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Regadenoson vs Adenosine — EECC MCQ

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ModerateCoronary Artery DiseaseRegadenoson vs AdenosineEECC

A 55-year-old man with stable angina undergoes stress perfusion cardiac MRI with regadenoson. What advantage does regadenoson have over adenosine as a vasodilator stress agent?

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Correct answer: E — Regadenoson is a selective A2A adenosine receptor agonist given as a single IV bolus — it has a more favourable side-effect profile than adenosine (less bronchospasm, no AV block) and is simpler to administer (bolus vs continuous infusion)

Adenosine (non-selective adenosine receptor agonist) requires continuous IV infusion (140 mcg/kg/min for 4-6 minutes) and activates all adenosine receptors (A1 causing AV block and bradycardia, A2B/A3 causing bronchospasm, A2A causing coronary vasodilation). Regadenoson selectively activates A2A receptors (coronary vasodilation) with minimal A1/A2B/A3 effects, given as a single 400 mcg IV bolus. Advantages: (1) simpler administration; (2) less bronchospasm (can be used cautiously in mild-moderate asthma/COPD — still relatively contraindicated in severe); (3) less AV block; (4) shorter patient discomfort duration. The 2024 ESC CCS Guidelines include both agents for pharmacological stress testing. Aminophylline should be available as an antagonist for both agents if significant side effects occur.

Reference: ESC (2024): CCS Guidelines; ASNC Guidelines