title: Cardiac resynchronization therapy reduces the risk of cardiac events in patients with diabetes enrolled in the multicenter automatic defibrillator implantation trial with cardiac resynchronization therapy (MADIT-CRT).
abstract: BACKGROUND
  Data are limited regarding whether the presence of diabetes mellitus (DM) influences the benefit of cardiac resynchronization with defibrillator therapy (CRT-D) in heart failure (HF) patients.
  
  
  RESULTS
  The effect of CRT-D was evaluated in 1817 patients who were enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT). Patients were minimally symptomatic (New York Heart Association class I or II), with ejection fraction ≤0.30 and QRS ≥130 ms. We used Cox regression to determine hazard ratio (HR) of CRT-D versus implantable cardioverter-defibrillator (ICD) therapy for the risk of HF event or death, whichever came first (MADIT-CRT primary end point), in DM (n=552) and non-DM (n=1265) patients. Compared with the non-DM patients, those with DM had more coronary risk factors. During an average follow-up of 2.4 years, DM patients had significantly more primary end point events than non-DM patients (26.6% versus 18%, P<0.001). CRT-D was associated with a significant reduction in risk of primary end point in both DM (HR=0.56, P<0.001) and non-DM patients (HR=0.67, P=0.003). Compared with non-DM patients, CRT-D:ICD HRs in DM patients were lower in the total population, and in subgroups with ischemic cardiomyopathy (0.63 versus 0.64), nonischemic cardiomyopathy (0.39 versus 0.73), and left bundle-branch block (0.36 versus 0.50). There were no significant differences in ventricular remodeling, arrhythmia events, or device-related complications between DM and non-DM patients.
  
  
  CONCLUSIONS
  Patients with diabetes, left ventricular dysfunction, mildly symptomatic HF, and wide QRS complex derive similar benefit from CRT-D compared with patients without diabetes.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.
authors.affiliation: Department of Cardiovascular Medicine, Lahey Clinic Medical Center, Burlington, MA 01805, USA. david.t.martin@lahey.org
authors.forename: David T
authors.initials: DT
authors.lastname: Martin
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Richard W
authors.initials: RW
authors.lastname: Nesto
authors.forename: Martin K
authors.initials: MK
authors.lastname: Rutter
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D017147:Defibrillators, Implantable; D003920:Diabetes Mellitus; D005260:Female; D006327:Heart Block / Q000628:therapy*; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D008297:Male; D016016:Proportional Hazards Models; D012307:Risk Factors