title: Comparison of cardiac resynchronization therapy outcomes in patients with New York Heart Association functional class I/II versus III/IV heart failure.
abstract: BACKGROUND
  Several randomized trials have shown that cardiac resynchronization therapy (CRT) benefits New York Heart Association (NYHA) functional class I/II heart failure (HF) patients, but it is unknown if similar outcomes occur in the real-world.
  
  
  RESULTS
  All patients receiving CRT between 2003 and 2008 with ejection fraction (EF) ≤35% and QRS duration ≥120 ms were included. Outcomes assessed were subjective clinical response, echocardiographic response, and survival free of cardiovascular (CV) hospitalization. Baseline demographics in functional class I/II (n = 155) and functional class III/IV (n = 512) were similar, except for differences in age and several comorbidities. Clinical response was similar in both groups. The functional class I/II group had a greater decrease in left ventricular (LV) end-diastolic dimension (P = .031), and trended toward greater improvements in LV end-systolic dimension (P = .056) and EF (P = .059). The functional class I/II group had a better 5-year survival rate (79 vs 54%; P < .0001) and survival free of CV hospitalization (45% vs 26%; P < .0001).
  
  
  CONCLUSIONS
  In this real-world clinical scenario, NYHA functional class I/II CRT patients improved clinical status, and LV function and size as good as or better than those in NYHA functional class III/IV patients. These observations provide further support for the use of CRT in patients with mild symptoms of HF.
authors.affiliation: St Paul Heart Clinic and Allina Heart and Vascular Clinic, St Paul, Minnesota, USA. alan.bank@allina.com
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Bank
authors.forename: Ariel
authors.initials: A
authors.lastname: Rischall
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Gage
authors.forename: Kevin V
authors.initials: KV
authors.lastname: Burns
authors.forename: Spencer H
authors.initials: SH
authors.lastname: Kubo
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*; D020257:Ventricular Remodeling / Q000502:physiology*