1. Usefulness of Coronary Computed Tomography Angiography For Early Triage of Patients with Acute Chest Pain - The Rule Out Myocardial Infarction Using Computer Assisted Tomography (ROMICAT) Trial
Udo Hoffmann, Fabian Bamberg, Claudia U. Chae, John H. Nichols, Ian S. Rogers, Sujith K. Seneviratne, Quynh A. Truong, Ricardo C. Cury, Suhny Abbara, Michael D. Shapiro, Jamaluddin Moloo, Javed Butler, Maros Ferencik, Hang Lee, Ik-Kyung Jang, Blair A. Parry, David F. Brown, James E. Udelson, Stephan Achenbach, Thomas J. Brady, John T. Nagurney
Department of Radiology, Emergency Medicine, and Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston MA

2. Disclosures
Research Grants: Siemens Medical Solutions, Amersham/GE Healthcare, Bracco Diagnostics, NIH Advisory Boards: Vital Images, Bayer Healthcare/Siemens Medical Solutions

3. Improvement of the initial ED evaluation needed!
Early Risk Stratification and Triage in the ED
6 Million present with chest pain to ED annually
ECG, initial biomarkers, and clinical presentation and traditional risk factors – no safe triage possible (Nagurney, JAMA 2006)
low threshold to admit, >80% have no ACS, $8Billion annually healthcare cost
1-5% of missed ACS cause 20% of ED malpractice costs
Improvement of the initial ED evaluation needed!

4. Preliminary coronary CTA Studies
coronary MDCT is feasible in the acute care setting
low to intermediate risk patients - absence of CAD has 100% NPV for ACS – found in 40% of patients
Hoffmann et al Circulation 2006
very low risk patients - CT may be cost saving alternative to myocardial perfusion stress testing
Raff et al JACC 2007
normal coronary CTA has excellent NPV for MACE within 15 months
Rubinshtein et al. Circulation 2007

5. Confirmation in larger cohorts Safety of Stenosis based Triage
Remaining Questions for Patient Management
Confirmation in larger cohorts
Safety of Stenosis based Triage
Relevance of detected Stenosis
Incremental Value of non-calcified plaque for exclusion of ACS

6. Determine the diagnostic accuracy of these findings for ACS
ROMICAT I - Specific Aims
Determine the prevalence of coronary atherosclerotic plaque and stenosis in patients with acute chest pain and low to intermediate for ACS
Determine the diagnostic accuracy of these findings for ACS
Determine whether this information is incremental to current risk assessment

7. Index Hospitalization
ROMICAT I – Study Design
Observational, double-blinded Cohort Study
Cardiac CT Analysis - blinded to caregiver and subjects
Presence of atherosclerotic plaque per coronary segment
Calcified plaque
Non-calcified plaque
Presence of significant coronary artery stenosis (>50%)
Neg. ECG
Neg. Trop
Standard clinical care
Acute Chest Pain
6 month FU
Index Hospitalization ED t

8. ROMICAT I - Methods positive initial Troponin Diagnostic ECG changes
Inclusion Criteria
- >5 min of chest pain <24h
- Normal initial Biomarker
- Admitted to Rule out MI
- Normal sinus rhythm
Exclusion Criteria
positive initial Troponin
Diagnostic ECG changes
Creatinine >1.3 mg/dl
- Known CAD
Coronary MDCT
- 64-slice MDCT (Siemens, Forchheim, Germany)
- Beta-Blocker if HR>65 bpm, Nitro
- ~20 ml + 80ml contrast agent (Iodhexodol 320)
- tube current: ~850 mAs, tube voltage: 120 kV
Primary Endpoint
ACS* (NSTEMI or UAP) during Index Hospitalization and MACE during 6-month follow-up adjudicated by independent committee
*According to AHA/ACC/ESC Guidelines

9. 18 month Screening and Enrollment
Protocol Eligible Subjects (n = 658)
Physician Denied (n = 19)
Patient Refusal (n = 124)
Missed to Ongoing Recruitment (n = 103)
Enrolled Subjects (n = 412)
Incomplete Scan (n=17)
Interference with Clinical Care (n = 10)
Claustrophobia/Nausea (n = 3)
Contrast Extravasation (n = 3)
Scanner Malfunction (n = 1)
Complete Scan (n=27)
History of Stent Placement (n = 10)
History of CABG (n = 17)
Study Population (n = 368)

