1013-108 Is Persantine Thallium Scintigraphy Cost Effective and Reliable in the Preoperative Evaluation of Patients Referred for Peripheral Vascular Surgery?

Abstract

Asymptomatic CAD has been shown to be associated with a high risk of perioperative cardiac events in patients (pts) undergoing surgery for peripheral vascular disease (PVD). Dipyridamole thallium (SPECT) scintigraphy (DTS) is considered the most useful screening test for stratification of these pts. Comparative prospective evaluation of various noninvasive tests for detection of latent CAD in PVD pts is lacking. In this study, 100 consecutive patients referred for PVD surgery were evaluated by DTS, low work load exercise treadmill test (ETT) and ambulatory ECG monitoring (AEM). Pts with abnormal findings on any of the three noninvasive tests were evaluated with coronary angiography (angio) for further stratification. Fifty-five pts had reversible perfusion defects on DTS. Of the 55 + pts with DTS, 49 had data on AEM with 39% having evidence of ambulatory ischemia; 48 of the 55 pts performed ETT with ischemia induced in 13%. Of the 41 pts with normal DTS findings, 12 (29%) had ischemia during ETT (n = 6) or AEM (n = 6); 64% of these pts had multi-vessel CAD by angio. Statistical modeling and analysis of important clinical variables, AEM ischemia, and angio findings were compared with DTS for predicting CAD. These analyses revealed that family hx of CAD, chest pain, smoking, age ≥ 65 years, and ischemia on AEM were highly predictive of CAD with a positive predictive value of 89% and a specificity of 92%. These findings suggest that a careful evaluation of clinical parameters and AEM results can provide reliable and clinically meaningful data predictive of significant CAD in pts referred for PVD surgery. Our data have demonstrated that the findings on DTS are not always reliable and its routine use might not be warranted in preoperative evaluation of patients with asymptomatic CAD referred for peripheral vascular surgery.