Should a 65-year-old female with a history of coronary artery bypass grafting (CABG) 8 years ago and reversible ischemia on Lexiscan (regadenoson) stress test undergo catheterization?

Cardiac Catheterization for a 65-Year-Old Female with Previous CABG and Reversible Ischemia

A 65-year-old female with a history of coronary artery bypass grafting (CABG) 8 years ago who now shows reversible ischemia on Lexiscan stress test should undergo cardiac catheterization to evaluate for potential revascularization.

Rationale for Cardiac Catheterization

• Patients with previous CABG who demonstrate reversible ischemia on stress testing have a high likelihood of graft failure or progression of native coronary artery disease that may require intervention 1
• Coronary angiography is reasonable to further assess risk in patients with stable ischemic heart disease (SIHD) who have inconclusive prognostic information after noninvasive testing 1
• The presence of reversible ischemia on stress testing indicates an area of myocardium at risk that may benefit from revascularization to improve outcomes 1

Guidelines Supporting Catheterization in This Scenario

• The American College of Cardiology/American Heart Association guidelines indicate that coronary angiography is reasonable to further assess risk in patients with SIHD who have unsatisfactory quality of life due to angina, preserved left ventricular function, and intermediate risk criteria on noninvasive testing 1
• For patients with previous CABG who develop recurrent symptoms or ischemia, evaluation of graft patency through coronary angiography is appropriate to guide management decisions 1
• The presence of reversible ischemia on stress testing represents objective evidence of ischemia, which is a Class I indication for further evaluation 1

Risk-Benefit Assessment

• The risk of cardiac catheterization is relatively low, with major complications occurring in <1% of cases 2
• The benefit of identifying potentially treatable coronary lesions outweighs the procedural risk, especially given the documented evidence of reversible ischemia 1
• Failure to identify and treat significant coronary stenosis in a patient with documented ischemia could lead to increased morbidity and mortality 3

Management Considerations After Catheterization

• If significant native vessel disease is identified, percutaneous coronary intervention (PCI) may be preferred over repeat CABG, especially for focal lesions 4
• If graft failure is identified, the decision between PCI of the graft, PCI of the native vessel, or redo CABG should be based on:
  • Anatomical complexity of the lesions
  • Left ventricular function
  • Comorbidities
  • Patient preference 3, 4
• For severe stenosis (70-99%) identified during catheterization, functional assessment using fractional flow reserve (FFR) may help guide revascularization decisions 3

Special Considerations for Post-CABG Patients

• Saphenous vein grafts have a limited lifespan, with approximately 50% showing significant disease by 10 years post-CABG 4
• The 8-year timeframe since the patient's CABG places her at increased risk for graft stenosis or occlusion 4
• Revascularization in patients with prior CABG carries higher procedural risk than in those without prior CABG, but is still indicated when there is objective evidence of ischemia 4

Potential Pitfalls to Avoid

• Delaying catheterization in a patient with documented ischemia could lead to progression of disease and worse outcomes 5
• Relying solely on medical therapy without defining the coronary anatomy in a patient with reversible ischemia may miss an opportunity for revascularization that could improve symptoms and potentially prognosis 1, 3
• Assuming that all chest pain in post-CABG patients is non-cardiac or due to stable disease can lead to missed diagnoses of graft failure or progression of native vessel disease 6

In conclusion, given this patient's history of CABG and current evidence of reversible ischemia on Lexiscan, cardiac catheterization is indicated to evaluate coronary anatomy and guide appropriate management decisions.