When should revascularization be considered for a patient with significant coronary artery disease (CAD) and impaired renal function?

When to Revascularize in Coronary Artery Disease

Revascularization should be performed immediately in patients with STEMI or high-risk acute coronary syndromes, and in stable patients with left main disease, multivessel disease with reduced ejection fraction (<50%), or refractory angina despite optimal medical therapy. 1

Acute Coronary Syndromes

STEMI Patients

• Emergency revascularization (primary PCI) is mandatory for STEMI patients to restore flow to the infarct artery and reduce mortality. 1
• In hemodynamically stable STEMI patients with multivessel disease, staged PCI of significant non-infarct artery stenosis is recommended after successful primary PCI to reduce death or MI (Class I, Level A). 1
• Staged revascularization can be performed in-hospital or within 45 days post-STEMI, with consistent benefits regardless of timing. 1
• Do not perform routine PCI of non-infarct arteries during primary PCI in patients with cardiogenic shock due to higher risk of death or renal failure (Class III: Harm). 1

Non-STEMI/Unstable Angina

• Patients with non-STEMI and coronary anatomy amenable to revascularization should undergo revascularization (Class I). 1
• Urgency is less critical if the patient is hemodynamically and ischemia-stable, allowing time for diagnostic workup. 1

Stable Ischemic Heart Disease - Anatomic Indications

Left Main Disease

• CABG is recommended for significant left main stenosis (>50%) to improve survival (Class I, Level B-R). 1, 2
• PCI is reasonable for left main disease when it can provide equivalent revascularization to CABG (Class IIa). 1

Multivessel Disease with Reduced Ejection Fraction

• CABG is recommended for patients with multivessel CAD and severe LV systolic dysfunction (LVEF <35%) to improve survival (Class I, Level B-R). 1, 2
• In patients with LVEF 35-50%, CABG (including LIMA to LAD) is reasonable to improve survival (Class IIa). 1

Triple-Vessel Disease with Normal EF

• In patients with normal ejection fraction and triple-vessel disease (with or without proximal LAD), CABG may be reasonable to improve survival (Class IIb, Level B-R). 1
• The usefulness of PCI to improve survival in this population is uncertain (Class IIb). 1

Single or Two-Vessel Disease

• Revascularization is NOT recommended to improve survival in patients with normal LVEF and 1- or 2-vessel CAD not involving proximal LAD (Class III: No Benefit). 1

Functional/Ischemia-Based Indications

Fractional Flow Reserve (FFR) Assessment

• Patients with FFR ≤0.80 should be considered for revascularization due to increased risk of urgent readmission for unstable angina and need for target-vessel revascularization. 1
• Patients with FFR >0.80 can be safely managed medically without increased risk of death, MI, or delayed revascularization. 1
• Do not perform revascularization on coronary arteries that are not functionally significant (FFR >0.80 or <70% diameter stenosis of non-left main arteries) with the primary intent to improve survival (Class III: Harm). 1

Ischemia Testing

• Revascularization should be considered when ischemia testing demonstrates ischemia in the myocardial territory subtended by the lesion, rather than based on angiographic stenosis severity alone. 1
• High-risk features warranting revascularization include: 1
  • Early positive testing for inducible myocardial ischemia
  • Exercise-induced arrhythmias
  • Poor exercise tolerance (<3 METs) due to angina or dyspnea
  • Ischemia involving >10% of LV mass (Class IIb for silent ischemia)

Symptomatic Indications

Refractory Angina

• Revascularization is reasonable for patients with stable angina and symptoms refractory to maximal medical therapy (Class IIa, Level C). 1, 2
• Medical therapy should first include β-blockers, calcium channel blockers, and nitrates to relieve angina. 1
• If angina cannot be successfully managed or medication side effects are intolerable, proceed with revascularization. 1

Viability Assessment in Ischemic Cardiomyopathy

• In patients with ischemic cardiomyopathy (LVEF ≤35%), viability testing with cardiac MRI late gadolinium enhancement should guide revascularization decisions. 3, 4, 5
• Patients with limited myocardial scar (<6 segments with >75% transmural LGE) benefit from revascularization with significantly lower cardiac mortality (aHR 0.24). 3
• Patients with extensive myocardial scar (≥6 segments with >75% transmural LGE) do not benefit from revascularization and should receive medical treatment alone. 3

Critical Pitfalls to Avoid

• Avoid the "oculostenotic reflex": Do not revascularize based solely on angiographic stenosis severity (≥70%) in stable patients without physiological assessment or ischemia documentation. 1
• Do not perform emergency CABG after failed PCI in the setting of no-reflow phenomenon, as CABG is unlikely to improve perfusion and may cause harm. 1
• Avoid revascularization in the acute/subacute phase of Kawasaki disease with STEMI due to acute thrombotic occlusion of an aneurysm (Class III). 1
• High coronary artery calcium scores alone do not mandate invasive angiography unless symptoms or objective ischemia are present. 6

CABG vs PCI Decision-Making

• CABG is preferred over PCI for multivessel disease with acceptable surgical risk, particularly with complex anatomy, diabetes, or reduced ejection fraction. 2, 7
• Calculate the SYNTAX score to evaluate anatomic complexity and the STS score to assess surgical risk when choosing between CABG and PCI. 1, 2
• PCI should not be performed if the patient cannot tolerate or comply with dual antiplatelet therapy for the appropriate duration. 2
• Use radial artery grafts over saphenous vein grafts for the second most important target vessel after the LAD to improve patency and survival. 1