title: Variability of antithrombotics use in patients with hypoplastic left heart syndrome and its variants following first- and second-stage palliation surgery: a national report using the National Pediatric Cardiology Quality Improvement Collaborative registry.
abstract: Purpose Patients with hypoplastic left heart syndrome and its variants following palliation surgery are at risk for thrombosis. This study examines variability of antithrombotic practice, the incidence of interstage shunt thrombosis, and other adverse events following Stage I and Stage II palliation within the National Pediatric Cardiology Quality Improvement Collaborative registry.
  
  
  METHODS
  We carried out a multicentre, retrospective review using the National Pediatric Cardiology Quality Improvement Collaborative registry including patients from 2008 to 2013 across 52 surgical sites. Antithrombotic medications used at Stage I and Stage II discharge were evaluated. Variability of antithrombotics use at the individual patient level and intersite variability, incidence of shunt thrombosis, and other adverse events such as cardiac arrest, seizure, stroke, and need for cardiac catheterisation intervention in the interstage period were identified. Antithrombotic strategies for hybrid Stage I patients were evaluated but they were excluded from the variability and outcomes analysis.
  
  
  RESULTS
  A total of 932 Stage I and 923 Stage II patients were included in the study: 93.8% of Stage I patients were discharged on aspirin and 4% were discharged on no antithrombotics, and 77% of Stage II patients were discharged on aspirin and 17.5% were discharged on no antithrombotics. Only three patients (0.2%) presented with interstage shunt thrombosis. The majority of patients who died during interstage or required shunt dilation and/or stenting were discharged home on aspirin.
  
  
  CONCLUSIONS
  Aspirin is the most commonly used antithrombotic following Stage I and Stage II palliation. There is more variability in the choice of antithrombotics following Stage II compared with Stage I. The incidence of interstage shunt thrombosis and associated adverse events was rare.
authors.affiliation: 1The Heart Institute,Cincinnati Children's Hospital Medical Centre,Cincinnati, Ohio,United States of America.
authors.forename: Preeti
authors.initials: P
authors.lastname: Ramachandran
authors.affiliation: 2Division of Biostatistics & Epidemiology,Cincinnati Children's Hospital Medical Centre,Cincinnati, Ohio,United States of America.
authors.forename: Eileen
authors.initials: E
authors.lastname: King
authors.affiliation: 3Division of Pharmacy,Cincinnati Children's Hospital Medical Centre,Cincinnati, Ohio,United States of America.
authors.forename: Ashley
authors.identifier: http://orcid.org/0000-0001-5824-8808
authors.initials: A
authors.lastname: Nebbia
authors.affiliation: 1The Heart Institute,Cincinnati Children's Hospital Medical Centre,Cincinnati, Ohio,United States of America.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Beekman
authors.affiliation: 1The Heart Institute,Cincinnati Children's Hospital Medical Centre,Cincinnati, Ohio,United States of America.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Anderson
mesh_terms: D001241:Aspirin / Q000627:therapeutic use*; D006328:Cardiac Catheterization; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000188:drug therapy* / Q000601:surgery*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D058327:Norwood Procedures / Q000009:adverse effects; D010166:Palliative Care; D010351:Patient Discharge; D058996:Quality Improvement; D012042:Registries; D012189:Retrospective Studies; D013927:Thrombosis / Q000188:drug therapy* / Q000209:etiology; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D005343:Fibrinolytic Agents; D001241:Aspirin
keywords: Antithrombotic; conduit; hypoplastic left heart syndrome; interstage period; shunt; shunt thrombosis