Danny A. Basso, CNMT, NCT, FSNMTS Cardiac Imaging of Augusta ...

Danny A. Basso, CNMT, NCT, FSNMTS
Cardiac Imaging of Augusta
Augusta, GA

Impact of Exercise Intensity Upon
Stress Results
Percent
Heller et al Am J Cardiol 1991;68:569

Incremental vs
Submaximal
Exercise

• Roughly 50% of all stress tests performed
• Submaximal exercise SPECT MPI is
significantly less sensitive than maximal
exercise in detecting CAD and multivessel
disease.
• Pharmacologic stress agents can be divided
into vasodilators and inotropes/chronotropes.

Adenosine
Dipyridamole blocks
re-uptake of adenosine
Receptor blocker
(theophylline, caffeine)
Adenosine
EXTRACELLULAR
SPACE
CELL MEMBRANE
Adenosine
A 1 Receptor
•Slows AV
conduction
A 2B Receptor
•Peripheral vasodilation
•Bronchospasm
INTRACELLULAR
SPACE
A 2A Receptor
•Coronary vasodilation
•Peripheral vasodilation
•Sympathetic stimulation
A 3 Receptor
•Cardioprotection
•Bronchospasm

Adenosine
Dipyridamole blocks
re-uptake of adenosine
Receptor blocker
(theophylline, caffeine)
Adenosine
EXTRACELLULAR
SPACE
CELL MEMBRANE
Adenosine
A 1 Receptor
•Slows AV
conduction
A 2B Receptor
•Peripheral vasodilation
•Bronchospasm
INTRACELLULAR
SPACE
A 2A Receptor
•Coronary vasodilation
•Peripheral vasodilation
•Sympathetic stimulation
A 3 Receptor
•Cardioprotection
•Bronchospasm

• The ideal pharmacologic stressor would only
interact with the adenosine A2a receptors.

• Lexiscan is a selective A2a agonist
pharmacologic stress agent indicated for
radionuclide myocardial perfusion imaging in
patients unable to undergo adequate exercise
stress.

• 2 nd or 3 rd degree AV block
• Sinus node dysfunction
* COPD and asthma are no longer
contraindicated!

Conclusion: This pilot study showed the overall
safety of regadenoson in 49 compromised
outpatients with clinically stable moderate and
severe chronic obstructive pulmonary disease.
*Thomas et al, JNC May/June 2008

Conclusion: In this pilot safety study of 48
patients with mild or moderate asthma who
had bronchial reactivity to adenosine
monophosphate, regadenoson was safe and
well tolerated.
*Leaker et al, JNC May/June 2008

• Single-use pre-filled syringe: injection solution
containing regadenoson 0.4 mg/5ml

• No calculating doses
• No drawing of dose
• No syringe pump
• No mistakes

• Methylxanthines (caffeine, aminophylline and
theophylline) will interfere with the
vasodilatation of regadenoson. Withhold
methylxanthines for 12 hours before
regadenoson administration.
• Dipyridamole may change the effects, withhold
for at least 2 days.
• No other meds need to be withheld.

Gaemperli O, et al. J Am Coll Cardiol. 2008;51:328-329.

• Some common drugs that contain caffeine and should
be avoided for at least 12 hours before MPI with
Lexiscan
Over-the-Counter Drugs
Anacin ® (aspirin, caffeine)
Excedrin ® (acetaminophen, aspirin,
caffeine)
Vivarin ® (caffeine)
NoDoz ® (caffeine)
Prescription Drugs
Cafergot ® (ergotamine tartrate, caffeine)
Esgic ® (butalbital, acetaminophen, caffeine)
Fioricet ® (butalbital, acetaminophen, caffeine)
Fiorinal ® (butalbital, aspirin, caffeine)
Norgesic ® (orphenadrine, aspirin, caffeine)
Norgesic ® Forte (orphenadrine, aspirin, caffeine)
Synalgos ® -DC (dihydrocodeine, aspirin, caffeine)
Wigraine ® (ergotamine, caffeine)
NOTE: This is only a partial list. Please consult individual package inserts or product labels.

• Some common prescription drugs that contain
theophylline and should be withheld for at least 12
hours before MPI with Lexiscan
Aerolate ® (theophylline)
Constant-T ® (theophylline)
Elixophylline ® (theophylline)
Quibron ® (all forms) (theophylline)
Respbid ® (theophylline)
Slo-bid ® (theophylline)
Slo-Phyllin ® (theophylline)
T-Phyl ® (theophylline)
Tedral ® SA (theophylline, ephedrine HCl,
phenobarbital)
Theo-24 ® (theophylline)
Theoclear ® (theophylline)
Theo-Dur ® (theophylline)
Theolair ® (theophylline)
Theo-Organidin ® (iodinated glycerol, theophylline)
Theo-Sav ® (theophylline)
Theostat ® (theophylline)
Theo-X (theophylline)
NOTE: This is only a partial list. Please consult individual package inserts or product labels.

