Interventional cardiology: the future beyond the coronaries

It was not long ago that I was a medical student at McGill. I graduated in the class of 1996. When I started to do interventional work as a Cardiology Resident at McGill, we were well into the era of coronary intervention. Almost every balloon angioplasty was followed by the implantation of a stent, which had been shown to improve the immediate and long-term results of interventional therapy. Life was becoming easier, dual antiplatelet therapy had emerged and replaced heparin, dextran, and warfarin which were initially used to treat every patient with a stent to prevent acute thrombosis. Our equipment had improved with better, less bulky balloons that allowed for smaller caliber guiding catheters and arterial access. This allowed vascular complications to diminish significantly. Stents were now being manufactured attached to balloon catheters decreasing the risk of stent embolization. There were also a number of pharmacologic strategies including 2B3A inhibitors which significantly reduced morbidity in high risk patients. It has been about 8 years since I first scrubbed for an angioplasty and much has changed. We now know quite a bit about patient selection, risk management, and the outcomes after coronary interventions. Regular stents are still widely in use but drug eluting stents are being implanted in great numbers. The albatross around the neck of the stent era of coronary intervention was in-stent restenosis, an aggressive healing response to the arterial injury which occurs with both balloon angioplasty and stent implantation. This process results in renarrowing of the stented segment over the course of the first 6 to 9 months of follow up. Restenosis generally presents as recurrent angina. The risk of restenosis is related primarily to the presence of diabetes, and the length and diameter of the stent implanted. The arrival of drug eluting stents has greatly diminished the risk of patients developing restenosis and thereby requiring repeat procedures and suffering recurrent symptoms. Drug eluting stents have encouraged a more aggressive percutaneous approach to the treatment of coronary artery disease in patients who would have previously been directed toward surgical revasculariztion. When only bare metal stents were available, it was hard to justify pursuing an angioplasty that would almost certainly result in restensosis. Drug eluting stents have been implicated in an increased risk of stent thrombosis (a much more deadly acute occlusion of a stented segment) late after the index procedure. Drugs are likely to delay endothelialization of the …