No difference in bleeding risk between subcutaneous enoxaparin and heparin for thromboprophylaxis in end-stage renal disease

Enoxaparin, a low-molecular-weight form of heparin, is not approved for use in dialysis patients in the United States, because it is eliminated through the kidneys and could therefore accumulate and cause inadvertent bleeding. Accordingly, it is unknown if enoxaparin is as safe to prescribe as subcutaneous heparin for thromboprophylaxis in patients with chronic renal failure. Here we conducted a retrospective comparative effectiveness study in a large population of chronic maintenance dialysis patients initiated with subcutaneous injections of enoxaparin or heparin for thromboprophylaxis. The primary study end point was hospitalization or death related to bleeding, with a secondary end point of venous thromboembolism. Among 7721 dialysis patients started on subcutaneous enoxaparin or heparin at doses for thromboprophylaxis, the crude rate for bleeding requiring hospitalization or resulting in death was 15.2 (95% confidence interval (CI) 12.7-18.2) events per 100 patient-years in the enoxaparin group, which did not differ from the heparin group in which the crude rate was 16.2 (95% CI 14.0-18.7) events per 100 patient-years. In risk factor-adjusted Poisson models, enoxaparin was not associated with more bleeding in comparison to heparin (risk ratio, 0.98; 95% CI 0.78-1.23). The risk of venous thromboembolism was not associatively worse with enoxaparin (risk ratio, 0.77; 95% CI 0.49-1.22). Thus, in dialysis patients, daily enoxaparin for thromboprophylaxis was not associated with increased serious bleeding or less effective compared to subcutaneous heparin.