title: The safety and efficacy of cardiac contractility modulation in heart failure : A meta-analysis of clinical trials.
abstract: BACKGROUND
  Cardiac contractility modulation (CCM) has developed as a promising treatment device for heart failure (HF). This meta-analysis aimed at systematically reviewing the latest available published trials to provide evidence on the safety and efficacy of CCM in patients with HF.
  
  
  METHODS
  We searched the Cochrane Central Resister of Controlled Trials, PubMed, and EMBASE in May 2016 to identify eligible clinical trials comparing CCM with sham treatment or with usual care. All-cause mortality, all-cause hospitalization, and serious cardiopulmonary adverse effects were considered to be the primary outcomes of interest in evaluating the safety of CCM for patients with HF. Peak oxygen consumption and 6‑min walk tests were performed as the second outcomes of interest to assess efficacy. Risk ratio (RR), standard mean difference (SMD), and 95% confidence intervals (CIs) were calculated.
  
  
  RESULTS
  Four studies enrolling 723 participants were included. Compared with the control arm, CCM did not significantly improve all-cause mortality or all-cause hospitalizations. No differences were observed for adverse effects of CCM, possibly due to the low number of studies. By contrast, CCM significantly improved peak oxygen consumption (standard mean difference 0.233, 95% CI, 0.065-0.401 ml/kg/min, p = 0.006) and the 6‑min walk test distance (standard mean difference 0.924, 95% CI, 0.001-0.334 m, p = 0.049).
  
  
  CONCLUSIONS
  In our meta-analysis of published clinic trials we found that CCM did not lower the risk of severe cardiovascular adverse events; however, it was associated with remarkable improvements in functional cardiopulmonary capacity. Therefore, CCM may serve as an alternative option for patients with advanced HF.
authors.affiliation: Department of Cardiology & Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei, China.|Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China.|Hubei Key Laboratory of Cardiology, 430060, Wuhan, China.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Cardiology & Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei, China.|Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China.|Hubei Key Laboratory of Cardiology, 430060, Wuhan, China.
authors.forename: H J
authors.initials: HJ
authors.lastname: Yang
authors.affiliation: Department of Cardiology & Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei, China.|Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China.|Hubei Key Laboratory of Cardiology, 430060, Wuhan, China.
authors.forename: H Q
authors.initials: HQ
authors.lastname: Ping
authors.affiliation: Department of Cardiology & Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei, China.|Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China.|Hubei Key Laboratory of Cardiology, 430060, Wuhan, China.
authors.forename: S
authors.initials: S
authors.lastname: Qiu
authors.affiliation: Department of Cardiology & Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei, China.|Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China.|Hubei Key Laboratory of Cardiology, 430060, Wuhan, China.
authors.forename: S
authors.initials: S
authors.lastname: Shi
authors.affiliation: Department of Cardiology & Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei, China. yybb112@whu.edu.cn.|Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China. yybb112@whu.edu.cn.|Hubei Key Laboratory of Cardiology, 430060, Wuhan, China. yybb112@whu.edu.cn.
authors.forename: B
authors.initials: B
authors.lastname: Yang
mesh_terms: D058409:Cardiac Resynchronization Therapy Devices; D002423:Cause of Death; D002986:Clinical Trials as Topic; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D012306:Risk; D015996:Survival Rate; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000502:physiology; D000070857:Walk Test
chemical_list: D010100:Oxygen
keywords: Cardiac resynchronization therapy; Heart contractility; Heart failure; Meta-analysis; Ventricular remodeling