title: The potential value of hybrid positron emission tomography/dual-source computed tomography imaging in coronary bypass surgery.
abstract: BACKGROUND
  We evaluated how comprehensive assessment of coronary artery lesions and their hemodynamic relevance by means of hybrid positron emission tomography (PET) and computed tomography (CT) imaging would affect decision-making in coronary artery bypass surgery (CABG), compared with using invasive coronary angiography (ICA) alone.
  
  
  METHODS
  After undergoing ICA, 27 patients (21 men and 6 women; mean SD age, 66 ± 10 years) planned for cardiac surgery were scheduled for myocardial perfusion stress/rest evaluation with [13N]ammonia PET and CT coronary angiography. Only ICA was available to the surgeon. Postoperatively, the performed CABG was compared with the hypothetical strategy based on hybrid PET/CT findings (regional coronary flow reserve [CFR], myocardial perfusion defects). Procedures included CABG (n = 18) alone, CABG combined with valve replacement (n = 6), and CABG combined with isolated valve replacement (n = 3). A total of 56 bypass grafts (28 venous and 28 arterial) and 66 distal anastomoses were placed.
  
  
  RESULTS
  CT evaluation showed 93% concordance (66/71) with ICA regarding significant stenoses, with sensitivity, specificity, positive predictive value, and negative predictive value of 93.1%, 98.7%, 94.4%, and 98.4%, respectively. In the PET scan, 16 patients had 1 ischemic region, and 12 patients had 1 scar region, including 5 patients who presented with mixed conditions (scar and ischemia). One patient had a completely normal myocardium. Compared with the performed surgery, PET/CT fusion evaluation showed that of the performed anastomoses, 48% had documented ischemia (with a CFR <2 in 86%), 38% were nonischemic (although a CFR value <2 was found in 78%), and 14% had scar tissue (fixed perfusion defect).
  
  
  CONCLUSIONS
  Although <50% of bypasses were placed to areas with myocardial ischemia, the CFR was low in the majority of nonischemic regions, a finding that may have important prognostic relevance. PET/CT fusion imaging could potentially influence planning for CABG and provide incremental prognostic information.
authors: Clinic for Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland. Andre.Plass@usz.ch
authors: Andre
authors: A
authors: Plass
authors: Maximilian Y
authors: MY
authors: Emmert
authors: Oliver
authors: O
authors: Gaemperli
authors: Hatem
authors: H
authors: Alkadhi
authors: Philipp
authors: P
authors: Kaufmann
authors: Volkmar
authors: V
authors: Falk
authors: Jürg
authors: J
authors: Grünenfelder
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D003657:Decision Making; D005260:Female; D006305:Health Status Indicators; D006439:Hemodynamics; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D011237:Predictive Value of Tests; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*