title: Thromboembolic events among patients with hepatitis C virus infection and cirrhosis: a matched-cohort study.
abstract: BACKGROUND
  Portal vein thrombosis is a known risk among patients with cirrhosis, but the incidence of other thromboembolic events among patients with liver disease is inadequately delineated. This study examined the incidence of venous and arterial thromboembolic events in patients with cirrhosis and hepatitis C virus (HCV) infection and matched comparators.
  
  
  METHODS
  Patients diagnosed with HCV or cirrhosis of various etiologies were identified from a large medical claims database and matched by age and sex to comparator cohorts. New-onset diagnoses of venous and arterial thromboembolic events were determined. The incidence rate of each event was calculated and rate ratios computed using Poisson regression models, adjusting for baseline factors.
  
  
  RESULTS
  The study included 22,733 HCV-infected patients and 68,198 comparators, and 15,158 cirrhosis patients and 45,473 comparators. The incidence of any thromboembolic event was 233.4 events per 10,000 person-years for the HCV cohort and 138.5 per 10,000 person-years for the comparators; the adjusted incidence rate ratio for any thromboembolic event was 1.62 (95% confidence interval [CI]: 1.48-1.77). For the cirrhosis patients and comparators, the crude rates of any thromboembolic event were 561.1 and 249.7 per 10,000 person-years, respectively. The adjusted incidence rate ratio was 2.28 (95% CI: 2.11-2.47). Arterial events, especially unstable angina and transient ischemic attack, were the most frequent events seen in both the HCV and cirrhosis cohorts, but venous events, especially portal vein thrombosis, showed a more pronounced elevation in patients with liver disease.
  
  
  CONCLUSIONS
  Patients with HCV and cirrhosis of various etiologies are at increased risk of several types of thromboembolic events. Physicians should consider this increased risk when managing patients with liver disease.
authors.affiliation: Optum, 315 E. Eisenhower Parkway, Suite 305, Ann Arbor, MI, 48108, USA.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Enger
authors.forename: Ulla M
authors.initials: UM
authors.lastname: Forssen
authors.forename: Dimitri
authors.initials: D
authors.lastname: Bennett
authors.forename: Dickens
authors.initials: D
authors.lastname: Theodore
authors.forename: Sumitra
authors.initials: S
authors.lastname: Shantakumar
authors.forename: Andrew
authors.initials: A
authors.lastname: McAfee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006526:Hepatitis C / Q000150:complications*; D006801:Humans; D015994:Incidence; D008103:Liver Cirrhosis / Q000150:complications*; D008297:Male; D008875:Middle Aged; D013923:Thromboembolism / Q000150:complications*; D055815:Young Adult