Use of exercise thallium-201 imaging for risk stratification of elderly patients with coronary artery disease

Abstract

Although coronary artery disease (CAD) may be asymptomatic, It is the most common cause of death in elderly patients in the U.S. This study examined the prognosis of 449 patients with a mean age of 65 years using exercise thallium-201 imaging. At a follow-up of 25 months, 45 patients underwent coronary artery revascularization, 8 died of cardiac causes and 10 had nonfatal acute myocardial infarctions (AMIs). Thus the total of patients with “hard” events was 18. The events included 12 of 276 patients with atypical or non-anginal symptoms versus 6 of 128 with typical angina (p = not significant); 7 of 51 patients (14%) with Q-wave AMI versus 11 of 353 (3%) without Q-wave AMI (p < 0.001); 1 of 183 patients (1%) with normal versus 17 of 221 (8%) with abnormal exercise thallium-201 images (p < 0.002); 10 of 76 patients (13%) with multi vessel thallium-201 abnormality vs 8 of 328 (2%) with no or 1-vessel thallium-201 abnormality (p < 0.001) and 10 of 96 patients (10%) with ≥3 abnormal segments by thallium-201 imaging (total segments = 9) versus 8 of 308 patients with no or <3 abnormal segments (p < 0.001). The number of segments with thallium-201 defects was 1 ± 2 in patients without and 3 ± 2 in patients with hard events (p < 0.002). Univariate and multivariate Cox survival analysis identified abnormal thallium images (chi-square = 14, p < 0.0001) and multivessel thallium-201 abnormality (chi-square = 5, p < 0.002) as independent predictors of events. The risk was <1% in patients with normal images, 5% in patients with 1-vessel thallium-201 abnormality and 13% in patients with multlvessel thallium-201 abnormality (Mantel-Cox, p < 0.0001) Thus, elderly patients with cardiac symptoms can be stratified into different risk groups based on the presence and extent of exercise-induced thallium-201 abnormality.