708-4 Can the Results of SPECT Scintigraphy Safely Guide Clinical Management of Patients with Active CAD?

Myocardial perfusion scintigraphy is increasingly used to categorize risk in pts with known or a high likelihood of CAD. This strategy will only be cost-effective if: 1) cardiologists will largely reserve further testing such as angiography (angio) to high-risk subsets; and 2) it is shown that less severe patterns of abnormality can be safely managed medically. We previously reported angio rates after all 4, 162 SPECT studies (excluding those with angio within 90 days beforeSPECT) at our cardiology practice-based nuclear lab: 4% (69/1663) in pts with fixed defects only and/or no ischemia; 60% (682/1141) in pts with high-risk ischemia (2 of multivessel or LAD distribution ischemia and abnormal lung uptake); and 9% (123/1352) for pts with mild-moderate ischemia. In this study, we determined outcome of the 1229 pts with mild-moderate ischemia who did not have referral for angio. Patient characteristics: mean age 65 yrs; known CAD=1061 (86%); prior CABG=344; prior MI=575; prior PTCA=674; angina=592. Twenty-eight (2%) pts were lost to follow-up. The remainder were followed for a mean of 18 months. There were 22 hard events (MI=15; cardiac death=71) (1.8%) and 54 pts required PTCA or CABG (total event rate 6.3%). Mean time to any event was 13.2 months from SPECT. Freedom from hard events at 1 yr was 99% and at 2 yrs 97%. Freedom from any event was 97% at 1 yr and 91% at 2 yrs.Conclusions1) SPECT can be a highly effective strategy for selecting pts for angio; 2) Even in a self-referral setting angio is largely reserved for pts with high-risk scans; and 3) Pts with mildly-moderately abnormal scans can be treated safely with medical therapy and close follow-u