P2Y12i monotherapy reduces risk of myocardial infarction compared to aspirin monotherapy
Monotherapy with a P2Y12 inhibitor or aspirin for secondary prevention in patients with established atherosclerosis: a systematic review and meta-analysis
Introduction and methods
Treatment with an antiplatelet agent is recommended for secondary prevention in patients with established cerebrovascular, coronary, or peripheral artery disease [1-4]. Treatment with aspirin has a proven net benefit in secondary cardiovascular prevention . P2Y12 inhibitors provide an alternative to aspirin and pharmacodynamic studies have shown that P2Y12 inhibitors provide more profound platelet inhibition compared to aspirin [6,7]. In this study, a systematic review and meta-analysis were performed to evaluate the effect of P2Y12 inhibitor monotherapy vs aspirin monotherapy on clinical outcomes in patients with cerebrovascular, coronary, or peripheral artery disease.
A total of nine randomized trials were included in this study, in which 42108 patients were randomly allocated to a P2Y12 inhibitor (n=21043) or aspirin (n=21065). The co-primary endpoints were myocardial infarction (MI) and stroke. Key secondary endpoints included all-cause death and vascular death. Secondary safety endpoints were any bleeding and major bleeding.
- Patients who received a P2Y12 inhibitor had a lower risk of MI, compared to patients who received aspirin (OR 0.81, 95%CI 0.66-0.99, I²=10.9%). The number needed to treat with P2Y12 inhibitors to prevent one MI was 244 patients.
- There were no differences between those who received a P2Y12 inhibitor and those who received aspirin in terms of risk of stroke (OR 0.93, 95%CI 0.82-1.06, I²=24.5%), all cause death (OR 0.98, 95%CI 0.89-1.08, I²=0%), and vascular death (OR 0.97, 95%CI 0.86-1.09, I²=0%).
- No difference between treatment with a P2Y12 inhibitor and aspirin was observed in terms of risk of any bleeding (OR 1.08, 95%CI 0.91-1.29, I²=51.3%), and major bleeding (OR 0.90, 95%CI 0.74-1.10, I²=3.9%). Patients who received a P2Y12 inhibitor had a lower risk of gastrointestinal bleeding, compared to those who received aspirin (OR 0.59, 95%CI 0.39-0.89, I²=18.2%).
- Ischemic outcomes by type of P2Y12 inhibitor (ticlopidine, clopidogrel or ticagrelor) showed findings consistent with the primary analysis. A stratified analysis according to qualifying disease were also consistent with the primary analysis.
Patients who received P2Y12 inhibitor monotherapy had a lower risk of MI, compared to patients who received aspirin. No differences in risk of stroke, all cause death and vascular death were found between those who received a P2Y12 inhibitor and those who received aspirin. The clinical relevance of the benefit of P2Y12 inhibitor is debatable due to the high number needed to treat to prevent one MI and the absence of an effect on all-cause and vascular mortality.