Percutaneous coronary intervention

Percutaneous coronary intervention (PCI) or percutaneous transluminal coronary angioplasty (PTCA) refers to the use of balloon angioplasty with or without placement of a stent during coronary angiography, a minimally invasive procedure. If a significant coronary stenosis is discovered during coronary angiography, it can be revascularized during the same procedure, in which case it is known as PCI.

During balloon angioplasty, a balloon is inflated in the stenosis to widen the lumen and leave space for the stent. This inflation occurs at very high pressures, usually 12 to 16 atmospheres! Very rarely, a PCI will involve only balloon angioplasty and not stent placement, in which case it’s known as plain old balloon angioplasty (POBA).

There are two types of stents, bare metal stents (BMS) and drug-eluting stents (DES). BMS’s were used previously and had a relatively high rate of in-stent re-stenosis due to intimal hyperplasia. To combat this, drug-eluting stents were developed. These stents are basically bare metal stents which elute a drug (usually everolimus or sirolimus) for a few months which prevents this in-stent restenosis. DES have no disadvantages over BMS and have basically replaced them in clinical practice.

Indications

PCI is indicated in the following cases:

• STEMI (emergent)
• NSTE-ACS with high-risk features (urgent)
• Chronic coronary syndrome:
  • Which is refractory to optimal medical therapy or:
  • In which the coronary artery disease is severe (Left main coronary artery stenosis > 50%, proximal LAD stenosis > 50%, multi-vessel disease with impaired LV function)

Whether PCI or CABG is best for the patient with chronic coronary syndrome is a difficult decision based on many factors. The following features favour PCI over CABG:

• Severe co-morbidities
• Advanced age/frail patient/reduced life expectancy
• Multi-vessel disease with low SYNTAX score
• Coronary anatomy which will likely result in incomplete revascularization with CABG

Complications

PCI is not a risk-free procedure, although the risk is fairly low. The risk for major adverse cardiac and cerebrovascular events, including death, coronary dissection, and AMI is < 0,1%. The risk for ventricular arrhythmias is 0,1%.