Dabigatran appears to be feasible and safe in the management of non-AF associated acute ischaemic stroke or TIA, an Australian study shows.

The phase 2 DATAS II study randomised 305 stroke /TIA patients to either dabigatran (mostly 150mg daily) or aspirin (81mg) for 30 days.

The study, published in Stroke, reported that no patients in either arm experienced the primary end point of symptomatic hemorrhagic transformation (HT).

While asymptomatic HT was evident on MRI at 30 days in more dabigatran patients than aspirin patients (7.8% v 3.5%), the  difference was not statistically significant.

Only DWI lesion volume predicted incident asymptomatic HT, the study found.

The rate of recurrent ischaemic events was similar in both arms of the study with new or progressive lesions seen in 6.3% of patients on dabigatran and 9.8% in patients on aspirin.

Median lesion volume was found to be larger in the dabigatran-treated patients.

The study authors, led by Professor Ken Butcher from the Prince of Wales Hospital and the University of NSW, said the absence of symptomatic HT was encouraging given the excessive HT rates associated with older anticoagulants.

“This finding is reassuring with respect to the safety of dabigatran in the immediate poststroke period and should be applicable across a broad range of underlying etiologies,” they wrote.

“Although not clinically evident or statistically significant, dabigatran was associated with numerically more microscopic hemorrhagic transformation events than aspirin, which is consistent with the relative antithrombotic potency of an anticoagulant versus an antiplatelet agent.”

Professor Butcher told the limbic the study provided the first randomised safety data with respect to early initiation of anticoagulation after cardioembolic stroke.

“We’re always worrying about starting too early because of HT but on the other hand if you wait too long, you get more cardioembolic stroke. It is okay to start early in this population,” he said.

He said the study was underpowered to show efficacy.

“This is not a clinical trial that is going to change clinical practice. It was a trial that showed it was safe and reasonable to use these drugs in the acute setting in this population.”

“The proof of concept is actually being explored in new trials of next generation DOACs, the factor XI antagonists, in addition to antiplatelet agents,” he said.

The study noted that only 1.3% of patients were identified to have AF.

“Thus, although early dabigatran initiation appeared to be safe in our patients, the risk/benefit ratio of this practice has not been established following AF-related stroke,” the study authors said.

“Furthermore, our patients all had low NIHSS scores (≤3) and relatively small MRI-defined infarcts. Determining the safety and utility of early NOAC treatment in patients with larger, AF-related stroke is the aim of ongoing trials …”