The EROSION study (Effective Anti-Thrombotic Therapy Without Stenting: Intravascular Optical Coherence Tomography–Based Management in Plaque Erosion) allowed us to observe the healing process of coronary plaque erosion in vivo. The present study aimed to investigate the incidence of newly formed healed plaque and different baseline characteristics of acute coronary syndrome (ACS) patients caused by plaque erosion with or without newly formed healed plaque using optical coherence tomography (OCT).

A total of 137 ACS patients with culprit plaque erosion who underwent pre-intervention OCT imaging and received no stent implantation were enrolled. Patients were stratified according to the presence or absence of newly formed healed phenotype at 1-month (137 patients) or 1-year OCT follow-up (52 patients). Patient's baseline clinical, angiographic, OCT characteristics and outcomes were compared.

There were 55.5% (76/137) of patients developed healed plaque at 1 month, and 69.2% (36/52) of patients developed healed plaque at 1 year. Patients with newly formed healed plaque had larger thrombus burden, and lower degree of area stenosis (AS%) at baseline than those without, and thrombus burden and AS% were predictors of plaque healing. The healing process was accompanied by the significant increase of AS% and incidence of microchannels, and greater inflammatory response. The outcomes appeared to be similar between the two groups.

Newly formed healed plaque was found in more than half of ACS patients with plaque erosion without stenting. Patients with newly formed healed plaque had lower luminal stenosis and larger thrombus burden. During healing process, luminal stenosis increased gradually.