Abstract 262: A Comparative Study of the Efficiency of Non-Invasive Imaging Modalities in the Evaluation of Outpatient Chest Pain and the Sequential Relationship between Coronary Imaging Modalities Leading to Percutaneous Coronary Interventions at the Patient Level

Abstract

Background: As catheterizations can lead to complications, assessing chest pain patients for coronary artery disease with non-invasive methods has the potential to improve the quality of care. However, there is limited evidence comparing subsequent procedures following initial assessments. To investigate the role of coronary computed tomographic angiography (CCTA) as an initial assessment, this study had two aims: 1) quantify catheterizations following initial non-invasive workups, and 2) evaluate the rate of stent placement following either initial CCTA assessment or catheterization without CCTA. Methods: This was a retrospective analysis using administrative claims data from a large, national health insurer with a cardiac utilization management program. To assess the first aim, patients diagnosed with chest pain who received one of the following initial assessments in 2010 were selected: stress echocardiogram (STE), cardiac nuclear scan (CNUC), or CCTA. Continuous enrollment for 24 months after the initial assessment and no prior chest pain diagnosis or related-procedure in the year prior to the index procedure was required. The number of patients receiving 1, 2, and 3 procedures, as well as the proportion of patients with a catheterization following their initial assessment was reported. To assess the second aim, patients who had either an initial CCTA or a catheterization with no CCTA during 2011-2012 were selected. Patients receiving a stent prior to the CCTA or catheterization were excluded. The rate of stent placement in the 30 days after the initial CCTA assessment or the catheterization was compared for each group using a two-tailed t-test. Results: CNUC was the most common initial procedure. Among the initial assessments, 50.4% of Medicare patients with CNUC had a catheterization, compared to 26.8% with CCTA and 21.6% with STE. Most of the Medicare patients had 1 procedure; 36.1% had 2 or more procedures and 12.0% had 3 procedures. The evaluation of stent placement found that stents were more common in the group that had a catheterization but no CCTA (22.2%) compared to the group that had an initial CCTA assessment (7.4%), p<0.001. Among those with an initial CCTA, 30.2% had a catheterization and 24.6% of those went on to have a stent. The difference in the rate of transition from catheterization to stent in the two populations was not statistically significant, p=0.37. Conclusions: These results suggest that CCTA or STE as an initial, non-invasive cardiac procedure may reduce cardiac catheterization, thereby reducing radiation exposure and risk of complications from invasive tests. The rate of stent placement was lower among those who had an initial CCTA assessment, compared to when catheterization was used alone. CCTA’s role can be clarified through prospective, randomized studies.