What are the basic principles of percutaneous coronary intervention (PCI) in patients with a history of coronary artery bypass grafting (CABG)?

Basic Principles of Graft PCI

PCI should be performed in patients with early ischemia (within 30 days) after CABG when technically feasible, and distal embolic protection devices must be used when performing saphenous vein graft interventions. 1

Timing-Based Approach to Graft PCI

Early Ischemia (< 30 days post-CABG)

• Urgent coronary angiography is indicated to define the anatomic cause of ischemia and determine optimal therapy 1
• Early ischemia typically reflects graft failure from thrombosis, affecting both saphenous vein and arterial grafts 1
• Emergency PCI of focal graft stenosis or recanalization of acute graft thrombosis successfully relieves ischemia in the majority of patients 1
• Balloon dilation across suture lines can be performed safely within days of surgery 1
• Intra-aortic balloon pump support should be considered in the context of systemic hypotension or severe LV dysfunction, as flow in vein graft conduits is pressure-dependent 1
• Intracoronary fibrinolytic therapy should be administered with caution during the first week postoperatively; mechanical thrombectomy with newer catheter technologies may be more effective without hemorrhage risk 1

Intermediate Period (1-3 years post-CABG)

• PCI is reasonable in patients with preserved LV function and discrete lesions in graft conduits 1
• Ischemia during this period usually reflects peri-anastomotic graft stenosis 1
• Distal anastomotic stenoses (both arterial and venous) respond well to balloon dilation alone and have more favorable long-term prognosis than mid-shaft or proximal vein graft stenoses 1
• Coronary stent deployment may enhance immediate results in mid-shaft, ostial, or distal anastomotic vein graft stenoses 1

Late Ischemia (> 3 years post-CABG)

• PCI is reasonable in patients with diseased vein grafts more than 3 years after CABG 1
• Late ischemia typically reflects development of new stenoses in graft conduits and/or native vessels 1
• Slow-flow occurs more frequently in grafts with diffuse atherosclerotic involvement, angiographically demonstrable thrombus, irregular or ulcerative lesion surfaces, and long lesions with large plaque volume 1

Mandatory Technical Considerations

Embolic Protection

• Distal embolic protection devices must be used when technically feasible in patients undergoing PCI to saphenous vein grafts 1
• This is a Class I recommendation based on studies demonstrating efficacy in reducing complications 1

Native Vessel vs. Graft Intervention

• PCI is reasonable for disabling angina secondary to new disease in native coronary circulation after CABG (objective evidence of ischemia should be obtained if angina is not typical) 1
• PCI is reasonable when technically feasible in patients with a patent left internal mammary artery graft who have clinically significant obstructions in other vessels 1
• Native vessel PCI is associated with better long-term outcomes compared to graft PCI, with lower mortality, readmission rates, and need for repeat revascularization 2, 3

Absolute Contraindications

Do Not Perform PCI in These Scenarios:

• Chronic total vein graft occlusions - associated with high complication rates and low rates of sustained patency 1
• Multiple target lesions with multivessel disease, failure of multiple SVGs, and impaired LV function unless repeat CABG poses excessive risk due to severe comorbid conditions 1

Critical Pitfalls to Avoid

Lesion Selection Errors

• Final patency after PTCA is greater for distal SVG lesions than for ostial or mid-SVG lesions 1
• Stenosis location is a better determinant of final patency than graft age or type of interventional device used 1
• Event-free survival is less favorable following angioplasty of totally occluded SVGs, ostial vein graft stenoses, or grafts with diffuse or multicentric disease 1

Procedural Approach

• If feasible, PCI of both bypass graft and native vessel offending stenoses should be attempted, particularly if intracoronary stents can be successfully deployed 1
• Incomplete revascularization and unbypassed native vessel stenoses or stenoses distal to a bypass graft anastomosis may precipitate recurrent ischemia 1

Long-Term Outcome Considerations

• Patients with prior bypass surgery who undergo successful PCI have long-term outcomes dependent on patient age, degree of LV dysfunction, and presence of multivessel coronary atherosclerosis 1
• Best long-term results are observed after recanalization of distal anastomotic stenoses occurring within 1 year of operation 1
• Graft PCI compared to native vessel PCI is associated with higher risk of overall mortality (HR 1.15), all-cause readmission (HR 1.16), readmission for PCI (HR 1.25), and composite of myocardial infarction and revascularization (HR 1.23) 2
• Coexistent multisystem disease may influence long-term outcomes in this population 1