Aging and heparin-related bleeding.

BACKGROUND

Many studies have suggested that elderly patients are at increased risk of bleeding during heparin therapy.

OBJECTIVE

To establish whether the risk of bleeding in the elderly results from concomitant risk factors or is associated with the aging process itself.

METHODS

One hundred ninety-nine patients who presented with proximal deep vein thrombosis were treated with a standard intravenous heparin protocol in a double-blind, randomized, prospective study. Bleeding complications were monitored. Activated partial thromboplastin times and heparin levels were assessed 4 to 6 hours after a standard intravenous heparin bolus and infusion. Heparin doses and heparin levels were also assessed after stable therapeutic heparin infusion rates were established.

RESULTS

There was an increase in total and major bleeding complications with aging (P < .05) that was not accounted for by standard risk factors for bleeding. Aging was associated with an increase in heparin levels (r = .239, P = .003) and a tendency for an increase in activated partial thromboplastin time (r = .134, P = .07) after standard heparin doses. Aging was also associated with lower heparin dose requirements (r = .267, P = .003) after therapeutic activated partial thromboplastin times were achieved.

CONCLUSIONS

Aging is a risk for heparin-related bleeding that may be explicable by age-related changes in the pharmacologic characteristics of heparin.