Key takeaways

• Dual antiplatelet therapy with a potent P2Y12 receptor inhibitor plus aspirin is recommended for up to 12 months in patients receiving a stent after an ST-segment elevation myocardial infarction (STEMI).

• The PREMIUM trial compared a potent P2Y12 receptor inhibitor (prasugrel) without aspirin vs. a potent P2Y12 receptor inhibitor plus aspirin given at the time of percutaneous coronary intervention and for 12 months after.

• The results of the trial do not support upfront aspirin omission.

• Further studies are needed to determine the optimum antiplatelet regimen in patients after a STEMI.

Munich, Germany – 29 August 2026: Monotherapy using prasugrel failed to show noninferiority compared with potent antiplatelet therapy plus aspirin at the time of primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. This was the main finding of the PREMIUM trial presented in a Hot Line session today at ESC Congress 2026¹ and published simultaneously in the New England Journal of Medicine.

Antiplatelet therapy is crucial to managing the risk of subsequent cardiovascular events in patients with ST-segment elevation myocardial infarction (STEMI). Following percutaneous coronary intervention (PCI), ESC Guidelines generally recommend dual antiplatelet therapy (DAPT) consisting of a potent P2Y12 receptor inhibitor (prasugrel or ticagrelor) and aspirin for 12 months.² In specific clinical scenarios, the DAPT duration can be shortened.²

Principal Investigator, Doctor Gaku Nakazawa from Kindai University, Osaka, Japan, explained why the PREMIUM trial was carried out: “Previous randomised trials have demonstrated the safety of 1−3 months of DAPT followed by P2Y12 inhibitor monotherapy compared with 12 months of DAPT.2 However, the safety of initiating prasugrel as monotherapy at the time of contemporary imaging-guided PCI compared with standard 12-month DAPT remains unknown.”

The PREMIUM trial was an investigator-initiated, open-label, noninferiority trial conducted at 69 centres in Japan. Participants had a STEMI indicated for primary PCI with current generation platinum‑chromium everolimus-eluting stents. Patients with atrial fibrillation or other indications for oral anticoagulant therapy were excluded. Eligible patients were randomised (1:1) to either prasugrel monotherapy (20 mg loading, 3.75 mg daily) initiated before PCI or standard DAPT with aspirin plus prasugrel for 12 months. Patients at high bleeding risk in the DAPT group could receive DAPT for 3 months then prasugrel monotherapy at the clinician’s discretion. A total of 2,280 patients were randomised, with a mean age of around 69 years and 23% were women.

Noninferiority was not demonstrated for prasugrel monotherapy compared with DAPT for the primary endpoint of all-cause death, myocardial infarction or stroke at 12 months. The primary endpoint occurred in 11.0% of patients receiving prasugrel monotherapy and in 8.5% of patients in the DAPT group (hazard ratio [HR] 1.34; 95% confidence interval [CI] 1.02 to 1.75; p=0.40 for noninferiority).

As noninferiority was not met, the major secondary endpoint related to bleeding was not analysed statistically. Bleeding Academic Research Consortium type 3 or 5 bleeding occurred in 5.6% of patients in the prasugrel monotherapy group and 8.4% of patients in the DAPT group at 12 months (HR 0.66; 95% CI 0.47 to 0.91).

Stent-related complications (definite or probable stent thrombosis and clinically driven target lesion revascularisation) were similar between groups. In contrast, non-stent related events including non-target lesion revascularisation were more frequent with prasugrel monotherapy.

“These findings do not support prasugrel monotherapy at the time of primary PCI for STEMI,” concluded Doctor Nakazawa. “It appears that DAPT is needed for at least the first month but the optimum duration of DAPT remains to be determined.”

ENDS