title: Difference in long-term clinical outcome after cardiac resynchronisation therapy between ischaemic and non-ischaemic aetiologies of heart failure.
abstract: OBJECTIVE
  To examine the impact of heart failure (HF) aetiology on long-term outcome after cardiac resynchronisation therapy (CRT).
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  119 patients (44% with ischaemic and 56% non-ischaemic aetiology) who underwent CRT.
  
  
  METHODS
  Clinical follow-up for 39 (24) months.
  
  
  METHODS
  Cardiovascular mortality, HF and cardiovascular hospitalisation were compared by Kaplan-Meier curves between the two groups, followed by Cox regression analysis for prognostic predictor(s).
  
  
  RESULTS
  41 (34%) patients died, in whom cardiovascular causes were identified in 32 (27%) patients. The ischaemic group had a higher cardiovascular mortality (log-rank chi(2) = 4.293, p = 0.038) and cardiovascular hospitalisation (log-rank chi(2) = 5.123, p = 0.024) when compared with the non-ischaemic group, though no difference was found in HF hospitalisation (log-rank chi(2) = 0.019, p = 0.892). At three months, left ventricular reverse remodelling occurred in 52% of the ischaemic group and 55% of the non-ischaemic group (chi(2) = 0.128, p = 0.720). By Cox regression analysis, ischaemic aetiology and absence of reverse remodelling at three months were independent predictors of cardiovascular mortality (HR = 2.698, p = 0.032; HR = 3.541, p = 0.030) and cardiovascular hospitalisation (HR = 1.905, p = 0.015; HR = 2.361, p = 0.004). Furthermore, these two factors had an incremental value in predicting cardiovascular mortality when compared with either alone (left ventricular reverse remodelling, log-rank chi(2) = 10.275 vs 6.311, p = 0.05; Ischaemic aetiology, log-rank chi(2) = 10.275 vs 4.293, p<0.05).
  
  
  CONCLUSIONS
  Ischaemic aetiology of HF is an independent predictor of higher cardiovascular mortality and hospitalisation after CRT. This may implicate the progressive nature of coronary heart disease leading to a worse outcome despite similar short-term benefits of CRT.
authors.affiliation: Li Ka Shing Institute of Health Sciences, Institute of Vascular Medicine, Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: J W-H
authors.initials: JW
authors.lastname: Fung
authors.forename: J Y-S
authors.initials: JY
authors.lastname: Chan
authors.forename: G
authors.initials: G
authors.lastname: Yip
authors.forename: Y-Y
authors.initials: YY
authors.lastname: Lam
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Liang
authors.forename: C-M
authors.initials: CM
authors.lastname: Yu
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D004812:Epidemiologic Methods; D005260:Female; D006333:Heart Failure / Q000209:etiology* / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications* / Q000401:mortality; D016896:Treatment Outcome