Prognostic value of exercise thallium-201 imaging in a community population

Background The prognostic value of exercise thallium-201 imaging has been well established in referral patient populations at tertiary care centers, but these results may be influenced by referral bias, Methods This study was performed to evaluate the prognostic value of thallium imaging in a community-based population of 446 residents of Olmsted County Minn. Eleven variables were prospectively selected and tested for their associations with outcome end points. Results Four variables (age, history of myocardial infarction, number of abnormal thallium segments on the postexercise images, and increased thallium lung uptake) contained the most independent prognostic information. For the end point overall mortality rate, the multivariate chi-square values were 17.2 (p < 0.0001) for age and 20.9 (p < 0.0001) for the number of abnormal thallium segments on the postexercise images. Five-year survival rate For patients older than the median age of 59 years with an abnormal scan was 84% versus 97% for patients less than or equal to 59 years of age with a normal scan. Conclusion Exercise thallium imaging was useful for prognostic purposes in this relatively low-risk community population, confirming the findings of referral population studies.