title: Does Enhanced External Counterpulsation (EECP) Significantly Affect Myocardial Perfusion?: A Systematic Review & Meta-Analysis.
abstract: BACKGROUND
  Enhanced external counterpulsation (EECP) is currently applied for treating coronary artery disease (CAD) patients. However, the mechanism(s) by which EECP ameliorates angina pectoris and long-term left ventricular function remain largely unknown. The aim of this study will be to assess whether EECP significantly affects myocardial perfusion in CAD patients through a systematic review and meta-analysis of the available literature.
  
  
  METHODS
  MEDLINE, EMBASE, and Cochrane CENTRAL databases were searched for prospective studies on CAD patients that underwent EECP and reported myocardial perfusion data pre- and post-EECP. The impact of EECP was assessed based on the weighted mean difference (WMD) in myocardial perfusion from pre-EECP to post-EECP. Statistical heterogeneity was assessed by the I2 index. Publication bias was assessed through visual inspection of the funnel plot as well as Begg's and Egger's testing.
  
  
  RESULTS
  Standard EECP therapy (i.e., 35-36 one-hour sessions within a seven-week period) significantly increased myocardial perfusion in CAD patients (pooled WMD: -0.19, 95% CI: -0.38 to 0.00, p = 0.049). A random effects analysis was applied on account of significant heterogeneity (I2 = 89.1%, p = 0.000). There was no evidence of significant publication bias (Begg's p = 0.091; Egger's p = 0.282).
  
  
  CONCLUSIONS
  Standard EECP therapy significantly increases myocardial perfusion in CAD patients. This study's findings support the continued use of standard EECP therapy in CAD patients and provides one putative physiological mechanism to help explain the improvements in angina pectoris and long-term left ventricular function observed in CAD patients after EECP therapy.
authors.affiliation: Department of Rehabilitation Medicine, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Qin
authors.affiliation: Department of Rehabilitation Medicine, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Yanye
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Rehabilitation Medicine, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Dandong
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Rehabilitation Medicine, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Lehua
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Rehabilitation Medicine, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Rongzhong
authors.initials: R
authors.lastname: Huang
mesh_terms: D003324:Coronary Artery Disease / Q000503:physiopathology* / Q000628:therapy*; D015908:Counterpulsation / Q000379:methods*; D006801:Humans; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000628:therapy*; D011446:Prospective Studies