title: Impact of transfusion on stroke after cardiovascular interventions: Meta-analysis of comparative studies.
abstract: To evaluate the impact of transfusion on the development of stroke after cardiovascular interventions.
  
  
  
  A literature search was performed to identify comparative studies on the impact of blood transfusion on the occurrence of stroke after adult cardiac surgery and interventional cardiology procedures.
  
  
  
  Twenty-four studies compared the outcome of 80 283 patients who received and 2 260 709 patients who did not receive blood transfusion after cardiovascular interventions. Pooled analysis showed that transfused patients had a higher risk of postoperative stroke (2.1% vs 0.9%; P < .001; risk ratio [RR], 2.563; 95% confidence interval [CI], 1.615-4.069; I2= 94%) compared with patient who did not receive blood transfusion. The leave-one-out analysis confirmed the consistency of the overall series (RR ranged from 2.367 [95% CI, 1.978-2.834] to 2.676 [95% CI, 1.679-4.265]). Transfusion was associated with increased risk of stroke after either interventional cardiology interventions (3.2% vs 1.1%; RR, 3.325; 95% CI, 1.579-7.004) or cardiac surgery (1.9% vs 0.8%; RR, 2.260; 95% CI, 1.845-2.769). Generic inverse variance analysis of 11 studies reporting adjusted odds ratios for baseline characteristics showed that transfusion after cardiovascular interventions was an independent predictor of stroke (RR, 1.53; 95% CI, 1.10-2.14; I2= 0%).
  
  
  
  Blood transfusion is associated with a significantly increased risk of postoperative stroke in patients undergoing cardiovascular interventions.
  
  
  
  The present meta-analysis is registered in PROSPERO, code CRD42016046426.
authors.affiliation: Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Debora
authors.initials: D
authors.lastname: Brascia
authors.affiliation: Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Noemi
authors.initials: N
authors.lastname: Garcia-Medina
authors.affiliation: Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Eeva-Maija
authors.initials: EM
authors.lastname: Kinnunen
authors.affiliation: Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Tauriainen
authors.affiliation: Heart Center, Turku University Hospital, Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Airaksinen
authors.affiliation: Department of Surgery, Oulu University Hospital, Oulu, Finland. Electronic address: faustobiancari@yahoo.it.
authors.forename: Fausto
authors.initials: F
authors.lastname: Biancari
mesh_terms: D006348:Cardiac Surgical Procedures; D006801:Humans; D016017:Odds Ratio; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D065227:Transfusion Reaction
keywords: Aortic valve replacement; Blood transfusion; Cardiac surgery; Coronary artery bypass grafting; Percutaneous coronary intervention; Stroke