Interventional Cardiology: Understanding PCI and Modern Techniques

Learn about percutaneous coronary intervention (PCI), stent technology, and when interventional approaches are preferred over medical therapy alone.

Interventional cardiology has transformed the management of coronary artery disease. Understanding when and how to intervene is crucial for optimal patient outcomes.

Indications for PCI

Class I Indications (Strongest Evidence)

STEMI: Primary PCI within 90 minutes of first medical contact
Cardiogenic shock: Regardless of time from symptom onset
Refractory angina: Despite optimal medical therapy

Class IIa Indications

High-risk stable angina: Failed medical therapy
Significant left main disease: In patients not suitable for CABG
Multi-vessel disease: With heart failure and reduced EF

Class III (Not Recommended)

Asymptomatic patients: No evidence of ischemia
Single vessel disease: With successful medical therapy
Low-risk stable angina: Without significant ischemia

Stent Technology

Bare Metal Stents (BMS)

Restenosis rate: 20-30%
Antiplatelet therapy: 1 month minimum
Use: Limited, mainly for large vessels

Drug-Eluting Stents (DES)

Restenosis rate: 5-10%
Antiplatelet therapy: 6-12 months minimum
Types: Everolimus, zotarolimus, biolimus

Key Point: DES has dramatically reduced restenosis and is now the default choice for most PCI procedures.

Bioresorbable Scaffolds

Mechanism: Temporary scaffolding, then absorbed
Status: Limited use due to scaffold thrombosis concerns
Future: Next-generation scaffolds under investigation

Antiplatelet Therapy

Dual Antiplatelet Therapy (DAPT)

Duration	Indication
1 month	High bleeding risk
6 months	Standard risk
12 months	High thrombotic risk

Agents

Aspirin: 81 mg daily, lifelong
P2Y12 inhibitor: Clopidogrel, ticagrelor, or prasugrel
Ticagrelor: Preferred for ACS (PLATO trial)
Prasugrel: Faster onset, more potent (TRITON-TIMI 38)

Complex PCI Scenarios

Left Main Disease

SYNTAX score: Guides revascularization strategy
Low syntax (0-22): PCI or CABG equivalent
High syntax (>32): CABG preferred

Chronic Total Occlusions (CTO)

Success rates: 70-90% in experienced centers
Techniques: Antegrade, retrograde, hybrid
Benefits: Improved angina, LV function

Bifurcation Lesions

Medina classification: Describes bifurcation anatomy
Strategies: Provisional stenting vs two-stent techniques
Jailed wire technique: Common approach

Invasive Physiology

Fractional Flow Reserve (FFR)

Measurement: Pressure wire across stenosis
Cutoff: FFR ≤ 0.80 indicates ischemia
Evidence: FAME trials showed improved outcomes

Instantaneous Wave-Free Ratio (iFR)

Measurement: Diastolic-only pressure ratio
Cutoff: iFR ≤ 0.89
Advantage: No adenosine required

Complications and Management

Bleeding

Access site: Radial > femoral (RIVAL trial)
Bivalirudin: Alternative to heparin
TR Band: For radial hemostasis

Contrast-Induced Nephropathy

Prevention: Hydration, minimize contrast
Risk factors: CKD, diabetes, heart failure
Monitoring: Creatinine at 24-48 hours

Stent Thrombosis

Acute: < 24 hours
Subacute: 1-30 days
Late: 1-12 months
Very late: > 12 months

Quality Metrics

Metric	Target
Door-to-balloon time (STEMI)	< 90 minutes
Radial access	> 80%
FFR/iFR use	> 30%
DAPT compliance	> 90%

Conclusion

Interventional cardiology continues to evolve with new technologies and techniques. Understanding indications, techniques, and complications will help you provide optimal care for your patients.

Explore more: Browse our interventional cardiology resources →