What is the best course of treatment for a patient with abnormal rest/stress SPECT myocardial perfusion images indicating ischemia and infarction, mildly reduced left ventricle function, and scheduled for a heart catheterization and angiogram?

Management of Ischemia and Infarction with Scheduled Catheterization

Proceed with the scheduled coronary angiography in 7 days as planned, optimize medical therapy immediately, and use the catheterization to guide definitive revascularization decisions based on coronary anatomy and physiological assessment.

Rationale for Proceeding with Angiography

Your SPECT findings demonstrate high-risk features that mandate invasive evaluation 1, 2:

• Moderate reversible ischemia at the apex indicates a functionally significant coronary stenosis requiring identification and potential revascularization 3
• Medium-sized severe fixed defect in the basal inferolateral wall represents prior infarction with potential for residual viable myocardium 1
• Post-stress LVEF of 49% (mildly reduced) is a high-risk marker that specifically warrants coronary angiography to determine if severe CAD is causing the depressed function 2, 4
• Inadequate heart rate response requiring regadenoson suggests chronotropic incompetence, which may mask the true extent of ischemia 1

The American College of Cardiology specifically recommends coronary angiography for patients with high-risk findings on non-invasive testing, which includes reduced left ventricular function (LVEF <50%) 2. Your patient's LVEF of 49% falls into the mild-to-moderate LV dysfunction category (LVEF 0.35-0.49), associated with intermediate risk 2.

Immediate Medical Optimization (Before Catheterization)

While awaiting the procedure, aggressively optimize guideline-directed medical therapy 3, 2:

• High-intensity statin therapy (atorvastatin 80mg or rosuvastatin 40mg daily) for both the ischemic and infarcted territories 2
• Aspirin 81-325mg daily unless contraindicated 2
• Beta-blocker (metoprolol, carvedilol, or bisoprolol) titrated to heart rate 50-60 bpm for both anti-ischemic effect and post-MI protection 5, 2
• ACE inhibitor or ARB given the reduced LVEF and prior infarction 2
• Sublingual nitroglycerin 0.4mg as needed for anginal symptoms, up to 3 doses every 5 minutes 5

What to Expect at Catheterization

The angiography will serve multiple critical purposes 3, 4:

1. Identify the culprit vessel(s) causing the apical ischemia - likely LAD or diagonal branch given the apical location 1
2. Assess the inferolateral territory for chronic total occlusion versus patent vessel with collateralization 1
3. Perform physiological assessment with fractional flow reserve (FFR) for intermediate lesions (40-70% stenosis) - FFR ≤0.75 indicates hemodynamically significant stenosis warranting revascularization 3, 1
4. Evaluate for multivessel disease which would favor CABG over PCI, especially if SYNTAX score >22 3

Decision Algorithm Based on Angiographic Findings

If significant stenosis (>70%) corresponds to the apical ischemia 3:

• PCI with stenting is reasonable if single-vessel or limited two-vessel disease without proximal LAD involvement 3
• CABG is preferred for complex three-vessel disease (SYNTAX score >22) or left main disease 3

If intermediate stenosis (40-70%) 3, 1:

• Measure FFR: if ≤0.75, proceed with revascularization 3, 1
• If FFR >0.80, medical therapy alone is appropriate 3
• FFR 0.75-0.80 represents a gray zone requiring clinical judgment 3

For the inferolateral infarct territory 1:

• If chronic total occlusion is found, consider PCI only if viable myocardium is demonstrated and symptoms persist despite medical therapy 1
• If patent with collaterals, medical therapy is typically sufficient 1

Critical Pitfalls to Avoid

Do not dismiss the ischemia as insignificant simply because it is "small in size" - the moderate severity combined with reduced LVEF makes this high-risk 2. The American College of Cardiology emphasizes that PCI should not be performed with the primary intent to improve survival in patients with coronary stenoses that are not anatomically or functionally significant (e.g., <70% diameter non-left main stenosis, FFR >0.80), but your patient's findings clearly exceed these thresholds 3.

Do not delay catheterization beyond the scheduled 7 days unless the patient develops unstable symptoms, in which case urgent catheterization is indicated 5. The combination of reversible ischemia and reduced LVEF warrants timely evaluation 2, 4.

Do not proceed with PCI without physiological assessment for intermediate lesions - FFR measurement prevents unnecessary stenting of non-flow-limiting stenoses 3, 1.

Post-Catheterization Management

If revascularization is performed 3:

• Dual antiplatelet therapy (aspirin + P2Y12 inhibitor) for minimum 12 months after drug-eluting stent 3
• Continue all other guideline-directed medical therapy indefinitely 2
• Cardiac rehabilitation enrollment 2

If medical therapy alone is chosen (no significant stenosis or FFR >0.80) 3:

• Intensify antianginal therapy with long-acting nitrates or ranolazine 5
• Consider repeat functional imaging in 3-6 months if symptoms persist 2
• Aggressive risk factor modification including smoking cessation, diabetes control, and hypertension management 5, 2