Myocardial perfusion imaging for evaluation and triage of patients with suspected acute cardiac ischemia: a randomized controlled trial.
BACKGROUND
Observational studies of acute myocardial perfusion imaging in emergency department (ED) patients with chest pain have suggested high sensitivity and negative predictive value for acute cardiac ischemia, but use of this method has not been prospectively tested.


OBJECTIVE
To assess whether incorporating acute resting perfusion imaging into an ED evaluation strategy for patients with suspected acute ischemia but no initial electrocardiogram (ECG) changes diagnostic of acute ischemia improves clinical decision making for initial ED triage.


METHODS
Prospective, randomized controlled trial conducted at 7 academic medical centers and community hospitals between July 1997 and May 1999 among 2475 adult ED patients with chest pain or other symptoms suggestive of acute cardiac ischemia and with normal or nondiagnostic initial ECG results.


METHODS
Patients were randomly assigned to receive either the usual ED evaluation strategy (n = 1260) or the usual strategy supplemented with results from acute resting myocardial perfusion imaging using single-photon emission computed tomography with injection of 20 to 30 mCi of Tc-99m sestamibi (n = 1215), interpreted in real time by local staff physicians and with results provided to the ED physician for incorporation into clinical decision making.


METHODS
Appropriateness of triage decision either to admit to hospital/observation or to discharge directly home from the ED.


RESULTS
Among patients with acute cardiac ischemia (ie, acute myocardial infarction [MI] or unstable angina; n = 329), there were no differences in ED triage decisions between those receiving standard evaluation and those whose evaluation was supplemented by a sestamibi scan. Among patients with acute MI (n = 56), 97% vs 96% were hospitalized (relative risk [RR], 1.00; 95% confidence interval [CI], 0.89-1.12), and among those with unstable angina (n = 273), 83% vs 81% were hospitalized (RR, 0.98; 95% CI, 0.87-1.10). However, among patients without acute cardiac ischemia (n = 2146), hospitalization was 52% with usual care vs 42% with sestamibi imaging (RR, 0.84; 95% CI, 0.77-0.92).


CONCLUSIONS
Sestamibi perfusion imaging improves ED triage decision making for patients with symptoms suggestive of acute cardiac ischemia without obvious abnormalities on initial ECG. In this study, unnecessary hospitalizations were reduced among patients without acute ischemia, without reducing appropriate admission for patients with acute ischemia.
Udelson
James E
JE
Division of Clinical Care Research, Tufts-New England Medical Center, 750 Washington St, Box 70, Boston, MA 02111, USA. judelson@Lifespan.org
Beshansky
Joni R
JR
Ballin
Daniel S
DS
Feldman
James A
JA
Griffith
John L
JL
Handler
Jonathan
J
Heller
Gary V
GV
Hendel
Robert C
RC
Pope
J Hector
JH
Ruthazer
Robin
R
Spiegler
Ethan J
EJ
Woolard
Robert H
RH
Selker
Harry P
HP
D000208:Acute Disease; D000789:Angina, Unstable / Q000175:diagnosis / Q000000981:diagnostic imaging; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000000981:diagnostic imaging*; D010043:Outcome and Process Assessment, Health Care; D010351:Patient Discharge / Q000706:statistics & numerical data; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D014218:Triage
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi