title: Safety of vitamin K antagonist treatment for splanchnic vein thrombosis: a multicenter cohort study.
abstract: BACKGROUND
  The treatment of splanchnic vein thrombosis (SVT) is challenging, due to the increased risk of bleeding and potentially life-threatening complications. Current recommendations are based on evidence from the treatment of venous thrombosis in usual sites, but small observational studies in SVT population suggest that the bleeding risk may offset the benefit of anticoagulant treatment in this setting. The aim of this study was to evaluate the safety of vitamin K antagonists (VKAs) in SVT patients.
  
  
  METHODS
  We retrospectively included SVT patients treated with VKAs followed by 37 Italian anticoagulation clinics, until June 2013. The primary outcome was the incidence of major bleeding (MB), according to the ISTH definition, during VKA treatment. Vascular events, including both arterial and venous thrombosis, and mortality were also documented.
  
  
  RESULTS
  Three hundred and seventy-five patients were included (median age 53 years; 54.7% males). During a median VKA treatment duration of 1.98 years, 15 MB events occurred, corresponding to an incidence rate of 1.24 (95% confidence interval [CI], 0.75-2.06) per 100 patient-years. Gastrointestinal bleeding represented 40% of all MB events. At multivariate analysis, the presence of esophageal varices emerged as independent predictor of MB (hazard ratio 5.4; 95% CI, 1.4-21.1). The incidence rate of vascular events on treatment was 1.37 (95% CI, 0.84-2.23) per 100 patient-years and the mortality rate was 0.83 (95% CI, 0.44-1.54) per 100 patient-years.
  
  
  CONCLUSIONS
  Selected SVT patients followed by anticoagulation clinics for the management of VKA treatment show a low rate of major bleeding and vascular events.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Insubria, Varese, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Riva
authors.affiliation: Department of Clinical and Experimental Medicine, University of Insubria, Varese, Italy.
authors.forename: W
authors.initials: W
authors.lastname: Ageno
authors.affiliation: Department of Heart and Vessels, Thrombosis Centre, AOU-Careggi, Florence, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Poli
authors.affiliation: Haemostasis and Thrombosis Centre, AO Istituti Ospitalieri, Cremona, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Testa
authors.affiliation: Division of Hematology, Haemostasis and Thrombosis Center, AOU Ospedali Riuniti Umberto I, G.M. Lancisi, G. Salesi, Ancona, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Rupoli
authors.affiliation: Hemostasis and Thrombosis Unit, Hemophilia Center, Azienda Ospedaliera "Pugliese-Ciaccio", Catanzaro, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Santoro
authors.affiliation: Department of Immunohematology and Transfusion Medicine, Hospital Papa Giovanni XXIII, Bergamo, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Lerede
authors.affiliation: Department of Internal Medicine, Ospedale S. Martino, Genoa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Piana
authors.affiliation: Department of Hematology and Transplant Unit, AO San Gerardo, Monza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Carpenedo
authors.affiliation: Department of Internal Medicine, Arcispedale Santa Maria Nuova, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Nicolini
authors.affiliation: Dipartimento Emergenza-Urgenza e Area Medica e Specialistica, AOU Parma, Parma, Italy.
authors.forename: P M
authors.initials: PM
authors.lastname: Ferrini
authors.affiliation: Department of Hematology, Hemostasis and Thrombosis Center, S. Bortolo Hospital, Vicenza, Italy.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-0119-5204
authors.initials: A
authors.lastname: Tosetto
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D016009:Chi-Square Distribution; D004932:Esophageal and Gastric Varices / Q000401:mortality; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced / Q000401:mortality; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D061214:Patient Safety; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013152:Splanchnic Circulation; D013997:Time Factors; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D014812:Vitamin K / Q000037:antagonists & inhibitors*; D055815:Young Adult
chemical_list: D000925:Anticoagulants; D014812:Vitamin K
keywords: antivitamins K; bleeding; cohort study; deep vein thrombosis; portal vein