Ticagrelor monotherapy versus dual antiplatelet therapy after primary percutaneous coronary intervention: one-year outcomes of the pilot STOP-IMH randomised trial

Abstract

Background: Ticagrelor monotherapy after a short period of dual antiplatelet therapy (DAPT) has been shown to be safe and effective after percutaneous coronary intervention (PCI), including primary PCI for patients with ST-segment elevation myocardial infarction (STEMI). However, the omission of aspirin could further reduce bleeding risk.

Aims: We aimed to assess the impact of ticagrelor monotherapy directly after primary PCI in terms of ischaemic events and to investigate the effect on clinical bleeding events.

Methods: In this multicentre, open-label pilot study, 200 STEMI patients were randomised 1:1 to ticagrelor monotherapy versus ticagrelor plus aspirin, directly after primary PCI. Major adverse cardiac and cerebrovascular events (MACCE) and bleeding were assessed at 13 months. The incidence of intramyocardial haemorrhage (IMH) was compared between groups.

Results: In the ticagrelor monotherapy group (n=98) and DAPT group (n=101), MACCE occurred in 4.1% versus 4.0%, respectively (hazard ratio [HR] 1.04, 95% confidence interval [CI]: 0.26-4.17). Clinically relevant bleeding was observed in 4.1% versus 10.9% (HR 0.37, 95% CI: 0.12-1.17), and clinically relevant non-access site bleeding in 2.0% versus 9.9% (HR 0.20, 95% CI: 0.04-0.92).

Conclusions: While no significant difference in ischaemic events was observed between ticagrelor monotherapy and DAPT in the first 13 months after primary PCI, this pilot study was underpowered to confirm efficacy. In addition, non-access site bleeding events were significantly reduced, and there was a downward trend in all clinical bleeding events. The incidence of IMH was similar between groups. (ClinicalTrials.gov: NCT05986968)