title: Baseline myocardial perfusion predicts response to cardiac resynchronization therapy: a prospective observational study.
abstract: OBJECTIVE
  We prospectively determined whether preimplant myocardial perfusion imaging (MPI) predicts outcome with biventricular pacing (BiVP).
  
  
  METHODS
  Single-photon emission computed tomography (SPECT) MPI, left ventricular (LV) volumes, ejection fraction (EF), 6-min hall walk (6MW) were assessed at baseline and at 4 months in 19 patients with ischemic cardiomyopathy undergoing BiVP. Clinical and hemodynamic responses were correlated with MPI.
  
  
  RESULTS
  Lower global myocardial scar burden predicted hemodynamic response to BiVP, while higher burden was associated with poor response. Clinical improvement with BiVP occurred in 12 (63%) of the patients. Clinical BiVP responders had lower rest/stress MPI score difference. There was a close negative correlation between MPI reversibility and increased 6MW distance.
  
  
  CONCLUSIONS
  Baseline MPI is associated with clinical and hemodynamic response to BiVP: greater myocardial scar burden is predictive of poor hemodynamic response, while higher ischemic burden is predictive of poor clinical response. There is a differential response to BiVP by clinical and hemodynamic criteria.
authors.affiliation: Caritas St. Elizabeth's Medical Center, 736 Cambridge Street, Boston, MA, 02135, USA, mvorlov@gmail.com
authors.forename: Michael V
authors.initials: MV
authors.lastname: Orlov
authors.forename: Michael
authors.initials: M
authors.lastname: Maysky
authors.forename: Spyridon T
authors.initials: ST
authors.lastname: Akrivakis
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ujhelyi
authors.forename: Peter
authors.initials: P
authors.lastname: Hoffmeister
authors.forename: Gunjan
authors.initials: G
authors.lastname: Shukla
authors.forename: Susan
authors.initials: S
authors.lastname: McAllister
authors.forename: Gregory
authors.initials: G
authors.lastname: Kotler
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Almasry
authors.forename: G Muqtada
authors.initials: GM
authors.lastname: Chaudhry
authors.forename: Charles I
authors.initials: CI
authors.lastname: Haffajee
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D011788:Quality of Life; D019275:Radiopharmaceuticals; D018709:Statistics, Nonparametric; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi