COMMIT-CCS 2
COMMIT-CCS 2: Clopidogrel and Metoprolol in Myocardial Infarction Trial-Second Chinese Cardiac Study

# Overview
The cardioprotective effects of aspirin in patients with acute myocardial infarction (MI) have been well established. However, whether the routine administration of the ADP inhibitor clopidogrel (Plavix, Sanofi-Aventis and Bristol-Myers Squibb) together with aspirin adds further protection has not been assessed in a randomized, controlled study.

# Study Design
The Clopidogrel and Metoprolol in Myocardial Infarction Trial-Second Chinese Cardiac Study (COMMIT-CCS 2) is the largest clinical study ever conducted in China; it enrolled 45,852 patients at 1250 centers in China. COMMIT-CCS 2 was a randomized, parallel controlled trial that used a 2 x 2 factorial design to assess the effects of adding 75 mg of clopidogrel (vs. placebo) and the effects of adding the beta blocker, metoprolol (vs. placebo) in acute MI patients on aspirin therapy (162 mg daily).
Patients with suspected AMI (ST change or new left bundle branch block) within 24 hours of symptom onset were enrolled in the study; patients undergoing primary PCI or those with a high risk of bleeding were excluded.
Primary endpoint: Death and the composite of death, reinfarction, and stroke up to 4 weeks in hospital or prior to discharge.
Mean treatment duration and follow-up was 16 days.

# Results
A total of 22,960 patients were randomized to clopidogrel 75 mg daily and 22,891 patients were randomized to placebo; all patients were treated with aspirin. Baseline characteristics were well balanced between study groups. In each group, 26% of patients were older than 70 years of age, 34% were randomized within 6 hours of symptom onset, and fibrinolytic therapy was administered in 50% of patients, including 68% of ST segment elevation MI patients presenting within 12 hours. Other concomitant drug therapies were well used, and prescribing patterns among Chinese physicians matched those used in Western countries.
ACE = angiotensin converting enzyme; LBBB = left bundle branch block; STEMI = ST elevation myocardial infarction
The incidence of the study's primary composite endpoint (death, reinfarction, stroke) was significantly lower in the clopidogrel arm than in the control arm (10.1% vs 9.3%, 2P =0.002). This significant difference translated into a 9% reduction in the relative risk of the composite endpoint.
A total of 1728 (7.7%) in-hospital deaths were reported in the clopidogrel group vs 1846 (8.1%) in-hospital deaths in the control group, accounting for a 7% relative risk reduction (2p=0.03).
Clopidogrel was also found to reduce the risk of reinfarction by 13% relative to placebo (2p=0.02) and reduced the risk of all strokes by 14%, but the difference did not reach statistical significance, which was mostly attributable to a reduced incidence of ischemic stroke. In addition, there was no difference in the rate of major bleeding events between the 2 groups.
The treatment effect of clopidogrel on the primary endpoint occurred relatively quickly, with a 10% reduction in favor of clopidogrel within 12 hours, and with each additional day, there was further benefit.
The risk reduction in the primary endpoint with clopidogrel vs placebo remained consistent across all prespecified subgroups, including those treated and not treated with lytic therapy. There was a slight trend suggesting that greater benefit was achieved when the study drug was administered within 6 hours.

# Conclusions
- Adding 75 mg of clopidogrel daily in acute myocardial infarction patients prevents approximately 10 major vascular events per 1000 treated patients.
- There was no excess of cerebral, fatal, or transfused bleeds.
- Each million  patients treated for approximately 2 weeks would avoid 5000 deaths and 5000 nonfatal deaths.

# Reference
- AHA Scientific Sessions 2005
- COMMIT CCS2 Website

# Additional and up-to-dated Information about all Cardiovascular Trials
- Clinical Trial Results