title: Complete left bundle branch block and smaller left atrium are predictors of response to cardiac resynchronization therapy in advanced heart failure.
abstract: BACKGROUND
  We previously reported that cardiac resynchronization therapy with defibrillator (CRT-D) is not an appropriate rescue strategy in patients with advanced heart failure (HF), especially those dependent on inotrope infusion, and instead early ventricular assist device (VAD) implantation should be considered. Predictors of response to CRT in such populations, however, remain uncertain.
  
  
  RESULTS
  We studied 67 inpatients aged <65 years old with advanced HF, who received CRT-D between 2007 and 2014. Eleven patients (16%) were responders, in whom LVEF improved >10% at 6-month follow up. On logistic regression analysis, LA volume index (LAVI) <43 ml/m(2)(odds ratio (OR), 36.67; P=0.001) and complete left bundle branch block (CLBBB; OR, 6.663; P=0.032) were significant predictors of response to CRT-D among the baseline variables. Patients with both predictors were associated with improvements in LVEF and plasma B-type natriuretic peptide compared with those with none of these predictors during the 6-month follow up period (P<0.05 for both). VAD-free survival rate was significantly higher in the responders compared with the non-responders during the 2-year study period (86% vs. 52%, P=0.044).
  
  
  CONCLUSIONS
  CLBBB and smaller LAVI are novel predictors of response in patients with advanced HF receiving CRT-D in real-world practice. Such responders may be better candidates for CRT-D and delay of cardiac replacement therapy.
authors.affiliation: Department of Therapeutic Strategy for Heart Failure, Graduate School of Medicine, University of Tokyo.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Imamura
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kinugawa
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nitta
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D058409:Cardiac Resynchronization Therapy Devices; D016009:Chi-Square Distribution; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000009:adverse effects / Q000295:instrumentation / Q000401:mortality; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood; D016017:Odds Ratio; D018579:Patient Selection; D016016:Proportional Hazards Models; D020127:Recovery of Function; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D016277:Ventricular Function, Left
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain