Residual inflammatory risk after acute coronary syndromes (ACSs) remains a critical contributor to atherosclerosis progression and plaque destabilization. Inflammatory biomarkers such as interleukin-1 receptor antagonist (IL-1ra), resistin, and C-reactive protein (CRP) may provide additional insights into coronary lesion complexity and vulnerability. The main aim of the study was to evaluate the association of interleukin-1 receptor antagonist (IL-1ra), resistin, and C-reactive protein (CRP) with coronary disease extent; functional significance of non-culprit lesions, assessed by fractional flow reserve (FFR); and plaque vulnerability, assessed by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS). This prospective study enrolled 93 ACS patients undergoing invasive coronary assessment for an ACS. Inflammatory biomarkers were measured at admission and 6 months post-event. Patients were stratified post hoc into tertiles by biomarker distribution. SYNTAX score, FFR, and OCT-defined thin-cap fibroatheroma (TCFA) were used to characterize lesion burden and morphology. Multivariate logistic regression was performed adjusting for conventional cardiovascular risk factors and ACS type. Higher tertiles of IL-1ra, resistin, and CRP were significantly associated with increased SYNTAX score (p < 0.05), FFR < 0.80 (68% in the highest tertile), and presence of TCFA (62% vs. 20%, p < 0.01). All biomarkers correlated with coronary disease severity. In multivariate logistic models, IL-1ra (OR 1.23 per 100 pg/mL, p = 0.03), resistin (OR 2.35 per 1 ng/mL, p = 0.001), and CRP (OR 1.11 per 0.001 ng/mL, p = 0.006) independently predicted high-risk coronary profiles. IL-1ra, resistin, and CRP are independently associated with lesion complexity, functional significance, and vulnerability in ACS. Inflammatory biomarker profiling may provide complementary anatomical and physiological assessment in future ACS risk stratification strategies.

Background/Objective: Percutaneous coronary intervention (PCI) has a pivotal role in the treatment of coronary artery disease (CAD). Although PCI is generally guided only angiographically, advancements in intravascular imaging, particularly in optical coherence tomography (OCT), may offer significant advantages. OCT provides high-resolution cross-sectional images that allow for a more detailed assessment of lesion characteristics and procedural outcomes, which are not fully available with angiography. These findings are associated with or predictive of major adverse cardiovascular events (MACE), encouraging the use of OCT in PCI procedures. This study sought to characterize the role of post-PCI OCT imaging in PCI optimization in patients with CAD. Methods: This retrospective study includes patients who underwent OCT-guided PCI. A total of 64 patients with various types of CAD were included. The primary endpoint was the identification of suboptimal stent implantation as evaluated with OCT after stent implantation, and the secondary endpoint was the assessment of the possibility to achieve optimal stent implantation after further OCT-guided optimization based on standard definitions of optimal PCI. Results: In total, 73 vessels were studied, 42.46% (31) had a stent expansion index (SEI) of < 80%, 31.51% (23) had an SEI between 80–90%, and 26.03% (19) had an SEI of more than 90%. Minimum stent area (MSA) of more than 4.5 mm² was found in 82.19% (60) of vessels, while 17.80% (13) had an MSA below the cut-off value. Suboptimal stent implantation was identified in 35.61% (26) of vessels, including underexpansion 9.58% (7), malapposition 15.06% (11), stent edge dissection 6.85% (5), plaque burden or lipid-rich pool in the stent edges 2.73% (2), and tissue protrusion 1.36% (1). Post-PCI OCT optimization resulted in significant improvements, with only 6.84% (5) of the vessels still not achieving all OCT criteria for optimal stent implantation. Conclusions: In patients with CAD, post-PCI OCT evaluation provided useful information, otherwise unavailable by angiography alone. We identified that 35.61% (26) of the targeted vessels, were suboptimally stented. OCT imaging was able to provide procedural and strategic guidance for optimization until the appropriate results, based on our criteria, were achieved in most of the lesions.