10. ROMICAT I – Demographics and Risk Factors
Age (years, mean  SD)
52.7±12
Male Gender (n, %)
223 (61%)
Race (n, %)
African American
Caucasian
Asians
Others
31 (8%)
313 (85%)
4 (1%)
20 (6%)
No. of risk factors (median, IQR)
2 (1)
TIMI Score (low/intermediate/high) in %
94.3/ 5.4/ 0.3
ACS during index hospitalization (%, n)
Unstable angina pectoris (%, n) Myocardial infarction (%, n)
23 (74%)
8 (26%)
MACE during six month follow- up (%, n):
Recurrent chest pain:
Outpatient evaluation (PCP)
Readmission without testing
Readmission with testing
68 (18%)
50 (74%)
5 (7%)
13 (19%)

11. ROMICAT I – Prevalence of Plaque and Stenosis
CAD categories with relevance for early triage of patients with ACP in the ED
Non-obstructive Plaque %
N= 115/368
No CAD %
(no plaque and no stenosis)
N= 185/368
Significant stenosis detected or not excluded %
N= 68/368

12. Nonobstructive Plaque Significant stenosis detected or not excluded
ROMICAT I – CAD and ACS
No CAD
No ACS
Nonobstructive Plaque
7 ACS
non-stenotic ACS
small vessel disease
Significant stenosis detected or not excluded
24 ACS

13. NSTEMI with significant stenosis
40-year old male who presented 3 hours after the onset of substernal chest pain, inconclusive initial evaluation in the ED, Troponin positive 8 hours after ED presentation, underwent invasive coronary angiography with stenting of an 80% mid LAD

14. NSTEMI without significant stenosis in CT

15. NSTEMI with small vessel disease
59-year old female with typical chest pain, non-diagnostic ECG and negative serial Troponin, coronary CTA – plaque in OM 1, invasive coronary angiography demonstrates 95% stenosis of the PDA

16. NSTEMI with PDA stenosis

17. ROMICAT I – Diagnostic Accuracy
1. Triage Criterion: Presence of any plaque
ACS
No ACS
Plaque
No Plaque 31
154
183
Sens: 100% ( )
NPV: 100% ( )
Spec: 54% ( )
PPV: 17% ( )
2. Triage Criterion: Presence of significant Stenosis (>50%)
ACS
No ACS
Sign. Stenosis
No Stenosis 24 44 7
293
Sens: 77% ( )
NPV: 98% ( )
Spec: 87% ( )
PPV: 35% ( )

18. Results – Stenosis and ACS
specificity of significant stenosis for ACS was lower in subjects ≥65 years of age (58% vs. 91%) because of increased prevalence of CAC (84% vs. 39%; p<0.0001)
in 34 patients a significant stenosis was detected
20 had ACS
14 had no ACS or MACE after 6 months
severe RCA lesion, no regional LV dysfunction, normal stress SPECT study,
diagnosis of ‘non cardiac chest pain’.

19. Incremental Value of coronary CTA to TIMI
AUC for the detection of ACS during index hospitalization
Extent of plaque, presence of stenosis, TIMI risk score (AUC: 0.88, 0.82 vs. 0.63; respectively, all p<0.0001).

20. Summary
confirmation - Absence of any CAD in 50% of patients - 100% NPV for ACS – may enable early safe and early discharge from the ED
triage criterion of 50% stenosis is not perfect because of non-stenotic ACS and limited spatial resolution of coronary CTA
significant stenosis is detected in 10% of patients by coronary CTA – about 40% of these were discharged with a diagnosis of non-cardiac chest pain
incremental value of non- calcified plaque for early triage is limited

21. Thank you! Cardiac MR PET CT Program
Fabian Moselewski, Maros Ferencik, Suhny Abbara, Ricardo C. Cury, Thomas J. Brady, Javed Butler, Nina Dannemann, Michael Shapiro, Sujith Seneviratne, Ian Rogers, John Nichols, Ian Rogers, Quynh Truong, Christopher Schlett, Sam Lehman, Sujith Seneviratne, Ron Blankstein, Khuram Nasir
Department of Emergency Medicine
John T. Nagurney, David F.M. Brown, Blair Parry
Cardiology Division
Claudia U. Chae, Ik Kyung Jang, Rob Gerszten
Harvard Public School of Health
Scott Gazelle, Joseph Ladapo, Milton Weinstein