1. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events
Purpose
To assess the relative efficacy of the antiplatelet drugs clopidogrel and aspirin in reducing the risk of thrombotic events in patients with atherosclerotic disease.
Reference
CAPRIE Steering Committee. A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). Lancet 1996;348:1329–39.

2. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - TRIAL DESIGN -
Multicenter, multinational, randomized, double-blind, parallel group
Patients
19,185 patients with atherosclerotic vascular disease (either recent ischemic stroke, recent MI or symptomatic peripheral arterial disease)
Follow up and primary endpoint
Primary combined endpoint: ischemic stroke, MI or vascular death. Mean 1.9 years follow up.
Treatment
Aspirin 325 mg once daily or clopidogrel 75 mg once daily

3. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - TRIAL DESIGN continued-
Patient subgroups
Aspirin
(n=9586)
Clopidogrel
(n=9599)
Stroke
33.4%
33.7% MI
32.9%
32.7%
Peripheral arterial disease
33.7%
33.6%
CAPRIE Steering Committee.
Lancet
1996;
348
:1329–39.

4. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - RESULTS -
Annual event rate for primary endpoint of ischemic stroke, MI or vascular death significantly reduced in clopidogrel group compared with aspirin (5.32 vs. 5.83%, p<0.043)
Effect of clopidogrel compared with aspirin indicated that benefit may not be identical between subgroups (p=0.042 for test of heterogeneity):
reduction in event rate was significant in patients with existing peripheral arterial disease
reduction in the group with previous stroke, though not significant
increased event rate in the group with previous MI, though not significant
Clopidogrel was well tolerated as defined by withdrawal rate from trial: only marginally higher vs aspirin (21.3 vs. 21.1%)

5. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - RESULTS continued -
Primary endpoint: stroke, MI or vascular death
Cumulative 20
risk (%) 15 10 5
Aspirin
Clopidogrel
p=0.043 6 12 18 24 30 36
Months after randomization
CAPRIE Steering Committee.
Lancet
1996;
348
:1329–39.

6. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - RESULTS continued -
Primary endpoint by subgroup
Subgroup
Treatment group
(patient years
at risk)
Events
per year
(%) p
Relative risk
reduction
(95% CI)
Relative risk reduction (%)
Aspirin
better
Clopidogrel
better
Stroke
Clopidogrel (6054)
7.15
7.3%
0.26
Aspirin (5979)
7.71
(–5.7 to 18.7) MI
Clopidogrel (5787)
5.03
–3.7%
0.66
Aspirin (5843)
4.84
(–22.1 to 12.0)
Peripheral
arterial
disease
Clopidogrel (5795)
3.71
23.8%
0.0028
Aspirin (5797)
4.86
(8.9 to 36.2)
All patients
Clopidogrel (17,636)
5.32
8.7%
0.043
Aspirin (17,519)
5.83
(0.3 to 16.5)
–30
–20
–10 10 20 30 40
CAPRIE Steering Committee.
Lancet
1996;
348
:1329–39.

7. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - RESULTS continued-
Stroke and MI
Aspirin
Clopidogrel
Patient years at risk
17,519
17,636
Stroke
Nonfatal
430
405
Fatal 32 33 MI
Nonfatal
270
226
Fatal 63 49
CAPRIE Steering Committee.
Lancet
1996;
348
:1329–39.

8. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - SUMMARY -
Compared with aspirin, in patients with atherosclerotic vascular disease, clopidogrel:
Reduced the primary combined endpoint of stroke, MI or vascular death in the total study population
Conferred benefit in peripheral arterial disease and stroke subgroups
Conferred no significant benefit in previous MI subgroup

9. CAPRIE: Clopidogrel versus Aspirin in Patients at risk of Ischemic Events - SUMMARY -
Compared with aspirin, in patients with atherosclerotic vascular disease, clopidogrel:
Reduced the primary combined endpoint of stroke, MI or vascular death in the total study population
Conferred benefit in peripheral arterial disease subgroup
Conferred no significant change in risk in stroke and MI subgroups