title: No impact of endogenous prothrombotic conditions on the risk of central venous line-related thrombotic events in children: results of the KIDCAT study (KIDs with Catheter Associated Thrombosis).
abstract: OBJECTIVE
  Central venous lines (CVLs) are the major exogenous risk factor for deep venous thrombosis (DVT) in children. The study objective was to assess whether endogenous prothrombotic conditions contribute to the risk of CVL-related DVT in children.
  
  
  METHODS
  This was a cohort study of consecutive children with heart disease requiring CVLs for perioperative care. CVLs were inserted percutaneously in the upper venous system and patients received prophylaxis with continuous unfractionated heparin (50 u kg(-1)  d(-1) ). Blood samples to test for prothrombotic conditions were collected prospectively and assayed in a blinded fashion. Outcome assessment was by screening for DVT by venography, venous ultrasound and echocardiography.
  
  
  RESULTS
  The study population consisted of 90 children, median age 2.7 years (0 months-18 years). Prevalence rates of antithrombin deficiency, protein C deficiency, protein S deficiency, heterozygous factor V Leiden, prothrombin G20210A mutation, methylentetrahydrofolate C677TT genotype, hyperhomocysteinemia, lupus anticoagulant, anticardiolipin antibodies and increased levels of lipoprotein (a) were within the range reported for the general population. At least one prothrombotic condition was present in 38% of children and combined abnormalities in 8%. The incidence of DVT was 28% (25/90), and most DVTs were asymptomatic. None of the prothrombotic conditions showed a significant association with DVT. The population attributable risk (i.e. the risk of DVT in the overall population attributable to a specific condition) did not exceed 2.2%.
  
  
  CONCLUSIONS
  Prothrombotic conditions did not have an important impact on the risk of DVT in children with short-term CVLs. The results of the study suggest that screening for prothrombotic conditions is not justified in this setting.
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Thom
authors.forename: C
authors.initials: C
authors.lastname: Male
authors.forename: C
authors.initials: C
authors.lastname: Mannhalter
authors.forename: P
authors.initials: P
authors.lastname: Quehenberger
authors.forename: E
authors.initials: E
authors.lastname: Mlczoch
authors.forename: D
authors.initials: D
authors.lastname: Luckner
authors.forename: M
authors.initials: M
authors.lastname: Marx
authors.forename: A
authors.initials: A
authors.lastname: Hanslik
mesh_terms: D002405:Catheterization, Central Venous / Q000009:adverse effects*; D002648:Child; D004452:Echocardiography; D005165:Factor V / Q000235:genetics; D005260:Female; D005838:Genotype; D006493:Heparin / Q000737:chemistry; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D009154:Mutation; D010690:Phlebography; D015995:Prevalence; D011446:Prospective Studies; D020151:Protein C Deficiency / Q000235:genetics; D018455:Protein S Deficiency / Q000235:genetics; D011516:Prothrombin / Q000235:genetics; D012307:Risk Factors; D019851:Thrombophilia / Q000150:complications* / Q000628:therapy; D013927:Thrombosis / Q000209:etiology* / Q000628:therapy; D016896:Treatment Outcome; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000150:complications* / Q000628:therapy
chemical_list: C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D006493:Heparin; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)
keywords: central venous catheter; children; deep venous thrombosis; risk factors; thrombophilia