Cardiac CT angiography compared with myocardial perfusion stress testing on downstream resource utilization

Abstract

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.

Objectives: 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.