Coronary artery disease after heart transplantation: non-invasive evaluation with exercise thallium scintigraphy

In order to assess the value of exercise thallium scintigraphy for the detection and prognosis of graft coronary artery disease, 50 heart transplant patients (mean age 46.7 +/- 11.5 years) were studied within 48 h of their scheduled yearly coronary angiography and subsequently followed up for a mean of 13 +/- 3 months. Angiography revealed normal coronary arteries in 35 patients, and coronary artery disease in 15 (two with type A lesions, seven with type B lesions and six with both). Seven patients had one or more stenoses > or = 50%. Exercise thallium scintigraphy was negative in all patients with normal coronary arteries (100% specificity), and abnormal in 10 of 15 patients with coronary artery disease (67% sensitivity). Fixed defects were seen in six cases, transient defects in two and both in two; the results of the test were abnormal in all seven patients with > or = 50% lesions. During follow-up, none of the patients with a normal exercise thallium scintigraphy experienced any cardiac event; in the group with abnormal results, four cardiac events occurred. Although further studies are needed to confirm these results, exercise thallium scintigraphy seems to be useful in evaluating post-transplant coronary artery disease: it is accurate in detecting the most severe stenoses and provides some prognostic information.