Introduction

Percutaneous coronary intervention has become a more common procedure than coronary artery bypass surgery in many countries, and the number of procedures continues to rise. In one day an interventionist may treat four to six patients with complex, multivessel disease or acute coronary syndromes. Various balloons, stents, and other devices are delivered by means of a 2 mm diameter catheter introduced via a peripheral artery. The success rate is over 95%, and the risk of serious complications is low. After a few hours patients can be mobilised, and they are usually discharged the same or the next day. Even the spectre of restenosis is now fading.

Refinements of existing techniques

The present success of percutaneous procedures is largely because of refinement of our “basic tools” (intracoronary guidewires and low profile balloons), which have greatly contributed to the safety and effectiveness of procedures. However, the greatest technological advance has been in the development of stents. These are usually cut by laser from stainless steel tubes into a variety of designs, each with different radial strength and flexibility. They are chemically etched or electropolished to a fine finish and sometimes coated.

Digital angiography is a great advance over cine-based systems, and relatively benign contrast media have replaced the toxic media used in early angioplasty. Although magnetic resonance and computed tomographic imaging may become useful in the non-invasive diagnosis of coronary artery disease, angiography will remain indispensable to guide percutaneous interventions for the foreseeable future.

New device technology

Pre-eminent among new devices is the drug eluting (coated) stent, which acts as a drug delivery device to reduce restenosis. The first of these was the sirolimus coated Cypher stent. Sirolimus is one of several agents that have powerful antimitotic effects and inhibit new tissue growth inside the artery and stent. In a randomised controlled trial (RAVEL) …