Cardiac CT angiography compared with myocardial perfusion stress testing on downstream resource utilization.
BACKGROUND
Nuclear myocardial perfusion stress (MPS) testing and cardiac computed tomographic angiography (CCTA) are commonly used noninvasive tests. Limited studies exist comparing their clinical and cost outcomes.


OBJECTIVE
We compared the clinical and cost outcomes of MPS with CCTA in a symptomatic cohort.


METHODS
We retrospectively identified 241 symptomatic patients without known coronary artery disease (CAD) who underwent MPS between May 2006 and April 2008. A comparison group of 252 age- and sex-matched symptomatic patients without known CAD underwent 64-slice CCTA during the same period. The primary outcome was the per-patient rate of posttest clinical evaluations and cardiac testing for the presenting symptom. Total direct costs were also compared.


RESULTS
The group consisted of 44% women of mean age 53 ± 10 years. There were no differences in risk factors or pretest probability of obstructive CAD (83% intermediate risk) between groups. During mean follow-up of 30 ± 7 months, we found no difference between CCTA and MPS in per-patient rates of any posttest evaluation or testing, 24.6% versus 27.7% (P = 0.44), respectively. CCTA patients had lower utilization of invasive angiography (3.3% vs 8.1%; P = 0.02) and a nonsignificant trend toward reduced downstream cardiac testing (11.5% vs 17.0%; P = 0.08). Including the evaluation of significant incidental findings (7.1% in CCTA), mean direct costs were significantly lower using CCTA ($808; 95% CI, $611-$1005) compared with MPS ($1315; 95% CI, $1105-$1525; P <0.001).


CONCLUSIONS
Low-intermediate risk patients without known CAD who underwent CCTA, compared with MPS, had similar rates of posttest evaluations, fewer invasive catheterizations, and lower overall evaluation costs.
Cardiology Service, Walter Reed Army Medical Center, Building 2, Room 4A-34A, 6900 Georgia Avenue NW, Washington, DC 20307, USA.
Michael K
MK
Cheezum
Edward A
EA
Hulten
Allen J
AJ
Taylor
Barnett T
BT
Gibbs
Sidney R
SR
Hinds
Irwin M
IM
Feuerstein
Aaron L
AL
Stack
Todd C
TC
Villines
D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D017023:Coronary Angiography / Q000191:economics / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000191:economics / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000191:economics / Q000379:methods*
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi