Percutaneous coronary intervention

Percutaneous coronary intervention (PCI) is a non-surgical procedure used to treat narrowing (stenosis) of the coronary arteries of the heart found in coronary artery disease. After accessing the blood stream through the femoral or radial artery, the procedure uses coronary catheterization to visualise the blood vessels on X-ray imaging. After this, an interventional cardiologist can perform a coronary angioplasty, using a balloon catheter in which a deflated balloon is advanced into the obstructed artery and inflated to relieve the narrowing; certain devices such as stents can be deployed to keep the blood vessel open. Various other procedures can also be performed. Percutaneous coronary intervention (PCI) is a non-surgical procedure used to treat narrowing (stenosis) of the coronary arteries of the heart found in coronary artery disease. After accessing the blood stream through the femoral or radial artery, the procedure uses coronary catheterization to visualise the blood vessels on X-ray imaging. After this, an interventional cardiologist can perform a coronary angioplasty, using a balloon catheter in which a deflated balloon is advanced into the obstructed artery and inflated to relieve the narrowing; certain devices such as stents can be deployed to keep the blood vessel open. Various other procedures can also be performed. Primary PCI is the urgent use of PCI in people with acute myocardial infarction (heart attack), especially where there is evidence of heart damage on the electrocardiogram (ST elevation MI). PCI is also used in people after other forms of myocardial infarction or unstable angina where there is a high risk of further events. Finally, PCI may be used in people with stable angina pectoris, particularly if the symptoms are difficult to control with medication. PCI is an alternative to coronary artery bypass grafting (CABG, often referred to as 'bypass surgery'), which bypasses stenotic arteries by grafting vessels from elsewhere in the body. Under certain circumstances (extensive blockages, background of diabetes), CABG may be superior. Coronary angioplasty was first introduced in 1977 by Andreas Gruentzig in Switzerland. PCI is used primarily to open a blocked coronary artery and restore arterial blood flow to heart tissue, without requiring open-heart surgery. In patients with a restricted or blocked coronary artery, PCI may be the best option to re-establish blood flow as well as prevent angina (chest pain), myocardial infarctions (heart attacks) and death. Today, PCI usually includes the insertion of stents, such as bare-metal stents, drug-eluting stents, and fully resorbable vascular scaffolds (or naturally dissolving stents). The use of stents has been shown to be important during the first three months after PCI; after that the artery can remain open on its own. This is the premise for developing bioresorbable stents that naturally dissolve after they are no longer needed. The appropriateness of PCI use depends on many factors. PCI may be appropriate for patients with stable coronary artery disease if they meet certain criteria, such as having any coronary stenosis greater than 50 percent or having angina symptoms that are unresponsive to medical therapy. Although PCI may not provide any greater help in preventing death or myocardial infarction over oral medication for patients with stable coronary artery disease, it likely provides better relief of angina. In patients with acute coronary syndromes, PCI may be appropriate; guidelines and best practices are constantly evolving. In patients with severe blockages, such as ST-segment elevation myocardial infarction (STEMI), PCI can be critical to survival as it reduces deaths, myocardial infarctions and angina compared with medication. For patients with either non-ST-segment elevation myocardial infarction (nSTEMI) or unstable angina, treatment with medication and/or PCI depends on a patient's risk assessment. The door-to-balloon time is used as a quality measure for hospitals to determine the timeliness of primary PCI. The use of PCI in addition to anti-angina medication in stable angina  may reduce the number of patients with angina attacks for up to 3 years following the therapy, but does not reduce the risk of death, future myocardial infarction or need for other interventions. Coronary angioplasty is widely practiced and has a number of risks; however, major procedural complications are uncommon. Coronary angioplasty is usually performed using invasive catheter-based procedures by an interventional cardiologist, a medical doctor with special training in the treatment of the heart. The patient is usually awake during angioplasty, and chest discomfort may be experienced during the procedure. The patient remains awake in order to monitor the patient's symptoms. If symptoms indicate the procedure is causing ischemia the cardiologist may alter or abort part of the procedure. Bleeding from the insertion point in the groin (femoral artery) or wrist (radial artery) is common, in part due to the use of antiplatelet drugs. Some bruising is therefore to be expected, but occasionally a hematoma may form. This may delay hospital discharge as flow from the artery into the hematoma may continue (pseudoaneurysm) which requires surgical repair. Infection at the skin puncture site is rare and dissection (tearing) of the access blood vessel is uncommon. Allergic reaction to the contrast dye used is possible, but has been reduced with the newer agents. Deterioration of kidney function can occur in patients with pre-existing kidney disease, but kidney failure requiring dialysis is rare. Vascular access complications are less common and less serious when the procedure is performed via the radial artery.