title: Prophylactic intra-aortic balloon pump in high-risk patients undergoing coronary artery bypass surgery:  a meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  The aim of this study was to assess the efficacy of a prophylactic intra-aortic balloon pump (IABP) in high-risk patients undergoing coronary artery bypass graft surgery.
  
  
  METHODS
  MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar, and reference lists of relevant articles were searched. We included only randomized controlled trials. Assessments for eligibility, relevance, and study validity and data extraction were performed in duplicate using prespecified criteria. Meta-analysis was carried out using fixed-effect and random-effect models.
  
  
  RESULTS
  Seven publications fulfilled our eligibility criteria. There was no important statistical heterogeneity or publication bias among included studies. In total, 177 patients received prophylactic IABP and 168 did not. Overall relative risk (RR) for hospital mortality in patients treated with prophylactic IABP was 0.255 [95% confidence interval (CI), 0.122-0.533; P<0.001; same results for both effect models]. Pooled RR for postoperative low cardiac output syndrome was 0.206 (95% CI, 0.109-0.389; P<0.001) for the fixed-effect model and 0.219 (95% CI, 0.095-0.504; P<0.001) for the random-effect model. Patients treated with prophylactic IABP presented an overall difference in means for length of intensive care unit stay and hospital stay, which was lower than that in the control group (P<0.001 for both effect models). Only 7.4% (13/177) of patients who received prophylactic IABP developed complications at an insertion site, with no IABP-related death.
  
  
  CONCLUSIONS
  This meta-analysis supports the use of prophylactic IABP in high-risk patients to reduce hospital mortality.
authors.affiliation: Division of Cardiovascular Surgery of Pronto Socorro Cardiológico de Pernambuco - PROCAPE, Recife, Pernambuco, Brazil. michel_pompeu@yahoo.com.br
authors.forename: Michel Pompeu B O
authors.initials: MP
authors.lastname: Sá
authors.forename: Paulo E
authors.initials: PE
authors.lastname: Ferraz
authors.forename: Rodrigo R
authors.initials: RR
authors.lastname: Escobar
authors.forename: Wendell N
authors.initials: WN
authors.lastname: Martins
authors.forename: Eliobas O
authors.initials: EO
authors.lastname: Nunes
authors.forename: Frederico P
authors.initials: FP
authors.lastname: Vasconcelos
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Lima
mesh_terms: D002303:Cardiac Output, Low / Q000209:etiology / Q000517:prevention & control; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D007423:Intra-Aortic Balloon Pumping / Q000009:adverse effects / Q000401:mortality; D007902:Length of Stay; D016017:Odds Ratio; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome