[Myocardial scintigraphy with thallium-201 in the evaluation of aortocoronary bypass patients].
We have compared the results of 201-Thallium scintigraphy (201 TI Sc) and those of coronary angiography in 48 patients (Pts) at a mean time of 13 months after a coronary artery by-pass grafting operation (CABG). Forty-six pts were males and 2 females, with a mean age of 52 years (range 37-66). Eighteen pts (37%) had had a myocardial infarction (MI) before the operation, 4 (8%) had a perioperative and 3 (6%) a postoperative MI. Nineteen pts (40%) had angina, 9 (19%) atypical chest pain, 6 (12%) shortness of breath or easy fatigability and 14 (29%) had no symptoms. The overall CABG patency was 74% (left anterior descending: 73%, left circumflex: 71%, right coronary artery: 80%). The 201 TI was injected at peak exercise and its myocardial uptake was recorded immediately and after four hours at rest. The 201 TI Sc has shown a sensibility (SN), specificity (SP), positive predictive (PV-pos) and negative predictive value (PV-neg) of 86, 82, 64 and 94% respectively, compared to coronary angiography. In the single patient evaluation the 201 TI Sc has shown a SN, SP, PV-pos, PV-neg of 95, 85, 82 and 96% respectively versus 90, 82, 78 and 92% of the standard exercise test associated with a positive history for 1) residual angina and 2) peri or postoperative MI. The 201 TI Sc has not shown to be significantly superior to standard exercise testing and history in the evaluation of graft patency. However it allows a topographic localization of the disease which is not feasible with the latter techniques. The 201 TI Sc can better predict the patency rather than the occlusion of the grafts because there is a high number of false positives due to residual ungrafted native disease in the territory of a good functioning graft. The 201 TI scintigraphy can give a functional evaluation of borderline grafts stenoses beside the pure anatomic definition of angiography thanks to its capability to qualitatively assess the regional myocardial blood flow during stress.
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000209:etiology; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes
La scintigrafia miocardica con Tallio-201 nella valutazione dei pazienti operati di by-pass aorto-coronarico.