title: Comparison of frequency and outcome of major gastrointestinal hemorrhage in patients with atrial fibrillation on versus not receiving warfarin therapy (from the ATRIA and ATRIA-CVRN cohorts).
abstract: To date, there have been few studies evaluating outcomes of patients with atrial fibrillation (AF) who have experienced gastrointestinal (GI) hemorrhages. We examined short- and long-term mortality of major GI hemorrhage in patients with AF on and off warfarin in recent clinical care. We evaluated this association in the large Anticoagulation and Risk Factors in Atrial fibrillation (ATRIA) and ATRIA-Cardiovascular Research Network (CVRN) California community-based cohorts of patients with AF (study years 1996 to 2003 and 2006 to 2009, respectively), where all events were clinician adjudicated. We used proportional hazards regression with propensity score adjustment to estimate the short- (30 days) and long-term (>30 days for 1 year) mortality rate ratio for patients using warfarin compared with those who were not using warfarin at the time of GI hemorrhage. In the 414 ATRIA participants with major GI hemorrhage, 54% were taking warfarin at the time of the hemorrhage; in the 361 ATRIA-CVRN participants with major GI hemorrhage, 58% were taking warfarin. Warfarin use at the time of GI hemorrhage was not associated with 30-day mortality in the ATRIA cohort but was associated with significantly reduced 30-day mortality in the ATRIA-CVRN cohort (adjusted mortality rate ratio [95% confidence interval], ATRIA 0.97 [0.54 to 1.74]; ATRIA-CVRN 0.38 [0.17 to 0.83]). There was a modest suggestion of lower mortality on warfarin after 30 days in both cohorts. In conclusion, our study demonstrates that GI hemorrhages on warfarin are certainly no worse and may be less life threatening than those occurring off warfarin. These findings are in stark contrast to the deleterious effect of warfarin on mortality from intracranial hemorrhage and add another factor favoring anticoagulation in clinical decision making for patients with AF.
authors.affiliation: Division of General Internal Medicine, Massachusetts General Hospital, Boston, Massachusetts; Epidemiology Department, Boston University School of Public Health, Boston, Massachusetts. Electronic address: jashburner@mgh.harvard.edu.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Ashburner
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, California.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Go
authors.affiliation: Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, California.
authors.forename: Kristi
authors.initials: K
authors.lastname: Reynolds
authors.affiliation: Division of General Internal Medicine, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Yuchiao
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Department of Medicine, University of California, San Francisco, San Francisco, California.
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Fang
authors.affiliation: Epidemiology Department, Boston University School of Public Health, Boston, Massachusetts.
authors.forename: Lisa
authors.initials: L
authors.lastname: Fredman
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health and Health Services, The George Washington University, Washington, District of Columbia; Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Katie M
authors.initials: KM
authors.lastname: Applebaum
authors.affiliation: Division of General Internal Medicine, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Singer
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications*; D002140:California / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013923:Thromboembolism / Q000209:etiology* / Q000517:prevention & control; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin