EXERCISE TL-201 SCINTIGRAPHY AFTER THROMBOLYTIC THERAPY WITH OR WITHOUT ANGIOPLASTY FOR ACUTE MYOCARDIAL-INFARCTION

Scant data are available concerning the application and results of exe rcise thallium-201 (Tl-201) scintigraphy after acute myocardial infarc tion (AMI) treated with thrombolytic therapy. The goals of this study were to determine the ability of exercise Tl-201 scintigraphy to detec t inducible ischemia and to identify multivessel coronary artery disea se (CAD) in 88 consecutive postinfarction patients who received thromb olytic therapy and underwent both predischarge noninvasive testing and coronary angiography. Exercise-induced Tl-201 redistribution on quant itative scintigraphy was significantly more prevalent than exercise ST -segment depression (48 vs 14%, p < 0.001). Sensitivity and specificit y of exercise ST depression alone for identification of multivessel di sease was 29 and 96%, respectively. Sensitivity of a remote Tl-201 def ect for multivessel CAD detection was 35 and 87%, respectively - not s ignificantly different from values for ST depression alone. When consi dered as a single variable, the presence of either ST depression or a remote Tl-201 defect was associated with 58% sensitivity (p < 0.05, co mpared with either ST depression or Tl-201 redistribution alone), but a somewhat diminished specifity of 78%. There was no difference in ext ent or severity of angiographic CAD in patients with multivessel CAD w ith or without inducible ischemia. In conclusion, this study shows tha t exercise Tl-201 imaging is more sensitive than exercise ST depressio n for detection of residual ischemia during submaximal exercise in pat ients who received thrombolytic therapy for AMI. The combination of th e presence of either Tl-201 redistribution or ischemic ST depression w as better than either variable alone for identifying patients with mul tivessel CAD.