title: Anticoagulant and antiplatelet usage associates with mortality among hemodialysis patients.
abstract: Many prescribe anticoagulants and antiplatelet medications to prevent thromboembolic events and access thrombosis in dialysis patients despite limited evidence of their efficacy in this population. This retrospective cohort study examined whether use of warfarin, clopidogrel, and/or aspirin affected survival in 41,425 incident hemodialysis patients during 5 yr of follow-up. The prescription frequencies for warfarin, clopidogrel, and aspirin were 8.3, 10.0, and 30.4%, respectively, during the first 90 d of initiating chronic hemodialysis. Compared with the 24,740 patients receiving none of these medications, Cox proportional hazards analysis suggested that exposure to these medications was associated with increased risk for mortality (warfarin hazard ratio [HR] 1.27 [95% confidence interval (CI) 1.18 to 1.37]; clopidogrel HR 1.24 [95% CI 1.13 to 1.35]; and aspirin HR 1.06 [95% CI 1.01 to 1.11]). The increased mortality associated with warfarin or clopidogrel use remained in stratified analyses. A covariate- and propensity-adjusted time-varying analysis, which accounted for longitudinal changes in prescription, produced similar results. In addition, matching for treatment facility and attending physician revealed similar associations between prescription and mortality. We conclude that warfarin, aspirin, or clopidogrel prescription is associated with higher mortality among hemodialysis patients. Given the possibility of confounding by indication, randomized trials are needed to determine definitively the risk and benefit of these medications.
authors.affiliation: Fresenius Medical Care NA, Waltham, Massachusetts, USA. kevin.chan@fmc-na.com
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Chan
authors.forename: J Michael
authors.initials: JM
authors.lastname: Lazarus
authors.forename: Ravi
authors.initials: R
authors.lastname: Thadhani
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Hakim
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects*; D000077144:Clopidogrel; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D016016:Proportional Hazards Models; D044469:Racial Groups; D006435:Renal Dialysis / Q000401:mortality*; D012189:Retrospective Studies; D018570:Risk Assessment; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000633:toxicity; D014859:Warfarin / Q000633:toxicity*
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D000077144:Clopidogrel; D013988:Ticlopidine