CURRENT OASIS 7 (Clopidogrel Optimal Loading Dose Usage to Reduce Recurrent Events/Optimal Antiplatelet Strategy for Interventions) Commentary

Abstract

Background: CURRENT OASIS 7 (Clopidogrel Optimal Loading Dose Usage to Reduce Recurrent Events/Optimal Antiplatelet Strategy for Interventions) is a multicentre international randomized third phase clinical trial which involved patients from 39 countries and was conducted by investigators from Population Health Research Institute at McMaster University.

Aim: The aim of the study was to establish optimal antiplatelet treatment in patients with acute coronary syndromes (ACS) scheduled to undergo early (within 24 hours of hospital admission) coronary angiography with eventual angioplasty – comparison was made of double-dose clopidogrel and high-dose aspirin treatment with standard-dose treatment and their influence on cardiovascular prognosis and incidence of bleeding.

Methods: The study involved 25087 patients (27,4% female, mean age 61,4 years). The primary composite endpoint consisted of cardiovascular death, myocardial infarction and stroke at 30 days.

Results: 24 739 (99%) patients underwent coronarography and 17 232 (70%) - angioplasty. Only patients who underwent coronary angioplasty benefited significantly from administration of high-dose clopidogrel - primary composite endpoint at 30 days occurred in 4,5% of patients on the standard-dose compared to 3,9% of patients on the high dose of clopidogrel (HR=0,85; p=0,036), what is synonymous with 13% reduction of its incidence. In the group of patients who underwent angioplasty and were treated with double doses of clopidogrel major bleeding incidence was significantly higher (1,6% v. 1,1%, HR=1,44; p=0,006), but no increase in intracerebral (0,046% v. 0,035%; HR=1,35; p=0,69) or fatal bleeding (0,07% v. 0,15%; HR=0,47; p=0,125) was noted. No significant difference in efficacy or bleeding incidence between groups treated with standard and high doses of aspirin was found.

Conclusions: Double-dose clopidogrel regimen decreases incidence of stent thrombosis and major cardiovascular events in ACS patients undergoing angioplasty with only slight increase in major bleeding. No difference in efficacy or bleeding between groups treated with standard and high-dose aspirin was found.