Enoxaparin dosing and associated risk of in-hospital bleeding and death in patients with non ST-segment elevation acute coronary syndromes.

BACKGROUND

The efficacy of enoxaparin sodium in non-ST-segment elevation acute coronary syndromes is well established; however, concerns remain regarding bleeding risk. The extent to which bleeding risk is attributable to excess dosing of enoxaparin is unclear.

METHODS

Using data from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) National Quality Improvement Initiative, we determined the frequency of administration of excess (>10 mg above the recommended dose), lower-than-recommended (>10 mg below the recommended dose), and recommended doses of enoxaparin. We also determined unadjusted and adjusted risks of in-hospital major bleeding and death associated with excess and lower-than-recommended doses of enoxaparin.

RESULTS

Of 10 687 patients, 2002 (18.7%) received an excess dose and 3116 (29.2%) received a lower-than-recommended dose of enoxaparin. Patients receiving excess doses were older (median age, 78 vs 66 years), smaller (median body mass index [calculated as weight in kilograms divided by height in meters squared], 26.2 vs 27.8), and more likely to be female (59.5% vs 38.2%) than patients receiving recommended doses (P < .001 for all). After adjustment for baseline characteristics, an excess dose was significantly associated with major bleeding (odds ratio, 1.43; 95% confidence interval [CI], 1.18-1.75) and death (odds ratio, 1.35; 95% CI, 1.03-1.77) compared with a recommended dose. A lower-than-recommended dose was not associated with major bleeding (odds ratio, 1.01; 95% CI, 0.84-1.21), but there was a trend toward higher mortality (odds ratio, 1.25; 95% CI, 0.93-1.68).

CONCLUSIONS

Almost half the patients treated with enoxaparin did not receive a recommended dose and had worse outcomes, especially those receiving an excess dose. Improved adherence to the recommended dose could substantially improve the safety profile of enoxaparin.