title: Endothelial dysfunction is a marker of systemic response to the cardiac resynchronization therapy in heart failure.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) induces a significant improvement in patients with heart failure (HF), who are often characterized by the presence of endothelial dysfunction (ED) with impaired flow-mediated vasodilation (FMD). We aimed to study the ED in patients with HF candidates to CRT with defibrillator (CRT-D).
  
  
  RESULTS
  We studied 57 consecutive patients affected by HF and undergoing CRT-D. At the baseline we recorded a high prevalence of ED (64.9%) with impaired FMD (4.1 ± 3.8%). After 12 months of CRT, we reported a marked increase of the mean FMD (8.8 ± 4.8% vs 4.1 ± 3.8%; P < .05) along with significant improvement of left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), New York Heart Association (NYHA) functional class, and 6-minute walk test (6MWT); 42 patients (73.7%) were classified as responders according to standard criteria. FMD was related to LVEF (r = 0.169; P < .05), LVESV (r = -0.169; P < .05), NYHA functional class (r = -0.27; P < .051), and 6MWT (r = 0.360; P < .01).
  
  
  CONCLUSIONS
  ED is not an independent predictor of CRT response, but it is able to intercept the systemic effects of CRT and is an affordable marker of response to CRT, especially in patients unable to perform the 6MWT.
authors.affiliation: Department of Cardiology, University Hospital of Tor Vergata, Rome, Italy. lsantini@alice.it
authors.forename: Luca
authors.initials: L
authors.lastname: Santini
authors.forename: Ambrogio
authors.initials: A
authors.lastname: Capria
authors.forename: Arianna
authors.initials: A
authors.lastname: Di Molfetta
authors.forename: Karim
authors.initials: K
authors.lastname: Mahfouz
authors.forename: Germana
authors.initials: G
authors.lastname: Panattoni
authors.forename: Valentina
authors.initials: V
authors.lastname: Minni
authors.forename: Domenico
authors.initials: D
authors.lastname: Sergi
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Forleo
authors.forename: Francesco
authors.initials: F
authors.lastname: Romeo
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D058406:Cardiac Resynchronization Therapy; D002306:Cardiac Volume / Q000502:physiology; D017147:Defibrillators, Implantable; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D013318:Stroke Volume / Q000502:physiology; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology