DOBUTAMINE TL-201 PERFUSION IMAGING IN CANDIDATES FOR LUNG TRANSPLANTATION

Background: Thallium-201 stress imaging is the most often used noninva sive test for detection of coronary artery disease. Its utility in pat ients with end-stage lung disease has not been defined. Methods: Feasi bility, safety, and reliability of thallium 201 perfusion imaging was evaluated in 23 consecutive candidates for lung transplantation. All u nderwent graded dobutamine thallium 201 single photon emission compute d tomography imaging. The perfusion imaging results were correlated wi th results of coronary angiography, radionuclide angiography, and righ t heart catheterization. Results: The testing was completed without co mplications in all patients. No perfusion abnormality was detected in five patients, and none had evidence of coronary artery disease on cor onary angiography. In 18 patients with abnormal thallium 201 imaging, coronary artery disease was detected in four patients only, and no ang iographic data was available in three patients. Thus, in at least 11 o f 23 patients, thallium 201 imaging was falsely positive. There was a trend toward lower left ventricular ejection fraction in patients with abnormal thallium 201 imaging. No correlation was found between thall ium 201 results, pulmonary artery and right atrial pressures at rest. Possible noncoronary origin of the perfusion defects include the follo wing (1) presence of sarcoid in the myocardium, (2) left ventricular a ttenuation by hypertrophied right ventricle, and (3) altered left vent ricular anatomy, function, and coronary perfusion as a result of right ventricular pressure overload. Conclusions: Dobutamine thallium 201 s tress test can be safely performed in lung transplant candidates. Howe ver, its specificity for detection of coronary artery disease is low. Selective use of coronary angiography in patients with multiple risk f actors is likely a more cost-effective approach.