The anti-Xa anticoagulant lowers bleeding and death rates in a routine clinical care setting.
In patients with non–ST-segment elevation myocardial infarction (NSTEMI), the factor Xa inhibitor fondaparinux was noninferior to enoxaparin in reducing ischemic outcomes in the OASIS-5 study. In addition, fondaparinux reduced severe in-hospital bleeding events, leading to both short- and long-term mortality reductions. To see how these trial findings translate to clinical practice, researchers conducted a prospective, multicenter cohort study in Sweden, analyzing data from 40,616 consecutive patients with NSTEMI (mean age, 73 years; 37% women) in the SWEDEHEART registry. Data were from a 4.5-year period spanning the European Society of Cardiology guideline adoption of fondaparinux as the first-line anticoagulant for NSTEMI patients in 2007; the use of fondaparinux increased from 0.7% in 2007 to 84.8% in 2010.
In total, 14,791 patients (36.4%) were treated with fondaparinux and 25,825 (63.6%) with enoxaparin. Rates of in-hospital bleeding were significantly lower with fondaparinux compared with enoxaparin (1.1% vs. 1.8%; adjusted odds ratio, 0.54), as were in-hospital mortality rates (2.7% vs. 4.0%; OR, 0.75). Likewise, major bleeding and mortality rates favored fondaparinux at 30 and 180 days. Rates of recurrent MI and stroke did not differ significantly at 30 or 180 days. Among the 42% of patients who underwent percutaneous coronary intervention (PCI), unfractionated heparin use (77.6 vs. 62.7%) and radial access use (46.3% vs. 36.2%) were more common with fondaparinux than with enoxaparin, and glycoprotein IIb/IIIa use (12.1% vs. 23.5%) was less common. However, the association between anticoagulant treatment and in-hospital outcome was not significantly affected by PCI treatment stratification (P for interaction, 0.27).
Szummer K et al. Association between the use of fondaparinux vs low-molecular-weight heparin and clinical outcomes in patients with non–ST-segment elevation myocardial infarction. JAMA 2015 Feb 17; 313:707