title: Male gender and chronic obstructive pulmonary disease predict a poor clinical response in patients undergoing cardiac resynchronisation therapy.
abstract: OBJECTIVE
  Current guidelines advocate cardiac resynchronisation therapy (CRT) in patients with class III/IV New York Heart Association (NYHA) heart failure, depressed left ventricular function and a broad QRS. However, a significant proportion of patients do not derive any benefit from CRT. The aim of this study was to identify clinical, electrocardiographic and echocardiographic predictors of response to CRT.
  
  
  METHODS
  A retrospective analysis of patients undergoing CRT in our institution was performed. A favourable clinical response to CRT was defined as an improvement in NYHA Heart failure class of ≥ 1 and lack of hospitalisation with heart failure. Comparisons were made between responders and non-responders in terms of baseline characteristics and potential predictors of CRT response (QRS width, presence of left bundle branch block, atrial fibrillation, evidence of mechanical dyssynchrony on echocardiography and LV lead position).
  
  
  RESULTS
  A total of 164 patients had full follow-up data. The mean follow-up was 293 days. Of patients undergoing CRT, 90 (58.9%) had a favourable clinical response to CRT. Predictors of a lack of clinical response to CRT were male gender (p = 0.012) and chronic obstructive pulmonary disease (COPD) (0.008). Pre-implant echocardiographic dyssynchrony assessment appeared not to predict response to CRT (p = 0.87); however, there was a trend towards a positive response in those patients with significant dyssynchrony (p = 0.09) defined as interventricular delay > 40 ms or maximal LV delay of > 80 ms.
  
  
  CONCLUSIONS
  Male gender and coexisting COPD were shown to be independent predictors of non-response to CRT in this cohort of patients fulfilling current criteria for CRT.
authors.affiliation: Cardiothoracic Centre, Guy's and St. Thomas' Hospital NHS Trust, London, UK. senthilk1uk@yahoo.co.uk
authors.forename: S
authors.initials: S
authors.lastname: Kirubakaran
authors.forename: A
authors.initials: A
authors.lastname: Ladwiniec
authors.forename: A
authors.initials: A
authors.lastname: Arujuna
authors.forename: M
authors.initials: M
authors.lastname: Ginks
authors.forename: M
authors.initials: M
authors.lastname: McPhail
authors.forename: J
authors.initials: J
authors.lastname: Bostock
authors.forename: G
authors.initials: G
authors.lastname: Carr-White
authors.forename: C A
authors.initials: CA
authors.lastname: Rinaldi
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000628:therapy; D058406:Cardiac Resynchronization Therapy; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012189:Retrospective Studies; D012737:Sex Factors; D016896:Treatment Outcome