Clopidogrel vs aspirin monotherapy following dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI): A systematic review and meta-analysis
This pooled analysis indicated that clopidogrel monotherapy was possibly more effective than aspirin monotherapy for secondary prevention in the post-PCI patient population without an increased risk of major bleeding.
Key Takeaway
- As per the authors, this is the first systematic review and meta-analysis till date comparing clopidogrel vs aspirin monotherapy exclusively in the post-PCI population after completion of DAPT. Noteworthy study findings included:
- Clopidogrel monotherapy was associated with a reduction in the endpoints of major adverse cardiac events (MACE), any stroke, ischemic stroke, and hemorrhagic stroke vs aspirin monotherapy
- No statistically significant differences were noted for the following outcomes in patients receiving clopidogrel vs aspirin monotherapy: Cardiac death, all-cause death, and major bleeding
- Following outcomes were comparable between both treatment groups: myocardial infarction (MI), repeat revascularization, target vessel revascularization (TVR), and stent thrombosis
Why This Matters
- Current guideline recommendations: At least 6 months of DAPT with aspirin + P2Y12 inhibitor for stable coronary artery disease; at least 12 months for acute coronary syndrome following PCI with drug-eluting stents (DES)
- Previous studies suggest a potential benefit of clopidogrel over aspirin for the secondary prevention of atherosclerotic cardiovascular disease, but these studies did not explore exclusively the post-PCI population.
- This study analyzed current evidence regarding efficacy/safety of clopidogrel vs aspirin specifically in post-PCI population after DAPT completion.
Study Design
- Systematic review and meta-analysis: Included five studies comparing clopidogrel with aspirin monotherapy following completion of DAPT post-PCI (randomized control trial [RCT] = 1; observational cohort study = 4)
- Inclusion criteria: (1) Any trials or observational studies that included adult patients (≥18 years); (2) studies comparing clopidogrel with aspirin following completion of DAPT for a minimum of 1 month after PCI
- Exclusion criteria: (1) Studies comparing aspirin with other types of P2Y12 inhibitors (e.g., ticagrelor, prasugrel) and different durations of DAPT post-PCI; (2) case reports, case series, editorials, systematic reviews, and narrative reviews; (3) abstracts without a full-text article
- Outcomes: MACE, cardiac death, all-cause death, MI, repeat revascularization, TVR, stent thrombosis, major bleeding, any stroke, ischemic stroke, and hemorrhagic stroke
Key Results
- Overall, 5 studies with 13,850 patients were included (40.4% patients received clopidogrel; 59.6% patients received aspirin; mean follow-up duration = 12–36 months; all patients received DES)
- In comparison to aspirin monotherapy, clopidogrel monotherapy was associated with a reduction in the below presented outcomes (with an absence of statistical heterogeneity [I2 = 0%]):
| Outcome | Clopidogrel | Aspirin | Relative Risk (RR [95% CI]) | P value |
| MACE | 3.6% | 4.2% | 0.77 (0.65–0.91) | 0.003 |
| Any stroke | 0.7% | 1.5% | 0.51 (0.35–0.76) | 0.0008 |
| Ischemic stroke | 0.4% | 0.7% | 0.55 (0.32–0.94) | 0.03 |
| Hemorrhagic stroke | 0.1% | 0.4% | 0.24 (0.09–0.68) | 0.007 |
- No significant differences were noted between the clopidogrel and aspirin groups in the following outcomes:
| Outcome | Clopidogrel | Aspirin | Relative Risk (RR [95% CI]) | P value | I2 |
| All-cause death | 1.8% | 1.9% | 1.06 (0.81–1.39) | 0.66 | 19% |
| Cardiac death | 0.9% | 1.2% | 0.87 (0.53–1.41) | 0.56 | 34% |
| Major bleeding | 0.8% | 1.1% | 0.74 (0.42–1.30) | 0.29 | 31% |
- As compared to aspirin monotherapy, clopidogrel monotherapy was not associated with a reduction in the following outcomes: MI, repeat vascularization, TVR, and stent thrombosis
Limitations
- Analysis used study-level data instead of individual patient-level data, and only available data was utilized (certain outcomes were not reported by all studies)
- Duration of DAPT post-PCI varied among studies which could potentially introduce clinical heterogeneity • Studies included were mainly observational in nature with only 1 RCT
- Studies included were mainly observational in nature with only 1 RCT
- All included studies had an East Asian population, which may limit the external validity of study findings
- Sensitivity analysis should be interpreted with caution (as small number of studies were included in this analysis)
*Please refer source publication (Tan et al.) for details on search strategy, study selection and data extraction, and outcome definitions (supplemental data).
Tan BE, Wong PY, Baibhav B, Thakkar S, Azhar AZ, Rao M, et al. Clopidogrel vs aspirin monotherapy following dual antiplatelet therapy after percutaneous coronary intervention: A systematic review and meta-analysis. Curr Probl Cardiol. 2022:101174. doi: 10.1016/j.cpcardiol.2022.101174. Epub ahead of print. PMID: 35341798.
MAT-BH-2300021/V1/JAN2023