title: Blood transfusion after percutaneous coronary intervention and risk of subsequent adverse outcomes: a systematic review and meta-analysis.
abstract: OBJECTIVE
  This study sought to define the prevalence and prognostic impact of blood transfusions in contemporary percutaneous coronary intervention (PCI) practice.
  
  
  BACKGROUND
  Although the presence of anemia is associated with adverse outcomes in patients undergoing PCI, the optimal use of blood products in patients undergoing PCI remains controversial.
  
  
  METHODS
  A search of EMBASE and MEDLINE was conducted to identify PCI studies that evaluated blood transfusions and their association with major adverse cardiac events (MACE) and mortality. Two independent reviewers screened the studies for inclusion, and data were extracted from relevant studies. Random effects meta-analysis was used to estimate the risk of adverse outcomes with blood transfusions. Statistical heterogeneity was assessed by considering the I(2) statistic.
  
  
  RESULTS
  Nineteen studies that included 2,258,711 patients with more than 54,000 transfusion events were identified (prevalence of blood transfusion 2.3%). Crude mortality rate was 6,435 of 50,979 (12.6%, 8 studies) in patients who received a blood transfusion and 27,061 of 2,266,111 (1.2%, 8 studies) in the remaining patients. Crude MACE rates were 17.4% (8,439 of 48,518) in patients who had a blood transfusion and 3.1% (68,062 of 2,212,730) in the remaining cohort. Meta-analysis demonstrated that blood transfusion was independently associated with an increase in mortality (odds ratio: 3.02, 95% confidence interval: 2.16 to 4.21, I(2) = 91%) and MACE (odds ratio: 3.15, 95% confidence interval: 2.59 to 3.82, I(2) = 81%). Similar observations were recorded in studies that adjusted for baseline hematocrit, anemia, and bleeding.
  
  
  CONCLUSIONS
  Blood transfusion is independently associated with increased risk of mortality and MACE events. Clinicians should minimize the risk for periprocedural transfusion by using available bleeding-avoidance strategies and avoiding liberal transfusion practices.
authors.affiliation: Cardiovascular Institute, University of Manchester, Manchester, United Kingdom.
authors.forename: Chun Shing
authors.initials: CS
authors.lastname: Kwok
authors.affiliation: The Duke Clinical Research Institute, Durham, North Carolina.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Sherwood
authors.affiliation: Department of Gastroenterology, Royal Bolton Hospital, Farnworth, United Kingdom.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Watson
authors.affiliation: Department of Gastroenterology, Royal Bolton Hospital, Farnworth, United Kingdom.
authors.forename: Samina B
authors.initials: SB
authors.lastname: Nasir
authors.affiliation: Institute of Population Health, University of Manchester, United Kingdom.
authors.forename: Matt
authors.initials: M
authors.lastname: Sperrin
authors.affiliation: Department of Cardiology, University Hospital of North Staffordshire, Stoke-on-Trent, United Kingdom.
authors.forename: Jim
authors.initials: J
authors.lastname: Nolan
authors.affiliation: Department of Cardiology, University Hospital of Wales, Cardiff, United Kingdom.
authors.forename: Tim
authors.initials: T
authors.lastname: Kinnaird
authors.affiliation: Department of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Songsak
authors.initials: S
authors.lastname: Kiatchoosakun
authors.affiliation: Department of Cardiology, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom.
authors.forename: Peter F
authors.initials: PF
authors.lastname: Ludman
authors.affiliation: Department of Cardiology, The James Cook University Hospital, Middlesbrough, United Kingdom.
authors.forename: Mark A
authors.initials: MA
authors.lastname: de Belder
authors.affiliation: The Duke Clinical Research Institute, Durham, North Carolina.
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Rao
authors.affiliation: Cardiovascular Institute, University of Manchester, Manchester, United Kingdom. Electronic address: mamasmamas1@yahoo.co.uk.
authors.forename: Mamas A
authors.initials: MA
authors.lastname: Mamas
mesh_terms: D000740:Anemia / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D000925:Anticoagulants / Q000009:adverse effects; D001803:Blood Transfusion / Q000401:mortality; D016009:Chi-Square Distribution; D006331:Heart Diseases / Q000209:etiology / Q000401:mortality; D006470:Hemorrhage / Q000139:chemically induced / Q000401:mortality / Q000628:therapy*; D006801:Humans; D016017:Odds Ratio; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects* / Q000401:mortality; D018570:Risk Assessment; D012307:Risk Factors; D065227:Transfusion Reaction; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants
keywords: blood transfusion; cardiovascular events; meta-analysis; mortality