Abstract 14932: Improved Outcome Prediction by SPECT-MPI After CT-Attenuation Correction
Purpose: The aim of this study was to determine whether attenuation correction with computed tomography (CT-AC) improves the prognostic value of single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) compared to non-corrected SPECT-MPI.
Methods: In 876 consecutive patients undergoing a 1-day stress/rest 99mTc-tetrofosmin SPECT-MPI for evaluation of known or suspected coronary artery disease summed stress score (SSS, 20-segment model) was obtained from filtered back projection (FBP) and iterative reconstruction with CT-AC. Survival free of major adverse cardiac events (MACE, cardiac death or nonfatal myocardial infarction) and survival free of any adverse cardiac events (including cardiac hospitalization, unstable angina and late coronary revascularization) as well as independent predictors for events were analyzed by cox regression analysis.
Results: At a mean follow-up of 2.3 ± 0.6 years, a total of 184 adverse events occurred in 145 patients, including 35 MACE (16 cardiac deaths (rate 1.8%) and 19 nonfatal myocardial infarction (rate 2.2%)). Using FBP a SSS 0–3 identified best patients with low MACE rate (0.6%), while an intermediate MACE rate was comparably found at SSS 4–8 (4.3%) and SSS 9–13 (3.8%). By contrast, with CT-AC the discrimination of low from intermediate MACE rate was best observed between SSS 0 (0%) to SSS 1–3 (3.7%), with a plateau at SSS 4–8 (3.2%). In patients with FBP SSS>3 a CT-AC SSS>0 yielded a significant incremental value to predict MACE.
Conclusions: CT-AC for SPECT-MPI adds incremental prognostic value allowing improved risk stratification. The prognostically relevant SSS cut off is shifted towards lower values.
- © 2010 by American Heart Association, Inc.