title: Electrocardiogram-gated 18F-FDG PET/CT hybrid imaging in patients with unsatisfactory response to cardiac resynchronization therapy: initial clinical results.
abstract: The present study aimed to distinguish responders to cardiac resynchronization therapy (CRT) from nonresponders, using electrocardiogram-gated 18F-FDG PET/CT.
  
  
  METHODS
  Seven consecutive CRT nonresponders were included in the study, along with 7 age- and sex-matched CRT responders, serving as reference material. Therapy response was defined as clinical improvement (≥1 New York Heart Association class) and evidence of reverse remodeling. Besides PET/CT, we measured brain natriuretic peptide levels and assessed dyssynchrony using transthoracic echocardiography.
  
  
  RESULTS
  Compared with nonresponders, CRT responders showed significant differences in the declines of left-ventricular end-systolic volume and brain natriuretic peptide and in left-ventricular dyssynchrony (global left-ventricular entropy), extent of the myocardial scar burden, and biventricular pacemaker leads positioned within viable myocardial regions. Among the nonresponders, further therapy management was guided by the PET/CT results in 4 of 7 patients.
  
  
  CONCLUSIONS
  Cardiac hybrid imaging using gated 18F-FDG PET/CT enabled the identification of potential reasons for nonresponse to CRT therapy, which can guide subsequent therapy.
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilian's University, Munich, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Uebleis
authors.forename: Michael
authors.initials: M
authors.lastname: Ulbrich
authors.forename: Roland
authors.initials: R
authors.lastname: Tegtmeyer
authors.forename: Franziska
authors.initials: F
authors.lastname: Schuessler
authors.forename: Nadine
authors.initials: N
authors.lastname: Haserueck
authors.forename: Johannes
authors.initials: J
authors.lastname: Siebermair
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker
authors.forename: Stephan
authors.initials: S
authors.lastname: Nekolla
authors.forename: Paul
authors.initials: P
authors.lastname: Cumming
authors.forename: Peter
authors.initials: P
authors.lastname: Bartenstein
authors.forename: Stefan
authors.initials: S
authors.lastname: Kääb
authors.forename: Marcus
authors.initials: M
authors.lastname: Hacker
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D004562:Electrocardiography; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18