title: Long-term independent predictors of positive response to cardiac resynchronization therapy.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) is currently considered an important breakthrough in the treatment of selected patients with refractory heart failure. However, long-term predictors of mortality, morbidity and time to recovery of ventricular function for those patients who respond positively to CRT remain poorly investigated.
  
  
  METHODS
  This is a retrospective follow-up study involving one hospital. Between August 2004 and October 2008, 211 consecutive patients with refractory heart failure received a CRT device in the Cardiology Division of Ospedale Civile Maggiore in Verona. The clinical characteristics studied were age, sex, heart rhythm, left ventricular end-systolic volume/body surface area (LVESV/BSA), left ventricular ejection fraction, QRS duration, type of bundle-branch block, cause, New York Heart Failure Association functional class, pharmacological therapy and lead position. The objective of this study was to evaluate the effect of several baseline characteristics on long-term prognosis in heart failure patients treated with CRT.
  
  
  RESULTS
  Nonischemic cause, left bundle-branch block and a basal LVESV/BSA of 106 ml/m or less were the only independent predictors of a positive response to CRT (P < 0.005). Additionally, a reduction in LVESV/BSA after CRT was associated both with increased survival and reduced rehospitalization for heart failure (P < 0.005).
  
  
  CONCLUSIONS
  A better selection of patients on the basis of cause, type of bundle-branch block and basal LVESV/BSA can increase the number of patients that would benefit from CRT.
authors.affiliation: Division of Cardiology, Department of Biomedical and Surgical Sciences, University of Verona, Verona, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Toniolo
authors.forename: Gabriele
authors.initials: G
authors.lastname: Zanotto
authors.forename: Andrea
authors.initials: A
authors.lastname: Rossi
authors.forename: Luca
authors.initials: L
authors.lastname: Tomasi
authors.forename: Maria A
authors.initials: MA
authors.lastname: Prioli
authors.forename: Corrado
authors.initials: C
authors.lastname: Vassanelli
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging / Q000628:therapy; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications; D018579:Patient Selection; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D014463:Ultrasonography