Percutaneous Coronary Interventions and Other Interventional Procedures¶
Chapter 287 | Part 6: Disorders of the Cardiovascular System
KEY CLINICAL POINTS¶
- PCI is the most common revascularization procedure in the U.S., performed >900,000 times annually, with drug-eluting stents (DESs) used in ~99% of cases.
- Stent thrombosis occurs in 1–3% of patients, with late/very late events more common with first-generation DESs, but reduced with second-gen DESs and shorter DAPT.
- Restenosis rates are 20–50% with balloon angioplasty, 10–30% with bare-metal stents, and 5–15% with DESs, with DESs significantly reducing neointimal hyperplasia.
- PCI is preferred over CABG for less extensive coronary disease, while CABG is better for severe left main or multivessel disease, especially in diabetic patients.
- Structural heart interventions (e.g., TAVR, MitraClip) and peripheral artery interventions (e.g., DCBs, stents) are expanding interventional cardiology's scope.
1. DEFINITION & OVERVIEW¶
Percutaneous coronary intervention (PCI) involves balloon angioplasty and stent placement to treat coronary artery disease. Stents (metallic or biodegradable) are used to maintain vessel patency. PCI is a key revascularization strategy for acute coronary syndromes (STEMI/NSTEMI) and stable angina.
Structural Heart Intervention Devices¶
| Device Type | Common Models | Indications |
|---|---|---|
| Atrial Septal Occluder | Amplatzer ASD Occluder, Gore Atrial Septal Occluder | Closure of atrial septal defects (ASD), patent foramen ovale (PFO) |
| Mitral Valve Repair | MitraClip, PASCAL | Transcatheter edge-to-edge repair for functional mitral regurgitation |
| Aortic Valve Replacement | Sapien 3 Ultra, Evolut FX, Navitor | Transcatheter aortic valve replacement (TAVR) for severe aortic stenosis |
| Percutaneous Balloon Valvuloplasty | Balloon catheters | Treatment of valvular stenosis (aortic, mitral, pulmonic) |
1.1 Mechanisms of PCI¶
Balloon angioplasty stretches the vessel, displacing plaque and enlarging the lumen. Stents provide structural support to prevent recoil and restenosis. Drug-eluting stents (DESs) release antiproliferative agents to reduce neointimal hyperplasia.
1.2 Role in STEMI¶
PCI (primary PCI) is preferred for STEMI within 90 minutes of hospital arrival. Thrombolysis is used if PCI is delayed. Complete revascularization of nonculprit lesions improves outcomes in STEMI patients.
2. EPIDEMIOLOGY¶
PCI is the most common revascularization procedure in the U.S., performed >900,000 times annually. STEMI patients benefit most from PCI, with ~95–99% procedural success. Complications (e.g., stent thrombosis, restenosis) occur in 1–3% of cases.
2.1 Risk Factors¶
Diabetes, prior myocardial infarction, long lesions, small-diameter vessels, and suboptimal PCI increase restenosis risk. Older age (>65 years) and comorbidities (e.g., CKD, COPD) elevate procedural risk.
3. ETIOLOGY & PATHOPHYSIOLOGY¶
Atherosclerosis and thrombosis cause coronary artery stenosis. PCI disrupts plaque, leading to acute thrombosis or restenosis. DESs reduce neointimal proliferation, while biodegradable stents offer theoretical advantages in late thrombosis prevention.
3.1 Stent Types¶
Bare-metal stents (BMSs) are less effective than DESs in preventing restenosis. Second-gen DESs (everolimus, biolimus) have lower thrombosis rates. Biodegradable stents (e.g., BVS) show promise but face degradation-related risks.
4. CLINICAL FEATURES¶
Symptoms include chest pain, dyspnea, and reduced exercise tolerance. Complications include acute coronary syndrome, stent thrombosis, restenosis, and procedural risks (e.g., tamponade, embolization).
4.1 Restenosis¶
Occurs in 20–50% of balloon angioplasty cases, 10–30% with BMSs, and 5–15% with DESs. Neointimal hyperplasia is the primary mechanism.
4.2 Stent Thrombosis¶
Acute (<24h), subacute (1–30d), late (30d–1y), or very late (>1y) events. Risk factors include DAPT discontinuation, stent malapposition, and platelet dysfunction.
5. DIFFERENTIAL DIAGNOSIS¶
Differentiate PCI from CABG based on lesion complexity, patient comorbidities, and anatomical suitability. PCI is preferred for single-vessel disease, while CABG is better for multivessel or left main disease.
5.1 Lesion Classification¶
ACC/AHA classify lesions as type A (high success), B1/B2 (moderate), or C (low success). Chronic total occlusions (CTOs) are type C lesions with ~70–80% recanalization rates.
6. INVESTIGATIONS & DIAGNOSIS¶
Diagnostic tools include coronary angiography, FFR/iFR for lesion assessment, IVUS/OCT for plaque characterization, and echocardiography for LV function. FFR ≤ 0.80 indicates hemodynamically significant stenosis.
6.1 Imaging Modalities¶
IVUS and OCT provide intravascular imaging. OCT has higher resolution than IVUS but is less widely used. FFR/iFR guide revascularization decisions.
7. MANAGEMENT & TREATMENT¶
PCI involves radial/femoral access, anticoagulation (heparin, bivalirudin), and DAPT (aspirin + P2Y inhibitor). DESs are preferred for most patients. Percutaneous valve interventions (e.g., TAVR) treat structural heart disease.
7.1 Anticoagulation¶
Unfractionated heparin, enoxaparin, or bivalirudin used. Cangrelor is an IV P2Y inhibitor for patients without prior oral antiplatelet therapy.
7.2 Stent Placement¶
DESs reduce restenosis by 50% compared to BMSs. Second-gen DESs (everolimus, biolimus) have lower thrombosis rates. Biodegradable stents (BVS) show promise but face degradation risks.
8. PROGNOSIS & COMPLICATIONS¶
PCI reduces mortality in high-risk STEMI patients but carries risks of stent thrombosis (1–3%) and restenosis (5–15%). CABG has better long-term outcomes for severe multivessel disease. Complications include tamponade, embolization, and procedural mortality (0.1–0.3%).
8.1 Long-Term Outcomes¶
DESs improve outcomes compared to BMSs. CABG is superior for left main or multivessel disease, especially in diabetics. PCI is effective for stable angina but less so for complex lesions.
9. SPECIAL CONSIDERATIONS¶
PCI is preferred for less extensive disease, while CABG is better for severe left main or multivessel disease. Patients with diabetes, CKD, or COPD may benefit more from CABG. Radial access reduces bleeding risks.
9.1 Diabetes¶
CABG is associated with lower mortality than PCI in diabetic patients with multivessel disease (FREEDOM trial).
9.2 Elderly Patients¶
PCI is preferred for elderly patients with low surgical risk, while CABG is reserved for high-risk patients with complex anatomy.
10. KEY POINTS & CLINICAL PEARLS¶
PCI is the treatment of choice for STEMI and complex coronary disease. DESs reduce restenosis but require prolonged DAPT. CABG is better for left main or multivessel disease. Structural heart interventions (e.g., TAVR, MitraClip) are expanding interventional cardiology. FFR/iFR guide revascularization decisions, while IVUS/OCT optimize stent placement.