title: Effect of cardiac resynchronization therapy in patients with diabetes randomized in EchoCRT.
abstract: As patients with heart failure (HF) and concomitant diabetes carry a poor prognosis, this post-hoc subgroup analysis aimed to compare the outcomes of patients with and without diabetes randomized in the Echocardiography Guided Cardiac Resynchronization Therapy (EchoCRT) study.
  
  
  
  EchoCRT randomized patients with a QRS duration <130 ms and echocardiographic evidence of left ventricular dyssynchrony to CRT turned on (CRT=ON) vs. off (CRT=OFF) following device implantation. At study entry, 328 patients (40.5%) had diabetes. The primary outcome (all-cause death or first hospitalization for worsening HF) occurred more frequently in patients with than without diabetes (32.6% vs. 23%, P = 0.003). A significant treatment interaction was observed for the primary outcome indicating a higher risk for CRT=ON vs. CRT-OFF in patients without [26.5% vs. 19.8%, hazard ratio (HR) 1.58, 95% confidence interval (CI) 1.08-2.31] vs. with diabetes (31.4% vs. 34%; HR 0.86, 95% CI 0.58-1.27; P for interaction 0.041). This effect was mainly driven by a lower rate in HF hospitalizations, but was only of borderline significance after multivariate adjustment (P = 0.063). The most pronounced effect was observed in patients with non-ischaemic cardiomyopathy, where a significantly reduced risk of reaching the primary endpoint for CRT=ON vs. CRT-OFF was observed in patients with (HR 0.27, P = 0.003) vs. patients without diabetes (HR 1.79, P = 0.038; P for interaction 0.005). No treatment interaction by diabetes diagnosis was found for mortality endpoints.
  
  
  
  In EchoCRT, HF patients with a narrow QRS complex and coexisting diabetes demonstrated a signal for less harm caused by CRT compared with patients without diabetes, which was driven by differences in hospitalizations owing to HF.
authors.affiliation: Department of Cardiology, University Heart Centre Zurich, Zurich, Switzerland.
authors.forename: Matthias P
authors.initials: MP
authors.lastname: Nägele
authors.affiliation: Department of Cardiology, University Heart Centre Zurich, Zurich, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Steffel
authors.affiliation: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Michele
authors.initials: M
authors.lastname: Robertson
authors.affiliation: Cardiac Arrhythmia Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jagmeet P
authors.initials: JP
authors.lastname: Singh
authors.affiliation: Department of Cardiology, University Heart Centre Zurich, Zurich, Switzerland.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Flammer
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, the Netherlands.
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.affiliation: Division of Cardiovascular Medicine and Howard Gilman and Ron and Jean Schiavone Institutes, State University of New York Downstate College of Medicine, New York, NY, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Borer
authors.affiliation: University of Bergen, Bergen, Norway.|Stavanger University Hospital, Stavanger, Norway.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Dickstein
authors.affiliation: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Ford
authors.affiliation: University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Gorcsan
authors.affiliation: Nouvelles Cliniques Nantaises, Nantes, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gras
authors.affiliation: Monash Centre of Cardiovascular Research and Education in Therapeutics, Melbourne, VIC, Australia.
authors.forename: Henry
authors.initials: H
authors.lastname: Krum
authors.affiliation: Department of Cardiology and Clinical Institute, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Sogaard
authors.affiliation: Department of Cardiology, University Heart Centre Zurich, Zurich, Switzerland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Holzmeister
authors.affiliation: Division of Cardiovascular Medicine, Ohio State University Medical Center, Columbus, OH, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Abraham
authors.affiliation: Cardiology Department, Thorax Institute, Hospital Clinic, University of Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Brugada
authors.affiliation: Department of Cardiology, University Heart Centre Zurich, Zurich, Switzerland.
authors.forename: Frank
authors.initials: F
authors.lastname: Ruschitzka
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D048909:Diabetes Complications; D003920:Diabetes Mellitus; D004452:Echocardiography; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000628:therapy*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models
keywords: Cardiac resynchronization therapy; Diabetes; Heart failure; Narrow QRS