Predictors of non-stenting strategy for acute coronary syndrome caused by plaque erosion: four-year outcomes of the EROSION study

Background: The EROSION study demonstrated that patients with an acute coronary syndrome (ACS) caused by plaque erosion could be treated with antithrombotic therapy without stenting. However, the long-term prognosis of this strategy is still unclear.

Aims: The aim of this study was to test whether a non-stenting antithrombotic strategy was still effective at four-year follow-up and to explore potential predictors of long-term prognosis.

Methods: This study was a long-term follow-up of the EROSION study. Follow-up was conducted by phone call or clinical visit. Patients were divided into two groups – those with target lesion revascularisation (the TLR group), and the non-TLR group.

Results: Out of 55 patients who completed one-month follow-up, 52 patients finished four-year follow-up. The median duration was 4.8 years (range, 4.2-5.8 years). The majority of patients remained free from events, and all patients were free from hard endpoints (death, myocardial infarction, stroke, bypass surgery, or heart failure). Only one patient had gastrointestinal bleeding, and 11 patients underwent TLR. Patients in the non-TLR group had more optical coherence tomography (OCT) thrombus reduction from baseline to one month; 95% of patients in the non-TLR group versus 45% in the TLR group (p=0.001) met the primary endpoint (thrombus volume reduction >50%). Angiographic results showed that the TLR group had less improvement in diameter stenosis (p=0.014) at one month compared with the non-TLR group.

Conclusions: Four-year follow-up findings reconfirmed the safety of an antithrombotic therapy without stenting for ACS caused by erosion. Patients with better response to antithrombotic therapy in the first month were less likely to require stent implantation during the next four years.