Clopidogrel vs aspirin post PCI following DAPT

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).

MAT-BH-2300021/V1/JAN2023