THE PREDICTIVE VALUE OF DIPYRIDAMOLE-THALLIUM SCINTIGRAPHY FOR CARDIAC RISK ASSESSMENT BEFORE MAJOR VASCULAR-SURGERY

Background. We prospectively examined the ability of dipyridamole thal lium scintigraphy (DTS), as a preoperative screening test, to predict postoperative cardiac complications in patients undergoing peripheral arterial operations. Methods. From November 1993 to November 1995, a D TS study was routinely performed preoperatively in 167 consecutive pat ients who underwent arterial operations in our hospital. The clinician s were blinded to DTS results. The type of operation was: carotid enda rterectomy (n=53), abdominal aortic aneurysm repair (n=45), aortobifem oral bypass (n=31), femoropopliteal bypass (n=32) and others (n=6). Cl inical and scintigraphic data were collected and analyzed uni- and mul tivariantly in order to identify those variables that correlate with p ostoperative cardiac complications. Results. Fifthteen adverse cardiac events (three deaths five myocardial infarctions, seven unstable angi nas) occurred postoperatively among 167 patients (mortality: 1.8%, mor bidity: 7.2%). Forty-four patients (26.3%) had a normal scintigraphic study, sixty (35,9%) had fixed defects and sixty-three (37.7%) had rev ersible defects. The most powerful predictive factors of cardiac compl ications in the multivariate analysis were the synchronous existence o f three markers of coronary artery disease (angina pectoris, previous myocardial infarction, Q sign on EGG) and the presence of a reversible defect in the anterior segment of the left ventricle on DTS study. Co nclusions. This study demonstrates that the careful and detailed clini cal examination is of paramount importance in detecting ''high risk'' patients and that DTS should be performed as a supplementary test sinc e it offers significant information and further classifies patients of intermediate risk to develop postoperative cardiac complications.