Use and safety of heparin-free maintenance hemodialysis in the USA.

BACKGROUND: Although heparin is used to anticoagulate the extracorporeal circuit for most patients on maintenance hemodialysis (HD), some patients undergo heparin-free HD. We describe the determinants of heparin-free HD and its association with adverse outcomes using data from a national dialysis provider merged with Medicare claims.
METHODS: We identified patients aged ≥67 years with no recent history of warfarin use who initiated maintenance HD from 2007 to 2008. We applied the Cox regression to a propensity score-matched cohort to estimate the hazards of all-cause mortality, bleeding (gastrointestinal hemorrhage, hemorrhagic stroke, other hemorrhage), atherothrombosis (ischemic stroke, myocardial infarction) and venous thromboembolism (VTE) (deep vein thrombosis, pulmonary embolism).
RESULTS: Among 12 468 patients, 836 (6.7%) were dialyzed heparin-free. In multivariable-adjusted analyses, a history of gastrointestinal bleeding, hemorrhagic stroke and lower hemoglobin and platelet counts were associated with higher odds of heparin-free HD. Heparin-free HD use also varied as much as 4-fold by facility region. We found no significant association of heparin-free HD with all-cause mortality [hazard ratio (HR) 1.08; 95% confidence interval (CI): 0.94-1.26], bleeding (HR 1.15; 95% CI: 0.83-1.60), atherothrombosis (HR 1.09, 95% CI: 0.90-1.31) or VTE (HR 1.23, 95% CI: 0.93-1.64) compared with HD with heparin.
CONCLUSIONS: Patient markers of increased risk of bleeding and facility region associated with heparin-free HD use. Despite the potential benefits of avoiding heparin use, heparin-free HD was not significantly associated with decreased hazards of death, bleeding or thrombosis, suggesting that it may be no safer than HD with heparin.