title: Incremental value of exercise echocardiography over exercise electrocardiography in a chest pain unit.
abstract: BACKGROUND
  Limited data are available on the added value of exercise echocardiography (ExEcho) over exercise electrocardiography (ExECG) in patients with suspected acute coronary syndromes (ACS) referred to a chest pain unit. We aimed to assess the incremental value of ExEcho over ExECG in this setting.
  
  
  METHODS
  ExECG and ExEcho were performed in parallel in 1052 patients with suspected ACS, nondiagnostic but interpretable electrocardiograms, and negative serial troponin results. The primary outcome was a composite of coronary death, nonfatal myocardial infarction or unstable angina with angiographic documentation of significant coronary artery disease within 6 months.
  
  
  RESULTS
  The primary outcome occurred in 2/614 patients (0.3%) with both negative ExECG and ExEcho, 3/60 (5%) with positive ExECG and negative ExEcho, 73/135 (54.1%) with negative ExECG and positive ExEcho, 106/136 (77.9%) with both positive ExECG and ExEcho, and 8/107 (7.5%) with inconclusive results. The addition of ExEcho data to a model based on clinical and ExECG data significantly increased the c statistic from 0.898 to 0.968 (change +0.070, 95% confidence interval 0.052-0.092), with a continuous net reclassification improvement of 1.56 and an integrated discrimination improvement of 22% (p<0.001). Decision curve analysis showed that a strategy of referral to coronary angiography based on ExEcho was associated with the highest net benefit and with the largest reduction in unnecessary coronary angiographies.
  
  
  CONCLUSIONS
  ExEcho provides significant incremental prognostic information and higher net clinical benefit than a strategy based on ExECG in patients referred to a chest pain unit for suspected ACS and negative troponin levels.
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain. Electronic address: alberto.bouzas.mosquera@sergas.es.
authors: Alberto
authors: A
authors: Bouzas-Mosquera
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Jesús
authors: J
authors: Peteiro
authors: Department of Health Information Technology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Francisco J
authors: FJ
authors: Broullón
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Nemesio
authors: N
authors: Álvarez-García
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Jorge L
authors: JL
authors: Rodríguez-Garrido
authors: Department of Cardiac Surgery, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Víctor X
authors: VX
authors: Mosquera
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Dolores
authors: D
authors: Martínez
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: Juan C
authors: JC
authors: Yáñez
authors: Department of Cardiology, Hospital Universitario A Coruña, A Coruña, Spain.
authors: José M
authors: JM
authors: Vázquez-Rodríguez
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000175:diagnosis*; D002637:Chest Pain / Q000209:etiology*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis*; D004452:Echocardiography; D004562:Electrocardiography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis*; D011379:Prognosis; D012372:ROC Curve; D012307:Risk Factors; D014336:Troponin / Q000097:blood
chemical_list: D014336:Troponin
keywords: Chest pain unit; Exercise echocardiography; Exercise electrocardiography; Prognosis