Abstract 18942: Coronary CT Angiography versus Stress Imaging for Initial Risk Stratification (CT-FIRST): A Randomized Prospective Trial on Downstream Resource Utilization
Introduction: Noninvasive stress myocardial imaging studies are commonly utilized to evaluate patients with chest pain. While coronary computed tomographic angiography (CTA) is highly accurate for the diagnosis of coronary artery disease (CAD), its comparative effectiveness versus stress imaging on downstream resource utilization is undefined.
Hypothesis: We assessed the hypothesis that coronary CTA may be associated with lower downstream resource utilization as compared to stress imaging.
Methods: We randomized 240 adults without prior CAD who were clinically referred for stress imaging (single photon emission computed tomography [SPECT] or stress echocardiography) to subsequent 64-slice CTA versus stress imaging alone (1:1). CTA readers were blinded to clinical and stress test results and patients were prospectively followed over 24 months for the primary outcome of mean per-patient downstream clinical evaluations and additional cardiac testing (composite) for the initial anginal complaint.
Results: Patient were of mean age 52 ± 9 years (58% male) with mean pre-test probability (Diamond-Forrester) of 44 ± 20%. Most (67%) underwent SPECT (86% exercise), with 37% undergoing exercise stress echocardiography. Stress imaging studies demonstrated ischemia in 5% of subjects. Coronary CTA was normal in 52% with 40%, 5% and 1% having mild (<50%), moderate (50-69%) and severe (>70%) stenosis, respectively. Most patients (67%) underwent no further posttest evaluation. Coronary CTA was associated with significantly fewer total downstream encounters (0.4; 95% CI -0.5-1.4) versus no CTA (1.3; 0.9-1.6; p=0.02) and fewer clinic and emergency room visits per-subject (0.29 vs. 1.03; p=0.04). Downstream stress tests, catheterizations, revascularizations and acute coronary events were similar between groups. Discrepancies between CTA and stress imaging were rare (3 abnormal SPECT with normal CTA) and 9% of CTA patients required follow-up for incidental findings. There were no significant differences in aspirin or statin medication utilization.
Conclusions: Among a stable symptomatic cohort with low CAD prevalence undergoing stress imaging, coronary CTA was associated with incrementally lower rates of downstream clinical evaluations.
- © 2013 by American Heart Association, Inc.