The use of low-molecular-weight heparin bridging therapy for secondary prevention after an acute stroke is being questioned after new evidence showed increased risks of ischaemic recurrence and intracerebral bleeding.

It may be preferable to use direct acting oral anticoagulants (DOACs) that have a rapid onset and are reversible rather than slow-onset vitamin K antagonists such as warfarin that require prior bridging therapy, according to an Australian neurologist.

Writing in Stroke, Professor Bruce Campbell of the Department of Neurology, Royal Melbourne Hospital notes that a new analysis of the RAF Study found that LMWH bridging therapy in nonvalvular AF patients hospitalised for a recent ischaemic stroke was associated with a higher risk of early ischemic and haemorrhagic events compared with non-bridged patients.

In the observational study involving 1810 patients who started early anticoagulation after ischaemic stroke , the risk of major bleeding events was higher with bridging (5.1% vs 2.3%; adjusted odds ratio, 2.4). There was also an increase in ischaemic events in the bridging group (7.8% vs 3.1%; OR 2.2).

The ischaemic stroke risk in the nonbridging patients was significantly lower when a DOAC was initiated (2.5%) vs warfarin (5.5%), likely due to the immediate and reliable anticoagulation achieved by DOACs compared with unpredictable and delayed anticoagulation with warfarin, according to Professor Campbell.

“The data … add to the accumulated evidence supporting commencement of a DOAC in preference to vitamin K antagonists poststroke for nonvalvular AF patients with adequate renal function,” he said.

“There is no benefit in using LMWH before commencing the DOAC and clear risk of doing so,” he added.

And although the best time to start a DOAC after ischaemic stroke was still not certain, observational data suggested it would be safe within a few days for most patients, said Professor Campbell.

“For patients unsuitable for DOAC, there is also no indication that bridging is beneficial before achieving a therapeutic level of a vitamin K antagonist,” he wrote.

In the study, 20% of patients underwent bridging therapy with full-dose LMWH. Patients were less likely to receive bridging therapy if they were older age and had leukoaraiosis.