A patient presents for regadenoson stress testing 1 hour after having a cup of coffee. The effect of caffeine on the detection of reversible defects on myocardial perfusion SPECT imaging with regadenoson stress would be:

  1. No effect
  2. Minimal and probably clinically insignificant
  3. Substantial decrease in the detection of reversible defects
  4. Unknown

Correct Answer: C

Testing Point:

A multicenter study (Tejani, Int J Cardiovasc Imaging 30:979–989 – published online April 17, 2014) demonstrated a substantial decrease in the detection of reversible defects when caffeine was given prior to regadenoson stress:

Individuals with ≥1 segment with a reversible defect received double-blind caffeine tablets (200 or 400 mg) or placebo 90 min before a repeat regadenoson stress MPI. The majority of subjects who received caffeine shifted to a lower ischemia size category. For patients with ≥3 reversible segments, 21/23 (91%) had fewer reversible segments after receiving caffeine.

Based on this study which was previously presented in 2011 (Tejani, JNC 2011; 18:759-60), the regadenoson package insert was updated (Oct 2011): "Following caffeine administration (200 or 400 mg), the mean number of reversible defects identified was reduced by approximately 60%."

Hence, the regadenoson package insert ( recommends:

"Patients should be instructed to avoid consumption of any products containing methylxanthines, including caffeinated coffee, tea or other caffeinated beverages, caffeine-containing drug products, and theophylline for at least 12 hours before a scheduled radionuclide MPI."

The adenosine package insert ( states:

"The vasoactive effects of adenosine are inhibited by adenosine receptor antagonists, such as methylxanthines (e.g., caffeine and theophylline)…Whenever possible, drugs that might inhibit or augment the effects of adenosine should be withheld for at least five half-lives."

Given the 6 hour half-live of caffeine, this is 30 hours.

Tejani FH, Thompson RC, Kristy R, Bukofzer S. Effect of caffeine on SPECT myocardial perfusion imaging during regadenoson pharmacologic stress: a prospective, randomized, multicenter study. Int J Cardiovasc Imaging. 2014 Apr 17. [Epub ahead of print]

Regadenoson package insert:

Adenosine package insert:

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