Presentation on theme: "CARDIOLOGIA INV 1 CAREGGI - FIRENZE Objective To determine whether nonresponsiveness to clopidogrel as revealed by high in vitro residual platelet reactivity."— Presentation transcript:
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Objective To determine whether nonresponsiveness to clopidogrel as revealed by high in vitro residual platelet reactivity after a 600 mg loading of the drug is predictive of drug-eluting stent thrombosis and cardiac mortality at long-term follow-up
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Background The RECLOSE trial showed that nonresponsiveness to clopidogrel is predictive of drug-eluting stent (DES) thrombosis and cardiac mortality at 6 months. No data exist about the predictive value of long-term adverse events in patients with DES and clopidogrel loading non-responsiveness
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Methods (1) Methods (1) Consecutive pts receiving DES implantation and for whom platelet reactivity after clopidogrel loading was prospectively assessed. All pts were compliant to 6-month dual antiplatelet treatment. Blood samples for platelet reactivity assessment was obtained 12 to 18 hours from clopidogrel loading (600 mg). For patients receiving in the cath lab both the loading dose of clopidogrel and a IIb/IIIa inhibitor, blood samples were obtained after 6 days while patients were on 75 mg maintenance dose of clopidogrel.
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Platelet-rich plasma was stimulated with 10 M ADP and aggregation was assessed using LTA. Patients with platelet aggregation by 10 µmol ADP ≥ 90 th percentile of controls (70%) were defined as nonresponders. Methods (2)
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Primary end-point: stent thrombosis (ARC definitions) Definite Stent Thrombosis –Angiographic or pathologic confirmation AND at least ONE additional criteria: Acute ischemic symptomsAcute ischemic symptoms Ischemic ECG changesIschemic ECG changes Elevated cardiac biomarkersElevated cardiac biomarkers Probable Stent Thrombosis –Any unexplained death within 30 days of stent implantation –Any myocardial infarction in the territory of the implanted stent without angiographic confirmation of stent thrombosis Possible Stent Thrombosis –Any unexplained death beyond 30 days Secondary end-point: composite of cardiac mortality and stent thrombosis
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Time (days) 80 85 90 95 100 060120180240300360420480540600660720 Event-free survival % (definite or probable stent thrombosis) 97 ± 1 89 ± 3 Log rank p <.001 Responders Nonresponders LONG-TERM SURVIVAL FOR PRIMARY END-POINT n=803 pts; median time follow-up 639 days - IQ 555-756
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Incidence of cardiac mortality Cardiac mortality (overall) 11,4 % 2,7 % 3,8 % 1 % Cardiac mortality (after six months) nonrespondersresponders
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Timing of primary end-point (stent thrombosis) Events, n
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Incidence of stent thrombosis Stent thrombosis (overall) 11,4 % 2,6 % 2,8 % 0,3 % Stent thrombosis (after six months) nonrespondersresponders
CARDIOLOGIA INV 1 CAREGGI - FIRENZE Conclusions High residual platelet reactivity after 600 mg loading dose of clopidogrel, as revealed by a single assessment with LTA, is a strong predictor of cardiac death and DES thrombosis.