What is the best course of action for an asymptomatic patient with a history of myocardial infarction (MI), abnormal rest/stress Single Photon Emission Computed Tomography (SPECT) myocardial perfusion images, and mildly reduced left ventricle function, currently on Brilinta (ticagrelor) 60 mg twice daily, Valsartan (valsartan) 160 mg once daily, Amlodipine (amlodipine) 5 mg once daily, and Atorvastatin (atorvastatin) 40 mg once daily, scheduled for an angiogram?

Recommendation for Asymptomatic Post-MI Patient with Reversible Ischemia on SPECT

Proceed with the scheduled coronary angiography as planned, as this patient has moderate-severity reversible ischemia on stress testing despite optimal medical therapy, which warrants invasive evaluation to guide potential revascularization. 1

Rationale for Angiography

This patient meets high-risk criteria requiring coronary angiography based on objective evidence of inducible ischemia on stress imaging. 1 The key findings driving this recommendation include:

• Moderate-severity reversible perfusion defect at the apex indicating viable myocardium at risk for future events 1
• Post-stress ejection fraction of 49% (mildly reduced), though improved to 55-60% on recent echo, suggesting some recovery but still borderline function 1
• Medium-sized severe fixed defect in basal inferolateral wall consistent with prior infarction territory 1
• Inadequate heart rate response requiring pharmacologic augmentation with regadenoson, suggesting chronotropic incompetence 1

The ACC/AHA guidelines explicitly state that patients classified as not at low risk after stress testing should undergo diagnostic angiography (Level of Evidence: A). 1 This patient clearly does not meet low-risk criteria given the moderate-severity reversible ischemia and mildly reduced ventricular function.

Evidence Supporting Invasive Strategy

Studies in post-MI patients with inducible ischemia demonstrate that revascularization reduces reinfarction, hospitalizations for unstable angina, and recurrent ischemic events. 1 The DANAMI trial showed that an ischemia-guided invasive strategy in post-MI patients with positive stress tests resulted in significant reductions in adverse outcomes compared to conservative management. 1

The purpose of coronary angiography is to provide detailed information about coronary anatomy, extent of atherosclerotic obstruction, and suitability for revascularization, which directly impacts long-term prognosis. 1 Coronary angiography remains the gold standard for making revascularization determinations in patients with LV dysfunction and suspected coronary disease. 2

Current Medical Therapy Assessment

The patient's current regimen is appropriate but requires optimization:

• Ticagrelor 60 mg twice daily: This is the reduced maintenance dose, typically used for long-term secondary prevention beyond 12 months post-MI 1
• Valsartan 160 mg daily: Appropriate dosing for post-MI patients with LV dysfunction, as demonstrated in the VALIANT trial showing valsartan is as effective as captopril in high-risk post-MI patients 3, 4, 5
• Amlodipine 5 mg daily: Reasonable for blood pressure control and anti-anginal effect 1
• Atorvastatin 40 mg daily: Consider intensification to high-dose statin (80 mg) given documented CAD and ongoing ischemia 6

Post-Angiography Management Strategy

If Significant Obstructive CAD is Found:

Continue aspirin indefinitely and maintain dual antiplatelet therapy with ticagrelor. 1, 6 If revascularization is performed:

• For PCI: Continue ticagrelor for at least 12 months, potentially longer given the reduced 60 mg dose already in use 1
• For CABG: Discontinue ticagrelor 5-7 days before surgery to reduce bleeding risk, but continue aspirin perioperatively 1

Revascularization should be pursued if coronary anatomy is suitable and there is viable myocardium that is jeopardized, as evidenced by the reversible perfusion defect. 1

If No Flow-Limiting Stenoses are Found:

Continue long-term antiplatelet therapy with aspirin and implement aggressive secondary prevention measures, as recommended for patients with coronary atherosclerosis even without flow-limiting stenoses. 1, 6

Critical Pitfalls to Avoid

• Do not delay angiography based on asymptomatic status alone – objective evidence of moderate ischemia supersedes symptom status in risk stratification 1
• Do not discontinue dual antiplatelet therapy prematurely, especially if PCI is performed 6
• Avoid NSAIDs (except aspirin) due to increased cardiovascular event risk in CAD patients 6
• Do not assume the improved echo LVEF (55-60%) negates the need for angiography – the stress LVEF was 49% and reversible ischemia was demonstrated, indicating ongoing risk 1

Medication Optimization Considerations

Consider intensifying statin therapy to atorvastatin 80 mg daily given high-risk features (prior MI, ongoing ischemia, LV dysfunction). 6 The European Society of Cardiology recommends high-dose statin therapy in high-risk patients with proven coronary disease (Level of Evidence: B). 6

Beta-blocker therapy should be confirmed or initiated if not already on board, particularly given prior MI and LV dysfunction (Level of Evidence: A). 6 This was not mentioned in the current medication list and represents a potential gap in guideline-directed medical therapy.

Expected Outcomes from Angiography

The angiography will definitively establish:

• Extent and severity of coronary stenoses 1, 2
• Suitability for revascularization (PCI vs CABG vs continued medical therapy) 1
• Correlation between perfusion defects and coronary anatomy 2
• Presence of viable but hibernating myocardium in the infarct territory 1

Patients with extensive or profound inducible ischemia affecting more than 50% of remaining viable myocardium are at high risk and benefit most from revascularization. 1 This patient's moderate-severity reversible defect warrants anatomic definition to guide optimal therapy.