Enoxaparin monotherapy more effective and economical than unfractionated heparin monotherapy among inpatients with NSTEMI

Findings from analysis of real-world data from more than 1 million patients from 859 US hospitals.


  • Enoxaparin was associated with a significantly lower risk for ischaemic complications and death than unfractionated heparin (UFH) among inpatients with myocardial infarction (MI) with no ST-segment elevation (NSTEMI) but not in patients with unstable angina (UA) and STEMI.
  • Enoxaparin vs UFH was associated with significantly lower odds of major bleeding and costs among all 3 acute coronary syndrome (ACS) cohorts.


  • Despite proven effectiveness, enoxaparin monotherapy is much less used than UFH monotherapy across all spectrums of ACS.
  • Additional research is needed to better understand the methods for improving the upstream selection of anticoagulants to optimise clinical outcomes.


  • Study evaluated 1,048,053 patients (age, ≥18 years) with an inpatient admission for initial episode of ACS between 2010 and 2016 across 859 US hospitals.
  • Outcomes evaluated: all-cause in-hospital mortality, non-fatal MI, recurrent angina and composite ischaemic complications during any hospital visit within 30 days post-index discharge.
  • Secondary outcomes: prevalence of anticoagulant use, enoxaparinand UFH-related treatment costs, total length of stay and risk for 30-day readmission.
  • Funding: Sanofi Inc.


  • Overall, 20.9%, 55.6% and 23.5% patients were diagnosed with UA, NSTEMI and STEMI, respectively.
  • Among the overall population, 11.4% and 47.4% received enoxaparin and UFH monotherapy, respectively.
  • Among patients with NSTEMI, enoxaparin vs UFH was associated with lower odds of:
    • MI: adjusted OR (aOR), 0.95 (95% CI, 0.92-0.99);
    • recurrent angina: aOR, 0.88 (95% CI, 0.78-0.98);
    • in-hospital mortality: aOR, 0.88 (95% CI, 0.81-0.95); and
    • composite ischaemic complications: aOR, 0.95 (95% CI, 0.92-0.98)
  • Among patients with UA, odds of having composite ischaemic complications (aOR, 1.09; 95% CI, 1.00-1.19) and recurrent angina (aOR, 1.15; 95% CI, 1.03-1.28) were slightly higher in enoxaparin vs UFH group, whereas MI and all-cause in-hospital mortality were comparable.
  • Among patients with STEMI, odds of all mentioned outcomes were lower in enoxaparin group; however, results were not statistically significant.
  • Enoxaparin was associated with lower odds of major bleeding in all 3 cohorts:
    • UA: aOR, 0.77 (95% CI, 0.66-0.91);
    • NSTEMI: aOR, 0.68 (95% CI, 0.64-0.72); and
    • STEMI: aOR, 0.72 (95% CI, 0.63-0.83)
  • The estimated overall cost savings during index admission until 30 days post-index discharge for enoxaparin over UFH cohort were $2972/patient, $2475/patient and $3050/patient for UA, NSTEMI and STEMI cohorts, respectively.
  • 30-day all-cause readmission was lower in enoxaparin vs UFH group for NSTEMI (adjusted mean [aM], 0.95; 95% CI, 0.92-0.98) and STEMI cohorts (aM, 0.92; 95% CI, 0.86-0.98) but higher for UA cohort (aM, 1.12; 95% CI, 1.03-1.22).
  • The total length of hospital stay during the 30-day follow-up was not statistically different in any of the 3 cohorts.


  • Limitations of typical retrospective analysis using a hospital administrative database should be considered.
  • Key outcome variables might have been underestimated.
  • Factors that could influence anticoagulant selection were not captured.

    Rosenthal N, Xiao Z, Kartashov A, Levorsen A, Shah BR. Comparative Effectiveness and Costs of Enoxaparin Monotherapy Versus Unfractionated Heparin Monotherapy in Treating Acute Coronary Syndrome. Am J Cardiovasc Drugs. 2020 Jun 23 [Epub ahead of print]. doi: 10.1007/s40256-020-00419-9. PMID: 32578166.

MAT-BH-2100638/v1/Jul 2021