Zero-contrast percutaneous coronary intervention for chronic total occlusions guided by intravascular ultrasound with ChromaFlo mode: a case report

BACKGROUND: Contrast agent allergy may result in severe adverse events that prevent the use of percutaneous coronary intervention (PCI) in some patients, especially for those with complex lesions. CASE SUMMARY: We describe a 59-year-old man who presented with the multi-vessel disease and suffered from contrast allergy. The patient refused to have coronary artery bypass grafting surgery, thus two-stage PCI procedures without iodinated contrast media were performed after a detailed discussion with the heart team, including a chronic total occlusion (CTO) lesion in the proximal left anterior descending artery. The intravascular ultrasound (IVUS) was used for finding the entry point of the proximal fibre cap, and assessing the lesion, thereby marking the positions of the proximal and distal edges of the stent. After PCI, stent expansion and subtle edge dissection or incomplete apposition were confirmed by IVUS and ChromaFlo imaging. Zero-contrast PCI was done successfully without any complication. DISCUSSION: This case report illustrates the feasibility and safety of performing CTO-PCI without contrast agent in carefully and well prepared selected patients.