (HAPR) are associated with atherothrombotic events following coronary stenting. However, there are few data concerning high on-treatment platelet reactivity to aspirin and clopidogrel simultaneously. The aim of the present study is to determine the incidence of dual antiplatelet therapy resistance (DAPR) and its impact on clinical outcome.
Methods: On-treatment platelet reactivity was measured in parallel by light transmittance aggregometry (LTA) (n=921) and the VerifyNow®-System (n=422) in 951 patients on dual antiplatelet therapy undergoing elective stent-implantation. HCPR and HAPR were established by receiver operator characteristic curve analysis. The primary endpoint was a composite of all-cause death, non-fatal acute myocardial infarction, stent thrombosis and ischemic stroke at one-year follow-up.
Results: The incidence of DAPR varied between 14.7% and 26.9% according to the platelet function test used. DAPR as assessed by the VerifyNow®-System (Area Under Curve (AUC)=0.80) and LTA (AUC=0.75) was highly associated with adverse clinical outcome. Using LTA, patients exhibiting isolated HCPR (11.7%), isolated HAPR (9.6%) or DAPR (10.7%) had similarly increased risk for the primary endpoint as compared to patients without HPR (4.2%, all p-values <0.01). At one-year follow-up the primary endpoint occurred more frequently in patients with DAPR as compared to patients without HPR (17.7% vs. 4.1%, p = 0.001) when platelet function was evaluated with the VerifyNow®-System.
Conclusions: Dual antiplatelet therapy resistance identifies a patient population at the highest risk for atherothrombotic events in patients undergoing elective PCI with stent implantation. Dual antiplatelet therapy resistance as measured by the VerifyNow®-System has the highest predictability of atherothrombotic events.
- © 2010 by American Heart Association, Inc.