What is PCI (Percutaneous Coronary Intervention)?

What is PCI (Percutaneous Coronary Intervention)?

PCI is a catheter-based procedure that uses balloon inflation and typically stent placement to open narrowed or blocked coronary arteries, performed through arterial access under local anesthesia without requiring open-heart surgery. 1

Core Procedural Definition

PCI encompasses a broad range of catheter-based techniques for treating coronary artery stenosis, including:

• Intracoronary stent implantation (both bare-metal and drug-eluting stents) 1
• Balloon angioplasty to dilate narrowed vessels 2
• Atherectomy devices (directional, rotational, and extraction) for plaque modification 1
• Thrombectomy catheters and embolic protection devices for thrombus management 1

The procedure is performed by accessing an artery (typically radial or femoral), advancing a catheter to the coronary arteries under fluoroscopic guidance, and treating the stenotic lesion. 2

Technical Success Criteria

Angiographic success is defined as stenosis reduction to <20% with optimal flow, reflecting improved outcomes with modern stent technology. 1

Procedural success requires angiographic success plus absence of major in-hospital complications, including death, myocardial infarction, and emergency coronary artery bypass surgery. 1

Any attempt (successful or unsuccessful) to treat a stenosis by any technique, or even failed attempts to cross the stenosis with a wire or device, counts as PCI. 2

Clinical Applications by Presentation

Stable Coronary Artery Disease

• PCI is recommended for patients with significant stenoses (>70% diameter) and unacceptable angina despite medical therapy. 1
• PCI serves as a valuable initial mode of revascularization in patients with objective evidence of large ischemia in most lesion subsets. 1, 3
• The exception is chronic total occlusions that cannot be crossed. 3

ST-Elevation Myocardial Infarction (STEMI)

• Primary PCI is the treatment of choice for STEMI when performed by experienced teams at PCI-capable hospitals. 1, 3
• Primary PCI is superior to thrombolysis with lower rates of death, reinfarction, and stroke. 1, 3
• The superiority is especially clinically relevant for the time interval between 3 and 12 hours after symptom onset. 2

Non-ST-Elevation Acute Coronary Syndromes (NSTE-ACS)

• Early angiography (≤48 hours) and PCI show clear benefit only in high-risk groups. 3
• Routine stenting is recommended based on predictability of results and immediate safety. 2

Procedural Urgency Classification

PCI procedures are classified by urgency at the time the operator decides to perform the intervention: 2

• Elective: Can be performed on an outpatient basis without significant risk of infarction or death; cardiac function has been stable in days or weeks prior. 2
• Urgent: Performed on an inpatient basis before discharge due to significant concerns about risk of ischemia, infarction, and/or death. 2
• Emergency: For acute presentations requiring immediate intervention. 2
• Salvage: For patients in extremis, such as cardiogenic shock. 2

PCI Versus CABG: Decision Algorithm

CABG is preferred over PCI in the following scenarios:

• Complex 3-vessel disease (SYNTAX score >22) to improve survival 1, 3
• Multivessel disease with diabetes mellitus, particularly when left internal mammary artery grafting to LAD is feasible 1, 3
• Significant left main coronary artery disease in patients who are candidates for CABG 3

PCI is appropriate when:

• Single-vessel or less complex multivessel disease is present 3
• Patient is not a surgical candidate 2
• Focal saphenous vein graft lesions exist in patients who are poor candidates for reoperative surgery 2

PCI outcomes versus CABG show similar mortality and myocardial infarction rates in appropriate patient subsets. 1

Critical Success Factors and Requirements

Dual antiplatelet therapy (aspirin plus thienopyridine) is mandatory for PCI patients. 1, 3

Experienced operators and catheterization laboratory teams are essential for optimal outcomes, with a higher level of experience required for primary PCI in STEMI than for stable CAD. 1, 3

The procedure start time is defined as when local anesthetic was first administered for vascular access, or the time of the first attempt at vascular access (whichever is earlier). 2

Absolute Contraindications to PCI

PCI should not be performed in patients who:

• Do not meet anatomic (>50% left main or >70% non-left main stenosis) or physiological criteria for revascularization 3
• Are not likely to tolerate and comply with dual antiplatelet therapy for the appropriate duration based on the type of stent implanted 3
• Have insignificant disease (less than 50% coronary stenosis) 2

Common Pitfalls to Avoid

Do not perform multivessel PCI routinely in all patients with STEMI and multivessel disease; the 2015 ACC/AHA/SCAI guidelines upgraded this from Class III (Harm) to Class IIb (may be considered in selected patients), but this does not endorse routine performance. 2

Integrate clinical data, lesion severity/complexity, and risk of contrast nephropathy when determining optimal strategy and timing. 2

For STEMI, primary PCI should be directed only at the infarct-related coronary artery (culprit vessel), with decisions about PCI of non-culprit lesions guided by objective evidence of residual ischemia at later follow-up. 3