Cardiac magnetic resonance with T2-weighted imaging improves detection of patients with acute coronary syndrome in the emergency department.
BACKGROUND
Cardiac magnetic resonance (CMR) imaging permits early triage of patients presenting to the emergency department with acute chest pain but has been limited by the inability to differentiate new from old myocardial infarction. Our objective was to evaluate a CMR protocol that includes T2-weighted imaging and assessment of left ventricular wall thickness in detecting patients with acute coronary syndrome in the emergency department.


RESULTS
In this prospective cohort observational study, we enrolled patients presenting to the emergency department with acute chest pain, negative cardiac biomarkers, and no ECG changes indicative of acute ischemia. The CMR protocol consisted of T2-weighted imaging, first-pass perfusion, cine function, delayed-enhancement magnetic resonance imaging, and assessment of left ventricular wall thickness. The clinical outcome (acute coronary syndrome) was defined by review of clinical charts by a consensus panel that used American Heart Association/American College of Cardiology guidelines. Among 62 patients, 13 developed acute coronary syndrome during the index hospitalization. The mean CMR time was 32+/-8 minutes. The new CMR protocol (with the addition of T2-weighted and left ventricular wall thickness) increased the specificity, positive predictive value, and overall accuracy from 84% to 96%, 55% to 85%, and 84% to 93%, respectively, compared with the conventional CMR protocol (cine, perfusion, and delayed-enhancement magnetic resonance imaging). Moreover, in a logistic regression analysis that contained information on clinical risk assessment (c-statistic=0.695) and traditional cardiac risk factors (c-statistic=0.771), the new CMR protocol significantly improved the c-statistic to 0.958 (P<0.0001).


CONCLUSIONS
The present study indicates that a new CMR protocol improves the detection of patients with acute coronary syndrome in the emergency department and adds significant value over clinical assessment and traditional cardiac risk factors.
Cury
Ricardo C
RC
Cardiac MR-PET-CT Program, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Charles River Plaza, Suite 400, Boston, MA 02114, USA. ricardocury@hotmail.com
Shash
Khalid
K
Nagurney
John T
JT
Rosito
Guido
G
Shapiro
Michael D
MD
Nomura
Cesar H
CH
Abbara
Suhny
S
Bamberg
Fabian
F
Ferencik
Maros
M
Schmidt
Ehud J
EJ
Brown
David F
DF
Hoffmann
Udo
U
Brady
Thomas J
TJ
D054058:Acute Coronary Syndrome / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000209:etiology; D015331:Cohort Studies; D003935:Diagnostic Techniques, Cardiovascular / Q000592:standards*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014218:Triage / Q000379:methods