title: Influence of cardiac stress protocol on myocardial perfusion imaging accuracy: The role of exercise level on the evaluation of ischemic burden.
abstract: Some specifics of cardiac stress protocols, i.e., stressor used or exercise level achieved, may impact myocardial perfusion imaging (MPI) accuracy.
  
  
  
  Four-hundred and seventy-five patients were submitted to MPI and coronary angiography. MPI was performed after exercise (303 patients) or dipyridamole stress (172 patients). A coronary stenosis ≥70% was considered significant. In case of exercise test, a peak heart rate (HR) <85% of the maximal age predicted was considered submaximal and categorized as follows: >75% and <85% ("Group 1"); <75% ("Group 2").
  
  
  
  At coronary angiography, 312/475 (66%) patients showed significant stenosis. In the overall population, MPI showed a high accuracy in unmasking significant coronary stenosis, independently of the stress protocol adopted (AUC .76 for exercise vs .78 for vasodilator; P = NS). However, in case of an exercise stress test, a significant interaction between peak %HR and MPI diagnostic power was evident. While an elevated accuracy was still maintained in "Group 1" patients (AUC .79; P vs maximal exercise = NS), a significant drop was demonstrated in "Group 2" patients (AUC .66; P vs maximal exercise = .012, and P vs "Group 1" = .042).
  
  
  
  The accuracy of MPI is not influenced by the stress protocol adopted. Exercise MPI maintains an elevated accuracy as long as the %HR remains >75%.
authors: Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, 56124, Pisa, Italy.
authors: Alessia
authors: A
authors: Gimelli
authors: Cardio-Thoracic and Vascular Department, University Hospital of Pisa, Pisa, Italy. riccardo.liga@gmail.com.
authors: Riccardo
authors: R
authors: Liga
authors: Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, 56124, Pisa, Italy.
authors: Emilio Maria
authors: EM
authors: Pasanisi
authors: Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, 56124, Pisa, Italy.
authors: Mirta
authors: M
authors: Casagranda
authors: Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, 56124, Pisa, Italy.
authors: Michele
authors: M
authors: Coceani
authors: Fondazione Toscana Gabriele Monasterio, Via Moruzzi 1, 56124, Pisa, Italy.|CNR, Institute of Clinical Physiology, Pisa, Italy.
authors: Paolo
authors: P
authors: Marzullo
mesh_terms: D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D005082:Physical Exertion; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
keywords: CZT; Myocardial perfusion imaging; exercise stress test; ischemic heart disease; pharmacological stress test