A Real-World Comparative Effectiveness Analysis of Thromboprophylactic Use of Enoxaparin Versus Unfractionated Heparin in Abdominal Surgery Patients in a Large U.S. Hospital Database

Introduction: Little is known about outcomes associated with enoxaparin versus unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in abdominal surgery patients in U.S. clinical practice. The purpose of this study was to compare VTE, all-cause mortality, PE-related in-hospital mortality, and hospital costs during abdominal surgery hospitalization and the 90 days post-discharge between patients who received enoxaparin versus UFH prophylaxis. Materials and Methods: Using the Premier Healthcare Database, abdominal surgery patients who received at least 1 day of VTE prophylaxis with enoxaparin or UFH were identified between January 1, 2010 and September 30, 2016. Clinical outcomes were assessed using multivariable logistic regression models and cost outcomes were assessed using generalized linear models. Results: Of 363,669 patients identified, 59% received enoxaparin and 41% UFH. In adjusted analyses, there were statistically significant lower odds of VTE (OR 0.80; 95% CI 0.65-0.97), all-cause mortality (OR 0.67; 95% CI 0.60-0.75), and major bleeding (OR 0.88; 95% CI 0.82-0.94) during the hospitalization for enoxaparin versus UFH, but no differences during the 90-days post-discharge or for PE-related mortality. There was a statistically significant lower total hospital cost with enoxaparin versus UFH during index hospitalization ($8,913 vs $9,017, P < .0001), but not post-discharge ($3,342 vs $3,368, P = .42). Unadjusted rates of heparin-induced thrombocytopenia (index:0.1% vs 0.3%; post-discharge: 0.02% vs 0.06%) were reported for enoxaparin and UFH, respectively. Conclusion: In contemporary U.S. hospital practice, statistically significant lower odds of VTE, all-cause mortality and major bleeding with enoxaparin versus UFH prophylaxis were found during abdominal surgery hospitalizations.

P6425Comparative effectiveness and costs of enoxaparin versus unfractionated heparin in treating acute coronary syndrome

Background/Introduction

Enoxaparin and unfractionated heparin (UFH) are guideline-recommended anticoagulants for patients with acute coronary syndrome (ACS) including unstable angina (UA) and myocardial infarction with (STEMI) or without ST-elevation (NSTEMI). Prior efficacy and safety evidence are mainly from clinical trials. Economic data is lacking.

Purpose

To examine differences in utilization, effectiveness, safety, and costs in treating ACS between enoxaparin and UFH using real-world data.

Methods

Using Premier Healthcare Database from 859 U.S. hospitals, inpatients 18 years or older with a diagnosis of initial episode of ACS between 2010–2016 were analyzed. Outcomes included 30-day risk of non-fatal myocardial infarction (MI), recurrent angina, in-hospital mortality, composite ischemic complication (having MI/recurrent angina/death), major bleeding, and costs. Multivariable regression was used to compare outcomes between enoxaparin and UFH monotherapy.

Results

Among 1,048,053 eligible patients (UA: 219,259; NSTEMI: 582,134; STEMI: 246,660), prevalence of enoxaparin monotherapy was 12.0%, 13.9%, and 5.1% and of UFH monotherapy was 45.1%, 43.1% and 59.8% for UA, NSTEMI, and STEMI patients, respectively. Compared to UFH, enoxaparin was associated with lower odds of MI (Adjusted Odds Ratio [OR]=0.95; 95% Confidence Interval (CI): 0.92, 0.99), recurrent angina (OR=0.88; 95% CI: 0.78, 0.98), in-hospital mortality (OR=0.88; 95% CI: 0.81, 0.95) and composite ischemic complications (OR=0.95; 95% CI: 0.92, 0.98) among NSTEMI patients but not in UA or STEMI patients. Enoxaparin was associated with lower odds of major bleeding in all three patients cohorts (UA: OR=0.77, 95% CI: 0.66, 0.91; NSTEMI: OR=0.68; 95% CI: 0.64, 0.72; STEMI: OR=0.72, 95% CI: 0.63, 0.83). Cost savings per patient during index admission and 30-day follow-up for enoxaparin over UFH was $2,813 for UA, $2,332 for NSTEMI and $2,928 for STEMI patients.

Conclusions

Enoxaparin was associated with lower odds of ischemic complications including death, lower costs and better safety than UFH among NSTEMI patients. Its relative effectiveness varied between patients with different ACS presentations. Improving upstream selection of appropriate anticoagulants in different type of ACS patients has the potential to optimize clinical outcomes and costs.

Acknowledgement/Funding

This study was funded by Sanofi Inc

Dietary n-6 fatty acids inhibit the incorporation of dietary n-3 fatty acids in thrombocyte and serum phospholipids in humans: a controlled dietetic study

The effect of a high dietary intake of n-6 fatty acids (36 g daily) vs a low intake (4-6 g daily) on the incorporation of fatty acids from a dietary supplementation of n-3 fatty acids (6 g daily) was studied for 8 weeks in 15 healthy, normolipaemic volunteers. The importance of a high (43.6) vs a low (20.6) energy percentage from fat was also investigated in the participants on a low n-6 intake. Fatty acid analyses of serum and thrombocyte phospholipids showed a marked increase in docosahexaenoic acid (22:6 (n-3), DHA) and especially eicosapentaenoic acid (20:5 (n-3), EPA) in both the high and low n-6 groups after 14 days, but the changes were significantly greater in the low n-6 diet groups. Changes of the ratio between EPA and arachidonic acid (20:4 (n-6), AA) in phospholipids followed an identical pattern in serum and thrombocytes. This indicates that thrombocytes are influenced by the fatty acid composition in serum. The results showed that incorporation of n-3 fatty acids in phospholipids was reduced by a high intake of dietary n-6 fatty acids in the cells and lipid fractions studied. The observed effect of dietary n-6 fatty acids was independent of the energy percentage provided by dietary fat. In order to obtain an optimal effect of n-3 supplementation, the intake of linoleic acid has to be considered and kept at a low level. The serum content of cholesterol was unaffected, but the concentration of triacylglycerol was reduced during the supplementation period.

Dietary n-3 fatty acids and children with hyperlipidaemia

A review of the literature shows that no studies on children with primary genetic lipid disorders have been published. Case reports are presented indicating that hyperlipidaemias presenting in children--both familial hypercholestrolaemia and disorders with secondary hyperlipidaemia (triglycerides) may benefit of the intake of n-3 fatty acids.