AGING AND HEPARIN-RELATED BLEEDING

Background: Many studies have suggested that elderly patients are at i ncreased risk of bleeding during heparin therapy. Objective: To establ ish whether the risk of bleeding in the elderly results from concomita nt risk factors or is associated with the aging process itself. Method s: One hundred ninety-nine patients who presented with proximal deep v ein thrombosis were treated with a standard intravenous heparin protoc ol in a double-blind, randomized, prospective study. Bleeding complica tions were monitored. Activated partial thromboplastin times and hepar in levels were assessed 4 to 6 hours after a standard intravenous hepa rin bolus and infusion. Heparin doses and heparin levels were also ass essed after stable therapeutic heparin infusion rates were established . Results: There was an increase in total and major bleeding complicat ions with aging (P<.05) that was not accounted for by standard risk fa ctors for bleeding. Aging was associated with an increase in heparin l evels (r=.239, P=.003) and a tendency for an increase in activated par tial thromboplastin time (r=.134, P=.07) after standard heparin doses. Aging was also associated with lower heparin dose requirements (r=-.2 67, P=.003) after therapeutic activated partial thromboplastin times w ere achieved. Conclusion: Aging is a risk for heparin-related bleeding that may be explicable by age-related changes in the pharmacologic ch aracteristics of heparin.