ADENOSINE TL-201 SCAMS IN PATIENTS UNDERGOING ELECTIVE NONCARDIAC SURGERY

Dipyridamole Thallium-201 (Tl-201) scintigraphy has been used widely f or assessment of patients prior to vascular surgery. Recently, Adenosi ne has been reported to be a safe and useful alternative to Dipyridamo le. The purposes of this study were to evaluate the safety and feasibi lity of the use of Adenosine, to evaluate the correlation of Adenosine Tl-201 scans with coronary angiograms (when available) and to evaluat e the effect of scan results on clinician management style. Fifty adul ts with abdominal aortic aneurysm or other vascular disease underwent an intravenous infusion of Adenosine in conjunction with initial and d elayed planar(201)Tl scans. Images were interpreted qualitatively and quantitatively by the consensus of two or more experienced observers w ith patients showing transient left ventricular dilatation or redistri bution in one or more myocardial segments reported as being at high ri sk of peri-operative cardiac events. Of the 50 subjects studied, 49 to lerated the maximum infusion dose with 60% experiencing minor transien t symptoms. Low (n = 39) and high risk (n = 20) patients were defined according to Adenosine Tl-201 scans. Age, gender and clinical characte ristics were similar in both groups. Thirteen (65%) high risk subjects had coronary angiography compared with only three (10%) low risk pati ents. Patients with high-risk Tl-201 scans were also more likely to pr oceed to coronary revascularization prior to non-cardiac surgery [5/20 (25%) vs 1/30 (3%)]. The positive predictive value of high risk Tl-20 1 scans for coronary artery disease was 85%. Thus, Adenosine is consid ered a useful and safe alternative to Dipyridamole. In conjunction wit h Tl-201 scintigraphy Adenosine has the potential to modify management of patients prior to elective non-cardiac surgery and may reduce adve rse peri-operative cardiac events.