Key Points:
- In the ARISE-ARMYDA 7 trial, 40 patients who presented with ST elevation myocardial infarction and a plan for a deferred stenting strategy were randomized to receive rivaroxaban 2.5 mg + dual-antiplatelet therapy (DAPT) or DAPT alone to evaluate the primary endpoint of OCT-derived thrombus burden reduction after six days.
- There was a significantly greater reduction in OCT-derived thrombus burden after 6 days in the rivaroxaban + DAPT group compared to the DAPT alone group.
Although percutaneous coronary intervention (PCI) is the preferred treatment for an ST-elevation myocardial infarction, PCI can be challenging in cases with large thrombotic burden in which there is a high risk for distal thrombus embolization. In the ARISE-ARMYDA 7, patients who presented with STEMI and a large thrombotic burden with a plan for a delayed stenting strategy were randomized to receive rivaroxaban 2.5 mg + dual-antiplatelet therapy (DAPT) including aspirin and ticagrelor or DAPT alone to evaluate the primary endpoint of OCT-derived thrombus burden reduction after six days.
To be included in the trial, patients had to have presented with a STEMI with symptom onset within 24 hours and a plan for a deferred stenting strategy. Patients also had to have a large thrombus burden, culprit vessel ≥ 3.0 mm, and successful thrombus aspiration of balloon angioplasty restoring ≥ TIMI 2 flow. Enrolled patients were planned to undergo OCT assessment of their thrombus score at baseline and again at 5-7 days.
The study enrolled 44 patients of which 40 underwent follow-up OCT imaging. The mean patient age was 62 years old and 12.5% of patients were female. The authors found a significantly greater reduction in thrombus burden in the rivaroxaban + DAPT group compared to the DAPT alone group with a difference in thrombus score of 66 vs 44 respectively (p=0.040). There were also reductions in two secondary endpoints – thrombus volume and thrombus area—in the treatment group. Although the study was not powered for clinical endpoints, there were no major adverse cardiac events in the treatment group and only 2 minor bleeding events.
There are several important limitations of this study. First, patients with high bleeding risk were excluded from the sample and only patients who were going to receive a delayed stenting strategy were eligible for inclusion. This represents a small, focused subset of patients within the STEMI population. In addition, because the focus was on an OCT-based primary outcome instead of clinical outcomes, it is unclear what the clinical impact of treatment with rivaroxaban 2.5 mg + DAPT would be. Finally, the small sample size further limits the generalizability of the study. In conclusion, although the treatment strategy of rivaroxaban 2.5 mg + dual-antiplatelet therapy led to a reduction in OCT-based thrombus burden at 6 days among patients with STEMI undergoing a delayed stenting strategy, the findings of this study may not be generalizable and it would be important for future studies to evaluate clinical endpoints in a larger population.