title: Anticoagulation practices and the prevalence of major bleeding, thromboembolic events, and mortality in venoarterial extracorporeal membrane oxygenation: A systematic review and meta-analysis.
abstract: The purpose was to evaluate the safety of anticoagulation in venoarterial extracorporeal membrane oxygenation (VA-ECMO).
  
  
  
  We performed a systematic review and meta-analysis using multiple electronic databases. Studies were from 1977 to September 27, 2016. We evaluated the effect of anticoagulation in VA-ECMO on outcomes including major bleeding, thromboembolic events, and in-hospital mortality using a random effects model meta-analysis.
  
  
  
  Twenty-six studies (1496 patients) were included. Ten studies only had patients with postcardiotomy shock, 4 studies only included extracorporeal cardiopulmonary resuscitation patients, and 10 studies had a mixture of patients. Most studies (n=17) were low quality with a Newcastle-Ottawa Scale score ≤5. The summary prevalence of major bleeding was 27% (95% confidence interval [CI], 18%-35%), with considerable between-study heterogeneity (I2=91%). Major bleeding requiring reoperation was the most common bleeding event. The summary prevalence of thromboembolic events was 8% (95% CI, 4%-13%; I2=83%). Limb ischemia, circuit-related clotting, and stroke were the most commonly reported events. The summary prevalence for in-hospital mortality was 59% (95% CI, 52%-67%; I2=78%).
  
  
  
  The optimal targets and strategies for anticoagulation in VA-ECMO are unclear. Evaluation of major bleeding and thromboembolic events is limited by study quality and between-study heterogeneity. Clinical trials are needed to investigate the optimal anticoagulation strategy.
authors.affiliation: Department of Critical Care, Regina General Hospital, Regina, Saskatchewan, Canada; Department of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: eric.julian.sy@gmail.com.
authors.forename: Eric
authors.initials: E
authors.lastname: Sy
authors.affiliation: Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Sklar
authors.affiliation: Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Laurence
authors.initials: L
authors.lastname: Lequier
authors.affiliation: Critical Care Medicine, University Health Network and Mount Sinai Hospitals, Toronto, Ontario; Interdepartmental Division of Critical Care, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada.
authors.forename: Eddy
authors.initials: E
authors.lastname: Fan
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Division of Critical Care Medicine, Department of Medicine, University of British Columbia, Vancouver General Hospital, Vancouver, BC, Canada.
authors.forename: Hussein D
authors.initials: HD
authors.lastname: Kanji
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000502:physiology; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects* / Q000401:mortality; D005260:Female; D006470:Hemorrhage / Q000209:etiology* / Q000401:mortality; D017052:Hospital Mortality; D006801:Humans; D010818:Practice Patterns, Physicians'; D015995:Prevalence; D013923:Thromboembolism / Q000209:etiology* / Q000401:mortality / Q000517:prevention & control
chemical_list: D000925:Anticoagulants
keywords: Anticoagulants; Extracorporeal membrane oxygenation; Heparin; Meta-analysis; Systematic review