What is the best course of management for a 63-year-old female patient with a positive pharmacologic stress test showing epigastric chest pressure, prolonged QT interval at baseline, and a small fixed perfusion defect, but no significant regional wall motion abnormalities or ischemic ECG changes, and a left ventricular ejection fraction (LVEF) of 63%?

Management of Positive Pharmacologic Stress Test with Small Fixed Perfusion Defect and Preserved LVEF

This patient falls into a low-risk category and can be managed conservatively with guideline-directed medical therapy without proceeding to invasive coronary angiography. 1

Risk Stratification Analysis

This patient's stress test results place her definitively in the low-risk category based on established noninvasive risk stratification criteria:

• Normal LVEF of 63% (well above the high-risk threshold of <35%) 1
• Small fixed perfusion defect (likely artifact) rather than stress-induced reversible ischemia 1
• No significant regional wall motion abnormalities 1
• No high-risk markers such as LV dilation, increased lung uptake, or extensive ischemia 1
• Improved perfusion compared to prior study (previous large LAD and LCx defects now resolved) 1

According to ACC/AHA guidelines, patients with normal or small myocardial perfusion defects at rest or with stress have an annual mortality rate of less than 1%, defining them as low-risk 1. The epigastric chest pressure without ischemic ECG changes further supports a non-high-risk presentation 1.

Clinical Interpretation of Findings

The Small Fixed Defect

The report explicitly states this is "most likely consistent with breast attenuation artifact" 1. Even if this represents a tiny prior MI rather than artifact, the key prognostic factors remain favorable:

• Fixed (not reversible) defects indicate scar, not active ischemia 1
• Small size carries minimal prognostic significance 1
• No associated wall motion abnormality 1

Symptom-Perfusion Mismatch

The presence of epigastric chest pressure during stress without corresponding perfusion defects or ischemic ECG changes suggests either:

• Non-cardiac etiology of symptoms 1
• Microvascular dysfunction (not amenable to revascularization) 1
• Esophageal or gastrointestinal source 1

Critical caveat: While rare (0.9% of cases), ischemic ECG changes with normal perfusion images during vasodilator stress can indicate false-negative results from balanced ischemia, particularly in older women 2. However, this patient had no ischemic ECG changes, making this scenario unlikely 2.

Recommended Management Algorithm

1. Initiate Guideline-Directed Medical Therapy 1

• Antiplatelet therapy (aspirin or P2Y12 inhibitor if indicated)
• High-intensity statin therapy
• Beta-blocker (particularly important given prolonged QT at baseline)
• ACE inhibitor or ARB if hypertensive or diabetic
• Optimize risk factor modification (blood pressure, diabetes, smoking cessation)

2. Address the Prolonged QT Interval 1

• Review all medications for QT-prolonging agents
• Check electrolytes (potassium, magnesium, calcium)
• Consider cardiology consultation if QTc >500 ms or symptomatic
• Avoid additional QT-prolonging medications

3. Monitor Clinically 1

• Reassess symptoms with medical therapy
• Repeat stress testing only if:
  • Symptoms worsen despite optimal medical therapy 1
  • New symptoms develop suggesting higher-risk features 1
  • Clinical deterioration occurs 1

4. Do NOT Proceed to Coronary Angiography 1

Invasive angiography is not indicated because:

• Patient does not meet high-risk criteria requiring direct catheterization 1
• No evidence of severe LV dysfunction (LVEF <35%) 1
• No recurrent rest angina despite medical therapy 1
• No hemodynamic compromise 1
• Stress test demonstrates low-risk features 1

Comparison to Prior Study

The marked improvement from the prior study showing large LAD and LCx perfusion defects (now resolved) with LVEF improvement from 56% to 63% suggests either:

• Successful prior revascularization (if performed)
• Resolution of stunning or hibernating myocardium
• Prior study artifact that has been corrected

This improvement further supports the current low-risk status and conservative management approach 1.

When to Reconsider Invasive Strategy

Proceed to coronary angiography only if the patient develops 1:

• Recurrent rest angina despite intensive medical therapy
• Hemodynamic instability
• Severe symptoms limiting quality of life despite medical therapy
• New high-risk features on repeat stress testing (large reversible defects, extensive ischemia, LV dysfunction)

Special Consideration for Women

This patient demographic (63-year-old woman) has specific considerations 3, 2:

• Exercise ECG alone has limited diagnostic value in women 3
• Stress imaging (as performed here) provides superior diagnostic and prognostic information 3
• False-negative results with ischemic ECG changes during vasodilator stress occur predominantly in older women (88% in one series) 2
• However, absence of ischemic ECG changes in this case makes false-negative result unlikely 2

The negative predictive value of normal stress imaging in women is excellent, with cardiac event rates <1% annually 3, supporting conservative management in this case.