“No Reflow After Primary Percutaneous Intervention–IVUS Assessment and Predictive Factors”

Background Persistent no reflow is a common and serious complication after primary percutaneous coronary intervention (PCI) for ST‐elevation myocardial infarction (STEMI). The extent to which intravascular ultrasound (IVUS) assessment of plaque and thrombus characteristics can predict this complication has not been widely reported in the literature. Objectives To identify qualitative and quantitative parameters of atherosclerotic plaque on IVUS that predict no reflow in patients undergoing primary PCI. Materials & Methods We analysed the STEMI subset from our previously reported study of patients with acute coronary syndromes (ACS) undergoing PCI. Clinical, angiographic and imaging characteristics of patients who developed no reflow after primary PCI for STEMI were analysed and compared with those of patients who achieved normal blood flow after PCI. Results IVUS‐guided primary PCI was performed in 105 patients (107 lesions) who presented with STEMI between October 2021 and August 2022. The mean age was 58.1 ± 10.9 years. The incidence of no reflow was 12/105 (11.43%). Preprocedural TIMI 0 flow in the infarct‐related artery (IRA) was an important predictor of no reflow (66.7% vs 28.4%, p = 0.014). Plaque attenuation length was longer (11.47 mm vs 4.93 mm, p = 0.043), and a mean attenuation length of ≥ 6.67 mm predicted no reflow with a sensitivity of 80% and specificity of 63.6%. Thrombus characteristics were not predictive of final flow in the IRA. Conclusions Patients with preprocedural TIMI 0 flow in the infarct‐related artery and a long length of attenuated plaque on IVUS have a higher risk of no reflow after primary PCI.