title: Dual imaging stress echocardiography versus computed tomography coronary angiography for risk stratification of patients with chest pain of unknown origin.
abstract: BACKGROUND
  Dual imaging stress echocardiography, combining the evaluation of wall motion and coronary flow reserve (CFR) on the left anterior descending artery (LAD), and computed tomography coronary angiography (CTCA) are established techniques for assessing prognosis in chest pain patients. In this study we compared the prognostic value of the two methods in a cohort of patients with chest pain having suspected coronary artery disease (CAD).
  
  
  METHODS
  A total of 131 patients (76 men; age 68 ± 9 years) with chest pain of unknown origin underwent dipyridamole (up to 0.84 mg/kg over 6 min) stress echo with CFR assessment of LAD by Doppler and CTCA. A CFR ≤ 1.9 was considered abnormal, while > 50% lumen diameter reduction was the criterion for significant CAD at CTCA.
  
  
  RESULTS
  Of 131 patients, 34 (26%) had ischemia at stress echo (new wall motion abnormalities), and 56 (43%) had reduced CFR on LAD. Significant coronary stenosis at CTCA was found in 69 (53%) patients. Forty-six patients (84%) with abnormal CFR on LAD showed significant CAD at CTCA (p < 0.001). Calcium score was higher in patients with reduced than in those with normal CFR (265 ± 404 vs 131 ± 336, p = 0.04). During a median follow-up of 7 months (1st to 3rd quartile: 5-13 months), there were 45 major cardiac events (4 deaths, 11 nonfatal myocardial infarctions, and 30 late [≥6 months] coronary revascularizations). At Cox analysis, independent prognostic indicators were calcium score > 100 (HR 2.84, 95% CI 1.33-6.07, p = 0.007), significant CAD at CTCA (HR 2.68, 95% CI 1.23-5.82, p = 0.013), and inducible ischemia or CFR <1.9R on LAD on dual imaging stress echo (HR 2.25, 95% CI 1.05-4.84, p = 0.038).
  
  
  CONCLUSIONS
  Functional and anatomical evaluation using, respectively, dual imaging stress echocardiography and CTCA are both effective modalities to risk stratify patients with chest pain of unknown origin, yielding independent and comparable prognostic value. Compared to CTCA, however, stress echocardiography has the advantage of lower cost and of being free of radiations.
authors.affiliation: Division of Cardiology, Fatebenefratelli Hospital, Viale Principe di Napoli, 12 I-82100, Benevento, Italy. qciampi@gmail.com.|CNR Institute of Clinical Physiology, Pisa, Italy. qciampi@gmail.com.
authors.forename: Quirino
authors.initials: Q
authors.lastname: Ciampi
authors.affiliation: Department of Cardiology, dell'Angelo Hospital, Mestre-Venice, Italy. frigo@iol.it.
authors.forename: Fausto
authors.initials: F
authors.lastname: Rigo
authors.affiliation: Department of Cardiology, dell'Angelo Hospital, Mestre-Venice, Italy. egrolla@tin.it.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Grolla
authors.affiliation: CNR Institute of Clinical Physiology, Pisa, Italy. picano@ifc.cnr.it.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Picano
authors.affiliation: Division of Cardiology, Lucca Hospital, Lucca, Italy. lacortig@tin.it.
authors.forename: Lauro
authors.initials: L
authors.lastname: Cortigiani
mesh_terms: D002637:Chest Pain / Q000175:diagnosis* / Q000401:mortality*; D015897:Comorbidity; D017023:Coronary Angiography / Q000706:statistics & numerical data; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000401:mortality*; D025401:Echocardiography, Stress / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D064847:Multimodal Imaging / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*