Comparison of myocardial blood flow and coronary flow reserve during dobutamine and adenosine stress: Implications for pharmacologic stress testing in coronary artery disease.
BACKGROUND
Mechanistic differences between pharmacologic stressors may offer different clinical benefits. Therefore the effects of dobutamine and adenosine on absolute myocardial blood flow (MBF) and coronary flow reserve (CFR) were compared.


RESULTS
We divided 36 patients (mean age, 61 +/- 8 years) with coronary artery disease into 2 groups based on stenosis severity as follows: greater than 50% but less than 75% (n = 16) and greater than 75% (n = 20). In addition, 18 normal volunteers (mean age, 46 +/- 7 years) served as control subjects. Groups of equal sizes received either dobutamine or adenosine. MBF at rest and peak MBF were measured by use of positron emission tomography in territories subtended by the stenosis (ischemic) and remote myocardium (remote), whereas left ventricular MBF was used in control subjects. CFR was calculated as peak MBF divided by MBF at rest. CFR was significantly greater with adenosine than with dobutamine stress in control subjects and remote CFR. Ischemic CFR was blunted to a similar degree with each stressor. Therefore adenosine achieved flow heterogeneity across all coronary stenosis severities greater than 50%. However, dobutamine achieved flow heterogeneity only in the presence of a severe coronary stenosis greater than 75% despite provoking a greater ischemic stimulus.


CONCLUSIONS
Adenosine stress demonstrated a higher sensitivity and dobutamine demonstrated a higher specificity with quantitative perfusion imaging. Therefore adenosine is superior for diagnostic perfusion imaging, whereas dobutamine is better suited in combination with visual imaging and in the functional assessment of a known coronary stenosis.
Jagathesan
Rohan
R
MRC Clinical Sciences Centre, Imperial College, London, United Kingdom.
Barnes
Edward
E
Rosen
Stuart D
SD
Foale
Rodney A
RA
Camici
Paolo G
PG
D000241:Adenosine / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D002316:Cardiotonic Agents / Q000494:pharmacology*; D003251:Constriction, Pathologic; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000473:pathology; D003326:Coronary Circulation / Q000187:drug effects*; D004280:Dobutamine / Q000494:pharmacology*; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D010477:Perfusion; D049268:Positron-Emission Tomography / Q000379:methods
D002316:Cardiotonic Agents; D004280:Dobutamine; D000241:Adenosine