Exercise thallium-201 scintigraphy after thrombolytic therapy with or without angioplasty for acute myocardial...

Scant data are available concerning the application and results of exercise thallium-201 (Tl-201) scintigraphy after acute myocardial infarction (AMI) treated with thrombolytic therapy. The goals of this study were to determine the ability of exercise Tl-201 scintigraphy to detect inducible ischemia and to identify multivessel coronary artery disease (CAD) in 88 consecutive postinfarction patients who received thrombolytic therapy and underwent both predischarge noninvasive testing and coronary angiography. Exercise-induced Tl-201 redistribution on quantitative scintigraphy was significantly more prevalent than exercise ST-segment depression (48 vs 14%, p < 0.001). Sensitivity and specificity of exercise ST depression alone for identification of multivessel disease was 29 and 96%, respectively. Sensitivity of a remote Tl-201 defect for multivessel CAD detection was 35 and 87%, respectively--not significantly different from values for ST depression alone. When considered as a single variable, the presence of either ST depression or a remote Tl-201 defect was associated with a 58% sensitivity (p < 0.05, compared with either ST depression or Tl-201 redistribution alone), but a somewhat diminished specificity of 78%. There was no difference in extent or severity of angiographic CAD in patients with multivessel CAD with or without inducible ischemia. In conclusion, this study shows that exercise Tl-201 imaging is more sensitive than exercise Tl-201 imaging is more sensitive than exercise ST depression for detection of residual ischemia during submaximal exercise in patients who received thrombolytic therapy for AMI. The combination of the presence of either Tl-201 redistribution or ischemic ST depression was better than either variable alone for identifying patients with multivessel CAD.