title: The use of pre-test and post-test probability values as criteria before selecting patients to undergo coronary angiography in patients who have ischemic findings on myocardial perfusion scintigraphy.
abstract: OBJECTIVE
  Myocardial perfusion scintigraphy (MPS) is a diagnostic test which is frequently used in the diagnosis of coronary heart disease (CHD). MPS is generally interpreted as ischemia present or absent; however, it has a power in predicting the disease, similar to other diagnostic tests. In this study, we aimed to assist in directing the high-risk patients to undergo coronary angiography (CA) primarily by evaluating patients without prior CHD history with pre-test and post-test probabilities.
  
  
  METHODS
  The study was designed as a retrospective study. Between January 2008 and July 2011, 139 patients with positive MPS results and followed by CA recently (<6 months) were evaluated from patient files. Patients' pre-test probabilities based on the Diamond and Forrester method and the likelihood ratios that were obtained from the literature were used to calculate the patients' post exercise and post-MPS probabilities. Patients were evaluated in risk groups as low, intermediate, and high, and an ROC curve analysis was performed for the post-MPS probabilities.
  
  
  RESULTS
  Coronary artery stenosis (CAS) was determined in 59 patients (42.4%). A significant difference was determined between the risk groups according to CAS, both for the pre-test and post-test probabilities (p<0.001, p=0.024). The ROC analysis provided a cut-off value of 80.4% for post- MPS probability in predicting CAS with 67.9% sensitivity and 77.8% specificity.
  
  
  CONCLUSIONS
  When the post-MPS probability is ≥80% in patients who have reversible perfusion defects on MPS, we suggest interpreting the MPS as "high probability positive" to improve the selection of true-positive patients to undergo CA, and these patients should be primarily recommended CA.
authors.affiliation: Department of Nuclear Medicine, Kırklareli Government Hospital, Kırklareli-Turkey. drpinarkarahan@hotmail.com.
authors.forename: Nazlı Pınar
authors.initials: NP
authors.lastname: Karahan Şen
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, Dokuz Eylül University, İzmir-Turkey.
authors.forename: Recep
authors.initials: R
authors.lastname: Bekiş
authors.affiliation: Department of Public Health, Faculty of Medicine, Dokuz Eylül University, İzmir-Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Ceylan
authors.affiliation: Department of Nuclear Medicine, Faculty of Medicine, Dokuz Eylül University, İzmir-Turkey.
authors.forename: Erkan
authors.initials: E
authors.lastname: Derebek