Short-Term Referral Rates to Catheterization after Noninvasive Cardiac Imaging: Results from the Study of Myocardial Per

1. Short-Term Referral Rates to Catheterization after Noninvasive Cardiac Imaging: Results from the Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in CAD (SPARC) Trial 90 Day Follow-Up R Hachamovitch, JR Johnson, MA Hlatky, E. Branscomb, M.L. Ridner, R. Beanlands, B. Chow, D. Berman, L.J. Shaw, J. Lesser, P. Chareonthaitawee, BH Johnson, MS Gaber, J Hainer, M. Di Carli, for the SPARC Investigators

2. Objectives To examine the referral patterns to noninvasive cardiac imaging in patients with intermediate likelihood of CAD in a large, geographically diverse patient cohort.

3. SPARC Study – Study Design and Objectives It is a prospective, open-label, multicenter, sequentially sampled, observational registry to compare the relative clinical value of stress perfusion (SPECT and PET), and coronary CT angiography (CTA) studies in patients with known or suspected CAD with respect to post-test resource utilization and prediction of cardiac death and non-fatal myocardial infarction. Sites were required to recruit into at least 2 arms Studies performed as per routine site protocol Standardized scoring was designed to reflect the final clinical report

4. SPARC Study Design Patients With Intermediate-High Likelihood of CAD and No Prior CAD

5. SPARC Enrollment

6. Statistical Analysis All enrolled patients were considered to be members of the Intent-To-Diagnose (ITD) study cohort. Univariate differences between groups were assessed by one way ANOVA for continuous variables, and ?2 test for categorical variables. Multivariable logistic regression was used to model referral to catheterization, changes in medication use, and the combination of the two.

7. Post-Imaging Changes in Medical Rx:Categorization of Test Results To combine the results of different modalities, a single categorical variable was utilized “Normal/near normal”: Normal perfusion, normal CTA, or nonobstructive disease by CTA “Mildly abnormal”: Abnormal MPI with mild or no ischemia, obstructive CTA without “high risk” anatomic features (LM, prox LAD or 3-VD) “Severely abnormal”: Moderate to severe ischemia by MPI, obstructive CTA with “high risk” anatomic features (LM, prox LAD or 3-VD)

8. Study Cohort - Baseline Characteristics

9. Study Cohort - Baseline Characteristics

10. Unadjusted 90-day CATH: Modality vs. Test Result

11. Univariate Predictors of 90-day CATH

13. Predictors of 90-day Referral to CATH

15. Risk-Adjusted 90-day Referral to CATH

16. Predicted Referral to 90D CATH:Pts with versus without Angina

17. Changes in Post-Test Treatment:Impact of Test Results

18. Conclusions The results of all noninvasive imaging modalities examined impacted post-test referral rates to invasive catheterization Qualitatively, the likelihood of referral to catheterization is increased in proportion to the degree of test abnormality after MPI in all modalities. Quantitatively, the absolute rates of post-test referral to invasive catheterization are lower than generally thought, but consistent with previous studies. Inter-modality differences are present in post-test likelihood of referral to invasive catheterization; however,the ‘appropriateness’ of this pattern is unclear .