Newer anticoagulants may carry different risks for bleeding complications in the elderly
Newer generation stroke prevention drugs have equal efficacy to older treatments, but carry different risk of bleeding complications in the elderly, finds a new study published in Circulation1 .
The meta-analysis, led by researchers from King’s College London, is the first to assess all available evidence for efficacy and bleeding outcomes of direct anticoagulants in elderly patients treated for stroke prevention. Anticoagulant therapy is essential for prevention of stroke in elderly people who are at higher risk due to atrial fibrillation or venous thromboembolism.
Dabigatran 150mg, one of the direct anticoagulants, was associated with a 78% higher risk of gastrointestinal bleeding than older anticoagulant drugs vitamin K antagonists, such as warfarin. However, the study also found 150mg dabigatran had a 57% lower risk of intracranial bleeding than vitamin K antagonists in the elderly.
The study analysed 11 trials that reported on elderly participants aged 75 years or older and found that all the direct anticoagulant drugs were equal to or better than the older vitamin K antagonists in managing stroke risks.
Dr Mariam Molokhia, senior author from the Department of Primary Care and Public Health at King’s College London, said: “Our study suggests that caution is required in prescribing where there may be additional risk factors for gastrointestinal bleeding in the elderly, particularly with the anticoagulant dabigatran.”
Manuj Sharma, lead author, from the Department of Primary Care and Public Health at King’s College London and from Guy's and St Thomas’ Hospital NHS Foundation Trust, said: “Though intracranial bleeds are more often life threatening when they occur, gastrointestinal bleeds are more common and can also have devastating effects. Hence it is important the anticoagulant chosen for a particular patient balances the benefit and risks of the particular drug against the history and risk profile for the patient being treated."
The other direct anticoagulants, apixaban and edoxaban, had a lower major bleeding risk compared to vitamin K antagonist, while rivaroxaban showed similar risk. The authors noted that insufficient published data for apixaban, edoxaban and rivaroxaban meant that all bleeding risks, particularly gastrointestinal risks could not be fully explored in the elderly.
“To determine bleeding risks further for these drugs, better availability of existing unpublished trial data is needed, in addition to more research,” said Dr Molokhia.
1‘Efficacy and harms of direct oral anticoagulants in the elderly for stroke prevention in atrial fibrillation and secondary prevention of venous thromboembolism: systematic review and meta-analysis’ by Sharma et al is published in Circulation. doi: 10.1161/CIRCULATIONAHA.114.013267