Macrophage infiltrates in coronary plaque erosion and cardiovascular outcome in patients with acute coronary syndrome

Background and aims Plaque erosion (PE) is responsible for at least one-third of acute coronary syndrome (ACS), and inflammation plays a key role in plaque instability. We assessed the presence of optical coherence tomography (OCT)-defined macrophage infiltrates (MOI) at the culprit site in ACS patients with PE, evaluating their clinical and OCT correlates, along with their prognostic value. Methods ACS patients undergoing OCT imaging and presenting PE as culprit lesion were retrospectively selected. Presence of MOI at culprit site was assessed. The incidence of major adverse cardiac events (MACEs), defined as the composite of cardiac death, recurrent myocardial infarction and target-vessel revascularization (TVR), was assessed [follow-up median (interquartile range, IQR) time 2.5 (2.03–2.58) years]. Results We included 153 patients [median age (IQR) 64 (53–75) years, 99 (64.7%) males]. Fifty-one (33.3%) patients presented PE with MOI and 102 (66.7%) PE without MOI. Patients having PE with MOI compared with PE patients without MOI had more vulnerable plaque features both at culprit site and at non-culprit segments. MACEs were significantly more frequent in PE with MOI patients compared with PE without MOI [11 (21.6%) vs. 6 (5.9%), p = 0.008], mainly driven by a higher risk of cardiac death and TVR. At multivariable Cox regression, PE with MOI was an independent predictor of MACEs [HR = 2.95, 95% CI (1.09–8.02), p = 0.034]. Conclusions Our study demonstrates that among ACS patients with PE the presence of MOI at culprit lesion is associated with more vulnerable plaque features, along with a worse prognosis at a long-term follow-up.