Prognostic role of stress thallium test in patients with significant coronary artery disease.

OBJECTIVE: The benign outcome of patients with a normal exercise thallium-201 myocardial perfusion study has been well established. The aim of the study was to examine the prognostic implications of normal exercise tomographic thallium images in medically treated patients with angiographic evidence of coronary artery disease (CAD). METHODS: There were 68 patients in Group A with significant angiographic CAD (54 male and 14 female) aged 52 +/- 12 years, 42 had one, 18 had two and eight had three vessel CAD (50% diameter stenosis 1, Group B had 70 patients who had normal coronary arteries at cardiac catheterization. RESULTS: Exercise test was submaximal in 40 (50.82%) patients, ST segment depression during exercise occurred in 28 patients (41.1%) and angina during exercise in 24 patients (35.2%). Majority of patients (76.47%) were on anti-anginal therapy. During a mean follow up of 30 months only two patients had cardiac events in group A patient. One died of cardiac causes and one had non fatal myocardial infarction (event rate 0.96%/year). None of these 2 patients had positive ST response during exercise. In group B only one patient had non-fatal myocardial infarction. CONCLUSION: Medically treated CAD patients including those with multivessel CAD have a benign prognosis in the presence of normal exercise thallium images. These results have long term important implication in management of such patients and cost of health delivery.