Intravascular ultrasound (IVUS) is a special imaging tool used during heart procedures called percutaneous coronary intervention (PCI) to help doctors see inside blood vessels. This study compares results of heart stent procedures using IVUS guidance versus regular X-ray imaging, called angiography. The goal is to see if IVUS helps reduce heart problems and is cost-effective for high-risk patients. The study involves about 2,500-3,100 participants and takes place in the US, Canada, and Europe. It lasts approximately 4.5 years, with each participant followed for 2 years. Eligible participants are adults (18+ years) needing a heart stent for complex issues like blocked or narrowed arteries. Participants must not have had a recent heart attack or some other specific conditions.

• Study lasts about 4.5 years, with 2 years of follow-up for each participant.
• Involves heart stent placement using special imaging techniques.
• Participants are monitored to track outcomes and costs.