Equivalence between adenosine and exercise thallium-201 myocardial tomography: a multicenter, prospective, crossover trial.
OBJECTIVE
The study was designed to compare pharmacologic and exercise stress during thallium-201 single-photon tomography in a multicenter prospective crossover trial.


BACKGROUND
Both exercise and adenosine myocardial perfusion imaging have high sensitivity and specificity for detection of coronary artery disease. However, few data are available comparing these two stress tests in the same patients.


METHODS
The study group consisted of 175 subjects: 55 healthy volunteers and 120 patients with suspected coronary artery disease. All subjects underwent two thallium tomographic tests performed 30 days apart, one during intravenous administration of adenosine (140 micrograms/kg per min for 6 min) and one during exercise stress. All images were computer quantified and interpreted without knowledge of the stress test performed. Interpretation agreement was assessed by kappa and Z statistics.


RESULTS
Agreement on the presence of normal or abnormal tomograms by adenosine and exercise scintigraphy was 82.8% by visual analysis with kappa and Z statistics of 0.65 (p less than 0.0001) and 11.1 (p less than 0.00001), respectively. The agreement by computer quantification was 86% with kappa and Z statistics of 0.709 (p less than 0.0001) and 12.2 (p less than 0.00001), respectively. Agreement on localization of the perfusion defect to a specific coronary vascular territory varied from 82.7% to 91.4% with highly significant kappa and Z statistics (p less than 0.0001). There was a good correlation between quantified perfusion defect size by adenosine and exercise (r = 0.80, p less than 0.0001), but the values for defect size were significantly greater by adenosine scintigraphy (p = 0.0073). Adenosine side effects were frequent but transient and ceased spontaneously in most subjects within 1 to 2 min after the infusion was discontinued.


CONCLUSIONS
Adenosine thallium-201 scintigraphy provides diagnostic information similar to that of exercise scintigraphy, although values for defect sizes are greater with adenosine.
Nishimura
S
S
Department of Internal Medicine, Baylor College of Medicine, Houston, Texas.
Mahmarian
J J
JJ
Boyce
T M
TM
Verani
M S
MS
D000241:Adenosine; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
D013794:Thallium Radioisotopes; D000241:Adenosine