The safety of ticagrelor monotherapy after primary percutaneous coronary intervention for ST-elevation myocardial infarction and the effect on intramyocardial haemorrhage

De-escalation of dual antiplatelet therapy (DAPT) to P2Y12inhibitor monotherapy
after 1-3 months of DAPT has shown to reduce bleeding complications without an
increase in thromboembolic complications when compared to standard DAPT in
patients undergoing percutaneous coronary intervention (PCI). These results
have been confirmed in patients with ST elevation myocardial infarction
(STEMI). As most bleeding events occur in the first month after PCI, direct
omission of aspirin after PCI could further reduce bleeding complications. Next
to a reduction in clinical bleeding outcomes, ticagrelor monotherapy compared
to DAPT may reduce the incidence and expansion of intramyocardial haemorrhage
(IMH), a frequent complication after revascularisation in STEMI patients which
leads to an increased infarct size and a worse prognosis. We designed this
pilot trial to assess the safety regarding thromboembolic events of ticagrelor
monotherapy directly after primary PCI (PPCI) in patients with STEMI and
investigate whether ticagrelor monotherapy versus DAPT leads to a reduction of
IMH. For this secondary endpoint we will only include an anterior STEMI
subgroup, as anterior STEMI is associated with a higher incidence of IMH. We
hypothesize that ticagrelor monotherapy compared to DAPT after PPCI for STEMI
is safe regarding thromboembolic complications and reduces IMH and infarct
size.

This study has been transitioned to CTIS with ID 2024-517783-37-00 check the CTIS register for the current data.

The main objective is to assess the safety and feasibility of the direct
omission of aspirin after PPCI with the continuation of ticagrelor monotherapy
in STEMI patients.
The secondary objectives are to demonstrate the reduction of IMH and infarct
size in patients receiving ticagrelor monotherapy compared to DAPT, and to
compare bleeding outcomes of ticagrelor monotherapy versus DAPT directly after
PPCI for STEMI.

This is an open-label, prospective multicentre randomized clinical trial (RCT)
in STEMI patients undergoing PCI.

Patients in the treatment arm will continue with ticagrelor monotherapy after
PPCI. The control arm will receive ticagrelor based DAPT for 12 months.

The safety of ticagrelor monotherapy after 1-3 months of dual antiplatelet
therapy has been demonstrated in multiple large RCT*s of which two sub studies
of the STEMI population confirm these results in STEMI patients. Furthermore,
two pilot studies of which one included patients with NSTEMI and one patients
with stable coronary artery disease, suggest that it is safe to discontinue
aspirin directly after PPCI and continue treatment with a potent P2Y12
inhibitor such as prasugrel or ticagrelor.
However, the safety of ticagrelor monotherapy directly after PPCI has not yet
been investigated. Therefore, we designed this pilot study with a relative
small number of participants to assess the safety which will be monitored by a
DSMB. We reduced the ischemic risk by excluding patients with suboptimal stent
result and patients that undergo PCI for stent thrombosis. Furthermore,
venagraft stenting is excluded as this is also associated with increased risk
of stent thrombosis.
We think that patients/participants will benefit from this new treatment as we
hypothesize that this treatment is safe and will reduce clinical bleeding
complications and intra myocardial hemorrhage, improving prognosis after PCI.