title: Combined electrical and global markers of dyssynchrony predict clinical response to cardiac resynchronization therapy.
abstract: OBJECTIVE
  To assess potential additional value of global left ventricular (LV) dyssynchrony markers in predicting cardiac resynchronization therapy (CRT) response in heart failure (HF) patients.
  
  
  METHODS
  We included 103 HF patients (mean age 67 ± 12 years, 83% male) who fulfilled the guidelines criteria for CRT treatment. All patients had undergone full clinical assessment, NT-proBNP and echocardiographic examination. Global LV dyssynchrony was assessed using total isovolumic time (t-IVT) and Tei index. On the basis of reduction in the NYHA class after CRT, patients were divided into responders and non-responders.
  
  
  RESULTS
  Prolonged t-IVT [0.878 (range, 0.802-0.962), p = 0.005], long QRS duration [0.978 (range, 0.960-0.996), p = 0.02] and high tricuspid regurgitation pressure drop [1.047 (range, 1.001-1.096), p = 0.046] independently predicted response to CRT. A t-IVT ≥ 11.6 s/min was 67% sensitive and 62% specific (AUC 0.69, p = 0.001) in predicting CRT response. Respective values for a QRS ≥ 151 ms were 66% and 62% (AUC 0.65, p = 0.01). Combining the two variables had higher specificity (88%) in predicting CRT response. In atrial fibrillation (AF) patients, only prolonged t-IVT [0.690 (range, 0.509-0.937), p = 0.03] independently predicted CRT response.
  
  
  CONCLUSIONS
  Combining prolonged t-IVT and the conventionally used broad QRS duration has a significantly higher specificity in identifying patients likely to respond to CRT. Moreover, in AF patients, only prolonged t-IVT independently predicted CRT response.
authors.affiliation: Public Health and Clinical Medicine, Umeå University , Umeå , Sweden.
authors.forename: Gani
authors.initials: G
authors.lastname: Bajraktari
authors.forename: Folke
authors.initials: F
authors.lastname: Rönn
authors.forename: Pranvera
authors.initials: P
authors.lastname: Ibrahimi
authors.forename: Fisnik
authors.initials: F
authors.lastname: Jashari
authors.forename: Krister
authors.initials: K
authors.lastname: Lindmark
authors.forename: Steen M
authors.initials: SM
authors.lastname: Jensen
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Henein
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology; D058406:Cardiac Resynchronization Therapy; D015897:Comorbidity; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D012372:ROC Curve; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D018487:Ventricular Dysfunction, Left
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain
keywords: cardiac resynchronization therapy; echocardiography; heart failure; predictors; total isovolumic time