Although anticoagulation with unfractionated heparin (UFH) is commonly used during intra-aortic balloon pump (IABP) counterpulsation to prevent thromboembolic events, no data or guidelines exist to support this strategy, especially in the setting of acute myocardial infarction (AMI). This study sought to compare the short-term outcome of UFH vs fondaparinux in AMI patients who underwent successful percutaneous coronary intervention (PCI) and IABP insertion.

The anticoagulation therapy of revascularised AMI patients who received IABP counterpulsation and admitted to a tertiary hospital in the last decade was retrospectively evaluated. The primary outcome was the occurrence of all-cause mortality, stroke or transient ischaemic attack, reinfarction, unplanned revascularisation, major or minor limb ischaemia, and any bleeding at 1 month. Propensity score matching was performed to compare the primary outcome between UFH and fondaparinux.

Of 1,355 AMI survivors at 2 days after hospital admission and who underwent successful PCI, an IABP was inserted in 197 (14.5%): 72 (36.5%) were treated with UFH and 125 (63.5%) with fondaparinux (2.5 mg o.d.). At clinical follow-up, completed in 98.5% of cases, the incidence of the primary outcome was 22.5% in UFH and 5.7% in fondaparinux groups (p=0.0009). More than two-thirds of the events included in the primary outcome were related to early bleeding complications. In the matched cohort of 62 patients, the primary outcome occurred in 14 (45.2%) patients in the UFH and two (6.5%) in the fondaparinux group (p=0.01).

This study suggested that fondaparinux is safer, by reducing early bleeding complications at one month, than UFH in the management of IABP.