708-1 Defect Size with IV Dipyridamole Tc-99m Sestamibi SPECT Imaging Predicts Both Future Cardiac Events and Other Cardiac Hospitalizations

Abstract

Optimal management of patients with coronary artery disease requires identification of those at greatest risk of future adverse cardiac events. The relationship between defect size after IV dipyridamole with Tc-99m Sestamibi SPECT imaging and cardiac events (death, MI) or need for other cardiac hospitalizations for CHF, unstable angina (UA) or late revascularization (REV) (>6 months after imaging) was evaluated in 512 pts followed for 12.8 ± 9.8 months. Defects were classified as small (Sml), moderate (Mod) or large (Lrg). Of 216 pts with normal scans, there were 3 cardiac events and 11 other cardiac hospitalizations. Of the 296 pts with abnormal scans, there were 22 cardiac events (Sml 1.5%, Mod 6.9%, Lrg 12.5%) and 51 other cardiac hospitalizations (Sml 6%, Mod 12%, Lrg 20%). An abnormal scan was a significant and independent predictor of these events when compared with clinical variables. Multiple logistic regression analysis compared to normal scans (normal = 1.0) demonstrated that the defect size predicted a progressively increased likelihood of cardiac events as well as need for other cardiac hospitalizations (Figure). There was a low event rate with small defects (similar to normal scans) while the highest event rates occurred in patients with large defects. Defect size with IV dipyridamole Tc99m Sestamibi SPECT myocardial perfusion imaging is an independent predictor of future cardiac events (death, Ml) and other cardiac hospitalizations. This information may have important implications regarding the selection of patients for interventions.