title: Computed tomography angiography and myocardial computed tomography perfusion in patients with coronary stents: prospective intraindividual comparison with conventional coronary angiography.
abstract: OBJECTIVE
  This study sought to determine whether adding myocardial computed tomography perfusion (CTP) to computed tomography angiography (CTA) improves diagnostic performance for coronary stents.
  
  
  BACKGROUND
  CTA of coronary stents has been limited by nondiagnostic studies caused by metallic stent material and coronary motion.
  
  
  METHODS
  CTA and CTP were performed in 91 consecutive patients with stents before quantitative coronary angiography, the reference standard for obstructive stenosis (≥50%). If a coronary stent or vessel was nondiagnostic on CTA, adenosine stress CTP in the corresponding myocardial territory was read for combined CTA/CTP.
  
  
  RESULTS
  Patients had an average of 2.5 ± 1.8 coronary stents (1 to 10), with a diameter of 3.0 ± 0.5 mm. Significantly more patients were nondiagnostic for stent assessment by CTA (22%; mainly due to metal artifacts [75%] or motion [25%]) versus CTP (1%; p < 0.001; severe angina precluded CTP in 1 case). The per-patient diagnostic accuracy of CTA/CTP for stents (87%, 95% confidence interval [CI]: 78% to 93%) was significantly higher than that of CTA alone (71%, 95% CI: 61% to 80%; p < 0.001), mainly because nondiagnostic examinations were significantly reduced (p < 0.001). In the analysis of any coronary artery disease, diagnostic accuracy and nondiagnostic rate were also significantly improved by the addition of CTP (p < 0.001). CTA/CTP (7.9 ± 2.8 mSv) had a significantly lower effective radiation dose than angiography (9.5 ± 5.1 mSv; p = 0.005). The area under the receiver-operating characteristic curve for CTA/CTP (0.82, 95% CI: 0.69 to 0.95) was superior to that for CTA (0.69, 95% CI: 0.57 to 0.82; p < 0.001) in identifying patients requiring stent revascularization.
  
  
  CONCLUSIONS
  Combined coronary CTA and myocardial CTP improves diagnosis of CAD and in-stent restenosis in patients with stents compared with CTA alone. (Coronary Artery Stent Evaluation With 320-Slice Computed Tomography-The CArS 320 Study [CARS-320]; NCT00967876).
authors.affiliation: Department of Radiology, Charité, Berlin, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rief
authors.forename: Elke
authors.initials: E
authors.lastname: Zimmermann
authors.forename: Fabian
authors.initials: F
authors.lastname: Stenzel
authors.forename: Peter
authors.initials: P
authors.lastname: Martus
authors.forename: Karl
authors.initials: K
authors.lastname: Stangl
authors.forename: Johannes
authors.initials: J
authors.lastname: Greupner
authors.forename: Fabian
authors.initials: F
authors.lastname: Knebel
authors.forename: Anisha
authors.initials: A
authors.lastname: Kranz
authors.forename: Peter
authors.initials: P
authors.lastname: Schlattmann
authors.forename: Michael
authors.initials: M
authors.lastname: Laule
authors.forename: Marc
authors.initials: M
authors.lastname: Dewey
mesh_terms: D000368:Aged; D057186:Comparative Effectiveness Research; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000601:surgery*; D023903:Coronary Restenosis / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D009204:Myocardial Revascularization / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D010043:Outcome and Process Assessment, Health Care; D011183:Postoperative Complications / Q000175:diagnosis*; D011446:Prospective Studies; D012372:ROC Curve; D011834:Radiation Monitoring; D015607:Stents / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: CCA; CI; CT; CTA; CTP; ISR; QCA; ROC; computed tomography; computed tomography angiography; computed tomography perfusion; confidence interval(s); conventional coronary angiography; coronary angiography; coronary vessels; diagnostic accuracy; in-stent restenosis; quantitative coronary angiography; receiver-operating characteristic; stents