Abstract 12921: Incremental Value of Noninvasive Cardiac Imaging in Risk Prediction: Results from the SPARC Study
Background: Although SPECT, PET, and coronary CT angiography (CTA) are widely used, their incremental value and ability to risk stratify have not been reported.
Methods: We evaluated the incremental prognostic value of imaging with SPECT, PET, and CTA in 3019 patients (pts) with prior CAD (44%) or intermediate CAD likelihood recruited to the SPARC registry, over 2 years of follow up. Hard events (HE) included all cause death (ACD) and myocardial infarction (MI), and total events (TE) included HE + late revascularization (LR; >90 days post test). Test Results were normal (normal MPI, normal or nonobstructive CTA), mildly abnormal (≥10% MPI abnormal, obstructive CTA without prox LAD, left main or 3VD) or severely abnormal (=10% MPI abnormal, CTA with prox LAD, left main or 3VD). The association between test results and events was assessed using Cox Proportional Hazards analysis (CPH).
Results: At 2 years, 97 (3.2%) were lost to follow-up and 193 (6.4%) were referred to early revascularization (≤90 days post test) and were excluded from analyses. In the remaining 2729 pts, 79 HE (2.9%; 62 ACD, 17 MI) and 142 TE (5.2%) occurred. Event rates were greater after PET than SPECT or CTA, and increased across test results for all modalities. The pre imaging CPH model most predictive of HE included age, diabetes, and prior MI (χ2 55, p<0.001), the addition of imaging results revealed incremental value (χ2 64, p<0.001) and risk stratification by results (Figure). Modality used did not add significantly to the model. The pre imaging CPH model most predictive of TE included age, prior MI, prior CABG, and anginal symptoms (χ2 75, p<0.001), with added value after imaging result and modality used was added (χ2 97, p<0.001).
Conclusions: In this prospective, multicenter registry, CTA, SPECT, and PET all achieve significant risk stratification and add incremental value over pre-imaging data for the prediction of 2-year adverse events.
- © 2010 by American Heart Association, Inc.