Clopidogrel vs aspirin in patients with established cardiovascular disease: Systematic review and meta-analysis
Key Takeaway
This systematic review and meta-analysis of 05 RCTs* compared clopidogrel monotherapy with aspirin monotherapy in patients with established CVD.
Clopidogrel monotherapy vs aspirin monotherapy was associated with:
- 17% relative risk reduction for nonfatal MI (P = 0.02).
- Marginally decreased risk for MACE (P = 0.05).
- Similar risks for ACM, ischemic stroke, and major bleeding events.
Clopidogrel monotherapy provides better or at least similar benefits in patients with established CVD vs aspirin monotherapy.
Overall, study findings might contribute toward future clinical practice recommendations for the choice of antiplatelet drugs in patients with established CVD.
Why this Matters
Aspirin is recommended for secondary prevention of CVD, while clopidogrel is only used in cases of aspirin resistance.
- The RCTs comparing aspirin and clopidogrel have reported heterogeneous results.
This systematic review compared clopidogrel monotherapy vs aspirin monotherapy to provide the best currently available evidence† in patients with established CVD.
Study Design
This systematic review and meta-analysis (CRD42021283866) was performed by applying
PICO strategy to define search question.
Studies Included
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Peer-reviewed RCTs
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Articles published in English
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Articles comparing aspirin with clopidogrel monotherapies
Studies Excluded
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Studies in non-English language
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Observational studies
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Studies on aspirin + dipyridamole combinations
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Meta-analyses
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Systematic reviews
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Editorials
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Letters to the editor
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Case series or case reports
Intervention Arm: Clopidogrel monotherapy.
Comparator Arm: Aspirin monotherapy.
Endpoints Assessed
- Primary Outcome: ACM.
- Secondary Outcomes: IS, nonfatal MI, MACE‡ and major bleeding events.
Key Results
Overall, 05 RCTs (26,855 adult patients) were eligible for the analysis.
Baseline Characteristics | ||
---|---|---|
Clopidogrel Arm | Aspirin Arm | |
Mean Age | 62.7 years | |
Mean Follow-up | 19.9 months | |
Number of Patients | 13,426 | 13,429 |
Females (n) | 3,473 | 3,470 |
Outcomes
Outcome | Studies reported (Total number of patients) | Patients in clopidogrel arm | Patients in aspirin arm | OR (95% CI) | P-value | I2 |
---|---|---|---|---|---|---|
Primary Outcome |
||||||
ACM | 5 (26,855) | 717 | 708 | 1.01 (0.91–1.13) | 0.83 | 0.00% |
Secondary Outcomes |
||||||
IS | 4 (26,671) | 546 | 0.87 (0.71–1.06) | 0.87 (0.71–1.06) | 0.16 | 11.13% |
Nonfatal MI* | 5 (26,855) | 305 | 367 | 0.83 (0.71–0.97) | 0.02 | 0.00% |
MACE | 5 (26,855) | 1,330 | 1,267 | 0.84 (0.71–1.00) | 0.05 | 36.49% |
Major bleeding events | 4 (26,667) | 181 | 223 | 0.77 (0.56–1.06) | 0.11 | 34.77% |
*RRR: 16.9%; ARR: 0.5%; NNT: 217 for a mean period of 20 months |
Cumulative study results compared with individual studies
- Results were consistent for mortality, stroke and major bleeding events
- No difference found for nonfatal MI
- Results from individual studies varied considerably for nonfatal MI for MACE
For information on sensitivity analysis, please click on the hyperlink.
Key Limitations
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The included studies had great heterogeneity.
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Aspirin dose varied between studies, which might have confounded study results.
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All included studies were conducted in different countries, so populations studied may differ in terms of treatment response
For additional details, please refer the source publication Tasoudis PT, et al.
* Studies included in the analysis: Cadet, Watch, ASCET, Caprie and Host-Exam
† In Terms of efficacy and safety
‡ Defined differently between the studies.
Abbreviations
ACM; all-cause-mortality; ARR, absolute risk reduction; CI, confidence interval; CVD, cardiovascular disease; I2, heterogeneity; IS, ischemic stroke; MACE, major adverse cardiovascular events; MI, myocardial infraction; NNT, number needed to treat; OR, odds ratio; PICO, patient intervention control outcome; RCT, randomized controlled trial; RRR, relative risk reduction.
Reference
- Tasoudis PT, Kyriakoulis IG, Sagris D, Diener HC, and Ntaios G. Clopidogrel monotherapy versus aspirin monotherapy in patients with established cardiovascular disease: Systematic review and meta-analysis. Thromb Haemost. 2022;122(11):1879-1887. doi: 10.1055/a-1853-2952. PMID: 35577054.