Percutaneous coronary intervention (PCI) is a minimally invasive procedure used to treat coronary artery disease, a condition where plaque builds up in the arteries that supply blood to the heart. During PCI, a catheter is inserted into a blood vessel and guided to the blocked or narrowed coronary artery. A small balloon on the end of the catheter is inflated to open up the artery and improve blood flow to the heart. In some cases, a stent may be placed to help keep the artery propped open. PCI is a common and effective treatment for coronary artery disease and can help reduce symptoms such as chest pain and improve overall heart function.