Abstract 13908: Tailored Antiplatelet Therapy to Improve Prognosis in Patients Exhibiting Clopidogrel Low-response Prior to Percutaneous Coronary Intervention
Aim: To investigate whether an intensified antiplatelet regimen could improve prognosis in stable or non-ST elevation acute coronary syndrome (ACS) patients exhibiting high on-treatment platelet reactivity (HTPR) on clopidogrel and treated with percutaneous coronary intervention (PCI).
Background: There is a wide variability in the platelet reactivity to clopidogrel and HTPR has been associated with a poor prognosis in terms of clinical outcome.
Methods: In this observational study, a total of 923 consecutive patients without ST-elevation myocardial infarction and adequately pre-treated with clopidogrel were screened for HTPR with multiple electrode aggregometry after assessment of the coronary anatomy. Patients were grouped based on whether they exhibited HTPR and on the assigned antiplatet treatment- either conventional clopidogrel treatment or intensified therapy. The primary endpoint was a composite of cardiovascular death, myocardial infarction, stroke, or stent thrombosis.
Results: HTPR was demonstrated in 237 patients (25.7%). Of these, 114 continued on conventional clopidogrel maintenance therapy (75 mg daily), while the remaining 123 received intensified antiplatelet therapy with either double-dose clopidogrel (150 mg daily, n=55) or the newer P2Y12-inhibitors, prasugrel or ticagrelor (n=68) for at least 30 days after the index procedure.
The median follow-up was 571 days (interquartile range, 373-746). Intensifying antiplatelet therapy reduced the rate of the composite cardiovascular events (p<0.001). After adjustment for potential confounders, HTPR in combination with conventional clopidogrel therapy remained independently associated with an increased risk of cardiovascular events (hazard ratio (HR), 2.92; 95% confidence interval (CI), 1.90-4.48), whereas intensified treatment reduced the risk to a level equivalent to that of patients exhibiting normal platelet reactivity (HR, 1.08; 95% CI, 0.59-1.99).
Conclusion: Tailored antiplatelet therapy with either the new generation of antiplatelet drugs or double maintenance-dose clopidogrel significantly reduced the event rate in patients exhibiting HTPR prior to PCI.
- © 2013 by American Heart Association, Inc.