Optical Coherence Tomography‐Defined Vulnerable Plaques and Intracoronary Thrombus in Acute Coronary Syndromes: Insights From the OPTICO‐ACS Program

Background We investigated the prognostic significance of angiographic thrombus burden in acute coronary syndromes and explored underlying plaque vulnerability features using optical coherence tomography (OCT). Methods The prospective, multicenter OPTICO‐ACS (Optical‐Coherence Tomography in Acute Coronary Syndrome) study included 300 patients with acute coronary syndromes undergoing percutaneous coronary intervention. Angiographic thrombus burden (TB) was classified as high (HTB) and low, and optical coherence tomography was used to assess underlying culprit lesion morphology. Plaque vulnerability was defined by >2 features among thin‐cap fibroatheroma, large lipid arc (>180°), microcalcifications, and macrophage infiltration. The primary outcome was major adverse cardiac events, defined as cardiac death, nonfatal myocardial infarction, stroke, target vessel revascularization, or revascularization for angina. Secondary outcomes comprised individual components of the primary composite outcome and all‐cause mortality. Results Patients with HTB displayed a higher prevalence of plaque vulnerability than those with low TB (89.0% versus 75.3%; P =0.002). Vulnerable plaques were independently associated with HTB (adjusted odds ratio, 2.5 [95% CI, 1.31–4.89]; P =0.005). At a median follow‐up of 12 months, patients with HTB had a significantly higher incidence of short‐term (12.3% versus 1.4%; P <0.001) and long‐term (22.1% versus 13.7%; P =0.04) major adverse cardiac events. In multivariable Cox regression, HTB was identified as an independent predictor of long‐term major adverse cardiac events (adjusted hazard ratio, 2.2 [95% CI, 1.23–3.98]; P =0.008), whereas underlying plaque vulnerability did not. Conclusions In acute coronary syndromes, culprit plaques with vulnerable morphology were associated with larger intracoronary thrombus, which was associated with adverse clinical outcomes after percutaneous coronary intervention. TB may represent the active and prognostically relevant expression of plaque vulnerability, bridging morphological instability and clinical outcomes. Registration URL: https://clinicaltrials.gov/study/NCT03129503 .