The Clopidogrel Aspirin Stent International Cooperative Study (CLASSICS) - CLASSICS


Double-Blinded Study of the Safety of Clopidogrel With and Without A Loading Dose in Combination With Aspirin Compared With Ticlopidine in Combination With Aspirin After Coronary Stenting: The Clopidogrel Aspirin Stent International Cooperative Study (CLASSICS)


To determine the relative safety of clopidogrel with and without a loading dose plus aspirin compared to ticlopidine plus aspirin in patients undergoing coronary stenting.

Study Design

Study Design:

Patients Enrolled: 1,020

Drug/Procedures Used:

1,020 patients who had undergone successful coronary stenting were randomized to receive for 28 days ticlopidine (250mg BID) plus aspirin (325 mg/d), clopidogrel (75 mg/d) plus aspirin (325 mg/d), or a loading dose of clopidogrel (300mg) followed by clopidogrel (75 mg/d) plus aspirin (325 mg/d). The primary endpoint was a composite of major peripheral or bleeding complications, neutropenia, thrombocytopenia or early discontinuation of the drug because of a non-cardiac event. The secondary endpoint included cardiovascular death, any MI and target vessel revascularization.

Principal Findings:

The primary endpoint occurred in 9.1% of patients in the ticlopidine group, 6.35% of patients in the 75 mg/d clopidogrel group, and in 2.9% of patients in the clopidogrel loading-dose group (4.6% incidence in the combined clopidogrel group, a 50% relative risk reductin when compared to ticlopidine, p<0.005). There were no significant differences among the three groups in the incidence of the secondary endpoints (respectively 0.9%, 1.5% and 1.2% of patients). There were only two deaths (one sudden and one associated with an MI), both occurring in the clopidogrel loading-dose group. MI rates were low: 0.58% in the ticlopidine group, 1.2% in the clopidogrel 75 mg/d group and 0.86% in the clopidogrel loading-dose group.

Clopidogrel appears to have superior safety and tolerability compared with ticlopidine and acceptable efficacy in the prevention of major adverse cardiac events following coronary stenting.


Although this study was not developed to determine efficacy, the results support the use of clopidogrel as an alternative to ticlopidine after coronary stenting.


1. Bertrand ME, Rupprecht HJ, Urban P, et al. Circulation 2000;102:624-29.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease

Keywords: Neutropenia, Risk, Coronary Artery Disease, Platelet Aggregation Inhibitors, Ticlopidine, Thrombocytopenia, Stents

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