Clinical Impact of Suboptimal Stenting and Residual Intrastent Plaque/Thrombus Protrusion in Patients With Acute Coronary Syndrome

Background— Clinical consequences of optical coherence tomographic (OCT) high-definition visualization of plaque/stent structures in acute patients remain undefined. In this retrospective substudy, we assessed the prognostic impact of postprocedural culprit lesion OCT findings in patients with acute coronary syndrome undergoing percutaneous coronary intervention. Methods and Results— In the CLI-OPCI (Centro per la Lotta Contro L’Infarto-Optimization of Percutaneous Coronary Intervention) database collecting cases from 5 independent OCT-experienced centers, we retrospectively analyzed postprocedural OCT findings in acute coronary syndrome patients and explored its possible impact (specifically that of residual intrastent plaque/thrombus protrusion) on outcome. From 2009 to 2013, 507 patients (588 lesions) were evaluated. Patients experiencing device-oriented cardiovascular events showed more frequently the features of suboptimal stent implantation defined as the presence of significant residual intrastent plaque/thrombus protrusion (hazard ratio [HR], 2.35; P <0.01), in-stent minimum lumen area (MLA) <4.5 mm 2 (HR, 2.72; P <0.01), dissection >200 µm at distal stent edge (HR, 3.84; P <0.01), and reference lumen area <4.5 mm 2 at either distal (HR, 6.07; P <0.001) or proximal (HR, 8.50; P <0.001) stent edges. Postprocedural OCT assessment of treated culprit lesion revealed at least one of these parameters in 55.2% of cases, with an associated increased risk of device-oriented cardiovascular events during follow-up (17.9% versus 4.8%; P <0.001). Both the presence of at least one of these parameters (HR, 3.69; P =0.002) and the residual intrastent plaque/thrombus protrusion (HR, 2.83; P =0.008) were confirmed as independent predictors of device-oriented cardiovascular events. Conclusions— In this retrospective study of acute coronary syndrome patients undergoing percutaneous coronary intervention, a composite of OCT-defined suboptimal stent implantation characteristics at the culprit lesion and residual intrastent plaque/thrombus protrusion was associated with adverse outcome.