Aims: To test whether a non-stenting anti-thrombotic strategy was still effective at 4-year follow-up in patients enrolled in the EROSION study and to explore potential predictors of long-term prognosis.
Methods and results: Out of 55 patients who completed 1-month follow-up, 52 patients finished 4-year follow-up. The median duration was 4.8 years (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 1 patient had gastrointestinal bleeding, and 11 patients underwent elective target lesion revascularization (TLR). Patients in the non-TLR group had more optical coherence tomography (OCT) thrombus reduction from baseline to 1 month; 95% patients in the non-TLR group versus 45% in the TLR group (p=0.001) met the primary endpoint (thrombus volume reduction >50%). Consistent with the OCT findings, angiographic results showed that the TLR group had less improvement in diameter stenosis (p=0.014) at 1 month compared with non-TLR group.
Conclusions: Four-year follow-up findings reconfirmed the safety of an anti-thrombotic therapy without stenting for erosion-caused acute coronary syndrome. Patients with better response to anti-thrombotic therapy in the first month were less likely to require stent implantation during the next four years.