Percutaneous coronary intervention, or PCI, is a technique used to restore and maintain an adequate blood supply to the muscle of the heart. Cardiac muscle is supplied by what are known as coronary arteries, which can become narrowed or obstructed in certain conditions. During percutaneous coronary intervention, a surgical balloon is inflated inside a narrowed artery, widening it and improving blood flow. A tube called a stent is left in place in the newly widened section in order to keep it open. Percutaneous coronary intervention may also be referred to as balloon angioplasty, or coronary angioplasty.
Indications for percutaneous coronary intervention include some types of heart attack and some forms of angina. Angina is a condition where the coronary arteries, which supply heart muscle, fail to provide enough blood for the heart to function normally. This typically causes chest pain to be experienced during exercise. For people whose angina is only mild, PCI may not be necessary, and the condition may be controlled with drugs. In some cases, coronary artery bypass surgery may be more suitable, where a blood vessel from elsewhere in the body is used to bypass a blocked artery.
During percutaneous coronary intervention, the patient is awake but sedated. Fluoroscopy, a technology that provides moving X-ray images, is used to monitor the procedure. A wire is inserted into an artery in the arm or leg and moved up into the narrowed coronary artery. This wire is then used to guide the balloon into position.
Inflation of the balloon serves to widen the artery at its narrow point, and, if the stent was originally slipped over the deflated balloon, it is simultaneously expanded into place. In other cases, the stent is positioned after the balloon has been withdrawn. Sometimes, what is known as a cutting balloon may be used, with blades that score the fatty plaques on the walls of a narrowed artery. This allows the thickened area to break up and stretch more freely, and the balloon may be inflated to a lower pressure yet still widen the artery sufficiently.
Following percutaneous coronary intervention, most patients experience an improvement in their condition. In cases where coronary arteries were completely blocked, the outlook is less certain, with a successful outcome in only around half of cases. Even when percutaneous coronary intervention has a positive result, it is possible for complications to arise later. Occasionally, blood clots may form inside the stent, and it is usually necessary to take aspirin and other drugs to prevent blood clotting or strokes following PCI. Sometimes, healing of the artery wall around the stent may occur to such an extent that it causes narrowing again, requiring a repeat of the original procedure.