Revascularization Strategies in Ischemic Heart Disease

Introduction

Coronary revascularization is a fundamental therapeutic strategy for patients with ischemic heart disease. The main goal is to restore blood flow in stenotic coronary arteries, improving myocardial perfusion and reducing the risk of acute ischemic events.

The two main revascularization techniques are:

Percutaneous Coronary Intervention (PCI): A minimally invasive procedure that involves dilating the stenosis with a balloon and implanting a stent to keep the vessel open.
Coronary Artery Bypass Grafting (CABG): A surgical procedure that creates a vascular bridge (graft) to bypass coronary stenoses using arteries or veins harvested from the patient.

Indications for Revascularization

The decision regarding the revascularization strategy depends on several factors, including the extent of coronary artery disease, left ventricular function, and the presence of symptoms refractory to medical therapy.

The main indications include:

Acute Coronary Syndrome (STEMI/NSTEMI): Primary PCI or early revascularization based on risk stratification.
Symptomatic stable angina: Revascularization is indicated in patients with persistent symptoms despite optimal medical therapy.
Multivessel coronary artery disease: CABG is preferred in patients with left main coronary artery involvement or left ventricular dysfunction.
Severe documented ischemia: Revascularization is necessary in patients with evidence of inducible ischemia affecting large myocardial areas.

Percutaneous Coronary Intervention (PCI)

Percutaneous coronary intervention is a minimally invasive technique that treats coronary stenoses using a balloon catheter and stent implantation.

Procedure

Vascular access: Typically via the radial or femoral artery.
Balloon dilation: Expansion of the stenosis by controlled inflation.
Stent implantation: Placement of a metallic stent to maintain vessel patency.

Types of Stents

Bare Metal Stents (BMS)
- 🛠 Material: Stainless steel, cobalt-chromium, or platinum-chromium.
- ✅ Advantages: Less need for prolonged antiplatelet therapy, suitable for patients at high bleeding risk.
- ❌ Disadvantages: High risk of restenosis (10-30%) due to neointimal proliferation; less commonly used today compared to DES.
Drug-Eluting Stents (DES)
- 🛠 Material: Metallic structure (cobalt-chromium or platinum-chromium) with a polymer coating containing antiproliferative drugs (sirolimus, everolimus, zotarolimus, paclitaxel).
- ✅ Advantages: Significantly reduces restenosis risk compared to BMS, available in multiple generations with improved drugs and polymers.
- ❌ Disadvantages: Requires dual antiplatelet therapy for at least 6-12 months, potential risk of late thrombosis (lower in newer-generation DES).
Bioresorbable Scaffolds (BRS)
- 🛠 Material: Biodegradable polymers (polylactic acid - PLLA) or bioabsorbable metallic alloys (magnesium).
- ✅ Advantages: Dissolves over time, leaving the artery free of permanent structures, potentially lower risk of long-term complications.
- ❌ Disadvantages: Larger initial scaffold structure, higher thrombosis risk compared to current DES, limited use due to issues with early generations.

Advantages and Disadvantages

Advantages: Less invasive, short recovery times, can be performed in emergency settings.
Disadvantages: Risk of restenosis (especially with BMS), need for dual antiplatelet therapy for at least 6-12 months.

Coronary Artery Bypass Grafting (CABG)

Coronary artery bypass grafting is a surgical procedure that creates a new blood flow route to bypass coronary obstructions.

Procedure

Graft harvesting: The internal mammary artery, radial artery, or saphenous vein is typically used.
Anastomosis: The graft is connected proximally to the aorta and distally to the coronary artery beyond the stenosis.
Cardiopulmonary bypass: May be used to support the heart during surgery.

Preferred Indications for CABG

Three-vessel coronary artery disease with left ventricular involvement.
Critical stenosis of the left main coronary artery.
PCI failure or recurrent restenosis.

Advantages and Disadvantages

Advantages: Lower restenosis risk, better survival in patients with extensive disease.
Disadvantages: Invasive procedure, prolonged hospitalization, risk of perioperative complications.

Post-Revascularization Follow-up

After revascularization, proper follow-up is essential to reduce the risk of restenosis, stent thrombosis (in PCI), or graft occlusion (in CABG), as well as to prevent new ischemic events.

Monitoring and Pharmacological Therapy

Dual Antiplatelet Therapy (DAPT): After PCI, Clopidogrel, Ticagrelor, or Prasugrel + Aspirin for at least 6-12 months, depending on thrombosis or bleeding risk. After CABG, Aspirin is generally sufficient, though Clopidogrel may be added for 12 months in some cases.
Risk Factor Management: Monitoring and controlling cholesterol, blood pressure, glucose levels, and lifestyle factors to reduce the risk of new coronary lesions.
Cardiac Rehabilitation: Structured programs including supervised exercise, nutritional support, and patient education to improve prognosis and quality of life.
Specialist Follow-up: Regular cardiology visits with ECG, echocardiogram, and stress testing to monitor cardiac function and therapy effectiveness.

Comparison Between PCI and CABG

Characteristic	PCI (Angioplasty)	CABG (Bypass Surgery)
Invasiveness	Minimally invasive (percutaneous access)	Major surgery (sternotomy or mini-thoracotomy)
Procedure duration	30-90 minutes	3-6 hours
Anesthesia	Local + sedation	General anesthesia
Hospital stay	1-3 days	5-10 days
Recovery	Fast (days)	Longer (weeks-months)
Main indications	Single or non-extensive coronary lesions	Multivessel disease, diabetes, left ventricular dysfunction
Post-procedure therapy	Dual antiplatelet therapy for 1-12 months	Aspirin long-term (+ DAPT for 1 year in selected cases)
Benefit duration	Risk of restenosis over time, especially with drug-eluting stents	More durable, especially with arterial grafts
Need for repeat procedure	Higher in patients with diffuse coronary artery disease	Less common but possible in the long term
Main complications	Stent thrombosis, dissection, bleeding	Infection, stroke, heart failure, graft occlusion
Perioperative mortality	<1% in elective procedures	1-3% (higher in emergency or high-risk cases)
Survival benefit	Similar to CABG in less complex cases	Better survival in high-risk patients
Emergency approach (MI/STEMI)	First-line choice for rapid revascularization	Reserved for selected cases (PCI failure, shock)

Conclusion

The choice between PCI and CABG must be personalized based on the patient's clinical characteristics and the severity of coronary artery disease. Both strategies play a crucial role in managing ischemic heart disease and should be integrated with optimal medical therapy to achieve the best long-term outcomes.

References

Vrints C, et al. 2024 ESC Guidelines for the management of chronic coronary syndromes. European Heart Journal. 2024;45(36):3415-3526.
Neumann FJ, et al. 2018 ESC/EACTS Guidelines on myocardial revascularization. European Heart Journal. 2019;40(2):87-165.
Patel MR, et al. Appropriate use criteria for coronary revascularization. J Am Coll Cardiol. 2021;78(7):813-834.
Park SJ, et al. PCI versus CABG in left main coronary artery disease. NEJM. 2020;382(2):139-148.
Stone GW, et al. Five-year outcomes with PCI versus CABG in multivessel coronary disease. NEJM. 2019;381(9):799-809.