Effect of antianginal medications on the prognostic value of exercise thallium scintigraphy.

Whether administration of antianginal medications at the time of exercise thallium scintigraphy reduces the prognostic value of this test was retrospectively examined using two year follow-up of 201 patients. Sensitivity, specificity, positive and negative predictive values and accuracy of five test outcomes for prediction of coronary events (unstable angina, myocardial infarction, cardiac death) were compared between groups of patients either taking or not taking antianginal medications. Specificity and negative predictive value of exercise and redistribution thallium scores for prediction of coronary events were greater in patients not taking antianginal medication (P less than 0.05). It was concluded that normal exercise thallium scintigraphy affords greater assurance against future coronary events in patients tested while not taking antianginal medications.