Should an elderly female patient with hypertension (HTN), diabetes mellitus (DM), hyperlipidemia (HLD), and paroxysmal atrial fibrillation (PAF) complaining of atypical chest pain receive a Lexiscan (regadenoson) stress test?

Should This Elderly Female Receive a Lexiscan Stress Test?

Yes, pharmacologic stress testing with Lexiscan (regadenoson) is appropriate for this elderly female patient with multiple cardiac risk factors and atypical chest pain, as she represents a high-risk population where noninvasive cardiac imaging is indicated to evaluate for stable ischemic heart disease. 1, 2

Rationale for Stress Testing in This Patient

This patient's clinical profile warrants cardiac evaluation:

• Multiple cardiovascular risk factors including hypertension, diabetes mellitus, and hyperlipidemia significantly increase her likelihood of coronary artery disease, and these risk factors should be aggressively evaluated in elderly patients 1
• Atypical chest pain in elderly women is frequently cardiac in origin despite not meeting "typical" angina criteria, as women and elderly patients commonly present with atypical symptoms 1, 3
• Paroxysmal atrial fibrillation increases her risk for both thromboembolic events and underlying structural heart disease 1

Why Lexiscan Specifically?

Regadenoson (Lexiscan) is FDA-approved as a pharmacologic stress agent for radionuclide myocardial perfusion imaging in patients unable to undergo adequate exercise stress 2:

• Elderly patients with multiple comorbidities (HTN, DM, HLD, PAF) often cannot achieve adequate exercise capacity for diagnostic exercise stress testing 1
• Regadenoson has been studied extensively in elderly patients, with 56% of study participants ≥65 years and 24% ≥75 years 2
• The safety profile in elderly patients (≥75 years) is similar to younger patients, with only a slightly higher incidence of hypotension (2% vs ≤1%) 2

Critical Considerations for Atypical Chest Pain in Elderly Women

Do not dismiss atypical symptoms as noncardiac based on presentation alone—what is considered "atypical" is based on male symptom patterns and systematically leads to underdiagnosis in elderly women 3, 4, 5:

• Elderly women with acute coronary syndromes present with dyspnea, nausea/vomiting, and indigestion more frequently than chest pain 4, 6
• Chest pain as a chief complaint and "typical" chest pain characteristics are NOT significantly associated with ACS in elderly patients, unlike in younger patients 5
• Different clinical variables predict cardiac disease in elderly versus younger patients 5

Pre-Test Evaluation Required

Before proceeding with Lexiscan stress testing:

• Obtain 12-lead ECG to exclude acute ischemic changes, prior MI, or conduction abnormalities that would alter management 1
• Assess for contraindications including severe bronchospasm or high-grade AV block (though less common with regadenoson than adenosine) 2
• Medication review: Patients should avoid methylxanthines (caffeine, theophylline, aminophylline) for at least 12 hours before regadenoson administration 2
• Continue cardiac medications: Beta-blockers, calcium channel blockers, ACE inhibitors, nitrates, and angiotensin receptor blockers do not need to be held and were safely continued in clinical studies 2

Management of Paroxysmal Atrial Fibrillation

Anticoagulation should be prescribed for this patient with heart failure risk factors and paroxysmal atrial fibrillation to prevent thromboembolic events (Class I recommendation) 1:

• The combination of HTN, DM, and PAF places her at elevated stroke risk
• Ventricular rate control with beta-blockers is recommended for patients with heart failure and atrial fibrillation 1

Common Pitfalls to Avoid

• Do not attribute symptoms to aging or anxiety without comprehensive cardiac workup, as elderly women are systematically underdiagnosed 3, 5
• Do not delay evaluation based on "atypical" presentation—this terminology is misleading in elderly women 1, 3
• Do not assume exercise stress testing is feasible—elderly patients with multiple comorbidities frequently cannot achieve adequate exercise capacity 1, 2
• Do not withhold beta-blockers or other cardiac medications before the Lexiscan test, as these were safely continued in clinical trials 2

Expected Outcomes and Next Steps

If stress testing reveals:

• Significant ischemia: Coronary angiography is recommended according to guidelines for patients with heart failure and angina 1
• Normal perfusion: Continue guideline-directed medical therapy for risk factor control (HTN, DM, HLD) 1
• Equivocal results: Consider coronary CT angiography or invasive angiography based on clinical suspicion 1