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

Abstract

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