• Some common prescription drugs that contain dipyridamole
and should be withheld, if possible, for at least 2 days before
MPI with Lexiscan
Aggrenox ® (aspirin, dipyridamole)
Permole ® (dipyridamole)
Persantine ® (dipyridamole)
NOTE: This is only a partial list. Please consult individual package inserts or product labels.

• 5ml of Lexiscan(0.4 mg regadenoson) is
injected IV push over approximately 10
seconds in a peripheral vein. A 22 gauge or
larger catheter or needle should be used.
• Flush with 5 ml of saline.
• Inject the radiopharmaceutical 10 to 20 seconds
post flush( about 30 seconds post injection of
Lexiscan).
• Scan the patient 30 to 45 minutes post
radiopharmaceutical injection.

Duration of Effect
Isolated perfused rat heart
Coronary Conductance
(ml/min/mmHg)
0.25
0.2
0.15
0.1
adenosine
CGS21680
regadenoson
binodenoson
½ maximal
effect
0
8
16
Time (minutes)
2 4
Adapted from Gao Z et al J Pharmacol Exp Ther 2001;291(1):209-218

Δ APV (cm/sec)
70
50
30
10
Regadenoson (1 μg/kg, IV bolus)
Coronary (n=6)
Peripheral (n=5)
-10
70
0
2 4 6 8 10
Δ APV (cm/sec)
50
30
10
Adenosine (300 μg/kg, IV bolus)
Coronary (n=6)
Peripheral (n=5)
-10
0
1 2 3 4 5
Time (min)
Xu J, et al. Circulation. 2000;102 (suppl II):810.

Intracoronary APV Ratio
3.5
3.0
2.5
2.0
1.5
1.0
400-mcg Lexiscan (n=8)
400-mcg Lexiscan + aminophylline (n=4)
Time to >2.0-fold above baseline: 30 sec
Duration at ≥2.5-fold above baseline: 2.3 min
0 2 4 6 8 10
» Activation of the A 2A
adenosine receptor
by Lexiscan produces
coronary
vasodilation and
increases coronary
blood flow (CBF) 2
» Lexiscan causes a
rapid increase in CBF
that is sustained for a
short duration 2
Time, min
The effects of Lexiscan (400-mcg,

Relative Blood Flow of Stress Modalities
Blood Flow (ml/min/g)

Adverse Reaction
Lexiscan
(n=1337)
Adenoscan
(n=678)
Dyspnea 28% 26%
Headache 26% 17%
Flushing 16% 25%
Chest discomfort 13% 18%
Angina pectoris or ST-segment depression 12% 18%
Dizziness 8% 7%
Chest pain 7% 10%
Nausea 6% 6%
Abdominal discomfort 5% 2%
Dysgeusia 5% 7%
Feeling hot 5% 8%
Lexiscan (regadenoson) injection [package insert]. Deerfield, IL: Astellas Pharma US, Inc.; 2008.

SOB HA Nausea Any
Iskandrian et al, JNC Sept/Oct

*Compared to open label adenosine test
Iskandrian et al, JNC Sept/Oct 07

*Compared to open label adenosine test
Iskandrian et al, JNC Sept/Oct 07

*Compared to open label adenosine test Iskandrian et al, JNC Sept/Oct 07

• Conclusion: This phase 3 trial shows that
regadenoson provides diagnostic information
comparable to a standard adenosine infusion.
There were no serious drug-related side effects,
and regadenoson was better tolerated than
adenosine.
Iskandrian et al, JNC Sept/Oct 07

Short
Axis
Adenosine
Regadenoson
Rest
Vertical
Long-Axis
Adenosine
Regadenoson
Rest
Horizontal
Long-Axis
Adenosine
Regadenoson
Rest
Iskandrian J Nucl Cardiol. 2007;14:645-658.

• 62 year old male
• Hx of CAD
• Hx of partially torn meniscus in rt knee
• Beta blockaded

• Walk the patient on Bruce protocol until he
became fatigued and his knee started to hurt. (5
minutes)
• Injected 0.4mg regadenosine at 4minutes and
50 seconds.
• Injected radiopharmaceutical 10 to 20 seconds
later.
• Walked the patient for a total of 6.5min.

• Starting HR 59bpm BP-144/84
• Peak HR-111 (70% of APM)
• Fatigue, leg discomfort, SOB

• 64 yo female
• Chest discomfort
• Rest ECG non-specific T wave abnormalities
• ECG during Regadenoson-1 mm ST segment
depression mostly up sloping J point
depression.
• No symptoms or side effects

• A selective A 2A adenosine receptor agonist for
pharmacologic stress radionuclide MPI
• One-dose, rapid (approximately 10 seconds)
IV injection from a prefilled syringe, regardless of
body weight
• No pump required
• Simplified protocol
• Similar to Adenoscan for assessing the extent of
reversible perfusion defects by gated MPI
Lexiscan (regadenoson) injection [package insert]. Deerfield, IL: Astellas Pharma US, Inc.; 2008.