Potent P2Y₁₂ Inhibitor Monotherapy vs DAPT After PCI in Patients With and Without STEMI: The NEO-MINDSET Substudy

The effects of very early aspirin withdrawal with potent P2Y₁₂ inhibitor monotherapy after percutaneous coronary intervention may differ based on acute coronary syndrome (ACS) presentation.

This prespecified analysis from the NEO-MINDSET trial evaluated whether treatment effects of early aspirin discontinuation differ between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation ACS (NSTE-ACS; defined as unstable angina or non-ST-segment elevation myocardial infarction).

NEO-MINDSET randomized ACS patients to potent P2Y₁₂ inhibitor monotherapy initiated within 4 days of hospitalization vs standard dual antiplatelet therapy (DAPT) with aspirin and a potent P2Y₁₂ inhibitor for 12 months. Co-primary outcomes were: 1) the composite of all-cause death, myocardial infarction, stroke, and urgent target vessel revascularization (ischemic outcome); and 2) Bleeding Academic Research Consortium types 2, 3, or 5 bleeding (bleeding outcome).

Of the 3,410 participants included, 2,119 (62.1%) presented with STEMI and 1,291 (37.9%) with NSTE-ACS. Among STEMI patients, an early aspirin-free strategy was associated with a higher rate of the co-primary ischemic composite outcome compared with DAPT at 1 year (8.2% vs 5.2%, respectively; HR: 1.60; 95% CI: 1.14-2.24), whereas among those with NSTE-ACS, ischemic event rates were similar between monotherapy and DAPT (5.1% vs 6.0%, respectively; HR: 0.84; 95% CI: 0.53-1.35; P for interaction = 0.030). The co-primary bleeding outcome was lower with monotherapy than with DAPT in both STEMI (HR: 0.37; 95% CI: 0.22-0.61) and NSTE-ACS (HR: 0.45; 95% CI: 0.23-0.86) populations (P for interaction = 0.650).

In patients with STEMI treated with percutaneous coronary intervention, early aspirin withdrawal may be harmful, because it increases the risk of ischemic events. Conversely, in NSTE-ACS, potent P2Y₁₂ inhibitor monotherapy may be a viable therapeutic option: Ischemic event rates were similar and bleeding was reduced compared with DAPT. (Percutaneous Coronary Intervention Followed by Antiplatelet Monotherapy in the Setting of Acute Coronary Syndromes [NEOMINDSET]; NCT04360720).