Guidewires are usually 0.014 in-thickness wires that are advanced across a lesion in the coronary artery and used as a rail to support the passage of devices. The guidewires are selected based on coronary anatomy and lesion morphology. Each guidewire must be flexible, steerable, as well as stiff enough to support advancing devices past the lesion. Guidewires are characterized by their coating, their stiffness, and tip load. When compared to hydrophobic wires, hydrophilic wires allow for easier passage across lesions but increase the risk of entering the subintimal space and small branches. An operator usually has a “workhorse” wire, which is a safe wire that is used routinely. A workhorse wire should be safe, durable, retain its tip shape, have 1:1 torquability, and offer moderate support for the delivery of devices. If the operator is unable to succeed using the workhorse wire, a different wire is used. The next choice of wire depends on the specific barrier to success with the workhorse. If more support is needed, upgrading to a wire with extra support such as a Choice Extra Support, Grand Slam or HT Iron Man is recommended. If there is difficulty in crossing the lesion, one may consider using a hydrophilic wire but these wires are more likely to enter the subintimal space and are associated with a modestly higher risk of perforation. If the difficulty is crossing the lesion because of insufficient tip load in the case of a chronic total occlusion, one may move to a specialty wire such as a Miraclebros 3–12 or a Confianza Pro 9–12 (Fig. 30.2).

Balloon catheters are meant to perform lesion dilatation. When selecting a balloon, the operator must decide on the diameter, length and compliance of the balloon. An ideal balloon to artery ratio of 0.9–1.1 is needed to minimize the risk of dissection and abrupt closure. There are three types of balloon catheters: over-the-wire, monorail, and fixed wire balloon catheters.

Over-the-wire balloon catheters have a central lumen for the guidewire and another lumen to allow for balloon inflation throughout the catheter. This system has the advantage of maintaining coronary artery access with the guidewire distal to the lesion while exchanging balloon and stent catheters. Guidewires can also be exchanged without losing arterial access by pushing the balloon to the distal portion of the artery. Because of the length of the two balloon lumens, additional personnel are needed to aid in exchange of the catheters and guidewires.

The rapid-exchange or monorail balloon catheters have a short segment that contains two lumens. One lumen, which runs the length of the catheter, is used for balloon inflation, while the second lumen is shorter and contains the guidewire. This creates a lower profile catheter and allows a single operator to exchange catheters while maintaining distal wire protection. It also allows for the use of a shorter coronary guidewire. These catheters however require more manipulation of the guidewires and balloon catheters by the operator.

The fixed-wire angioplasty balloon catheters have a balloon mounted on a central hollow wire. The guidewire and the balloon cannot be advanced independently of each other. The chief limitation of this catheter is that the balloon or wire cannot be exchanged without losing access to the vessel. These devices are no longer used.

Stents are balloon-expandable scaffolds made of stainless steel or alloys and are placed within the lesion. As with coronary balloons, stents are available in over-the-wire or monorail designs. Stents are also selected based on their diameter and length. Stents can be ‘bare-metal’ without a drug coating or ‘drug-eluting,’ that is, coated with a medication that prevents neointimal hyperplasia with consequent restensois. The first drug eluting stent (DES) was approved by the FDA in 2003 and currently there are four generations of DES. Although drug-eluting stents decrease neointimal hyperplasia, or restenosis, they have historically required a longer duration of dual anti-platelet therapy because of the increased risk of late stent thrombosis. This increase in late stent thrombosis, has been markedly mitigated with design changes in later generation DES. Bioresorbable or bioabsorbable stents are novel products now widely available in Europe, with one FDA-approved device in which the polymer which delivers the drug is resorbed over several months. The hallmark of these stents is that they are completely resorbed over time and this might conceivably counter some of the perceived limitations of durable metallic stents. These limitations include late stent thrombosis, the need for longer-term dual antiplatelet therapy, the metal scaffold interfering with vascular remodeling and coronary vasomotion and also making future surgical coronary artery bypass grafting (CABG) procedures more difficult [3–5].

Once a stenosis is identified, careful analysis of the clinical characteristics and coronary anatomy is necessary to determine whether or not the patient would be best served by percutaneous revascularization, CABG or medical therapy. A lesion classification system has been developed to categorize the anatomic risk of the lesion undergoing intervention and is related to the likelihood of a successful procedure (Table 30.1). A relatively newer scoring system called the Syntax score is used specifically to compare outcomes of PCI versus CABG surgery in multivessel disease. Patients with a low Syntax score <22 do equally well with PCI whereas those with a high Syntax score >34 tend to perform better with CABG surgery [1, 2].