title: The lack of obstructive coronary artery disease on coronary CT angiography safely reduces downstream cost and resource utilization during subsequent chest pain presentations.
abstract: OBJECTIVE
  The purpose of this study is to investigate the cost and resource use due to chest pain (CP) evaluations after initial coronary CT angiography (CCTA) stratified by coronary artery disease (CAD) burden.
  
  
  METHODS
  We examined 1518 patients referred for CCTA from January 2005 to July 2012 for downstream evaluation after CCTA during a median follow-up of 351 days. Results were stratified by CAD burden as quantified on CCTA into no CAD, nonobstructive CAD (<50% stenosis), or obstructive CAD (≥50% stenosis). The incidence of ischemic testing at the time of recurrent evaluation (defined as a composite of clinic visit, emergency department encounter, or ischemic testing after the index CCTA for CP, atypical CP, or angina defined by ICD-9 code), the testing modality used, and frequency of testing were abstracted and used to calculate the direct costs of downstream utilization. Major adverse cardiovascular events defined as all-cause mortality, nonfatal myocardial infarction, stroke, or revascularization >90 days from CCTA were abstracted using ICD-9 codes and Social Security Death Index query.
  
  
  RESULTS
  A total of 174 patients (11.5%) underwent evaluation for CP after index CCTA with a higher rate of subsequent clinical visits among obstructive CAD patients compared to those with nonobstructive CAD and no CAD (17.8% vs 13.9% vs. 7.5%; P < .001). A significant reduction in the incidence of repeat ischemic testing was observed in patients with no CAD and nonobstructive CAD (P = .002). This resulted in a lower per-patient cost in the nonobstructive CAD and no CAD patients (median [interquartile range 25-75]: $2952 [$307-2952] and $235 [$0-2880]) when compared with patients with obstructive CAD (median [interquartile range 25-75]: $5832 [$5498-17,459]; P < .001). Major adverse cardiovascular events were not different in the 90 patients that underwent repeat testing at the time of CP evaluation when compared with the 84 patients for whom testing was deferred.
  
  
  CONCLUSIONS
  Absence of CAD on initial CCTA was associated with lower costs and decreased downstream utilization compared to the presence of nonobstructive and obstructive CAD on CCTA during median follow-up of 351 days.
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Dustin M
authors.initials: DM
authors.lastname: Thomas
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Shaw
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Barnwell
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Jones
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Homayoun R
authors.initials: HR
authors.lastname: Ahmadian
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Ryan L
authors.initials: RL
authors.lastname: Prentice
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Charles K
authors.initials: CK
authors.lastname: Lin
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA.
authors.forename: Taylor
authors.initials: T
authors.lastname: Triana
authors.affiliation: Noninvasive Cardiovascular Imaging Program, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Cheezum
authors.affiliation: Miami Cardiac and Vascular Institute, Baptist Health South Florida, Miami, FL, USA.
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Cury
authors.affiliation: Cardiology Service, Brooke Army Medical Center, MCHE-MDC, 3551 Roger Brooke Drive, San Antonio, TX 78234-6200, USA. Electronic address: ahmad.slim@us.army.mil.
authors.forename: Ahmad M
authors.initials: AM
authors.lastname: Slim
mesh_terms: D002637:Chest Pain / Q000191:economics* / Q000401:mortality*; D015897:Comorbidity; D017023:Coronary Angiography / Q000191:economics* / Q000706:statistics & numerical data; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D000069342:Medical Overuse / Q000191:economics / Q000517:prevention & control / Q000706:statistics & numerical data; D008875:Middle Aged; D012307:Risk Factors; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000191:economics* / Q000706:statistics & numerical data; D014481:United States; D014600:Utilization Review
keywords: CCTA; Coronary computed tomography angiography; Cost; Downstream; Recurrent chest pain; Utilization