In a presentation at the UK Stroke Forum (4–6 December 2012, Harrogate, UK), Andre Ng, senior lecturer and consultant cardiologist, University of Leicester, Glenfield Hospital, Leicester, UK, spoke to delegates about the management of atrial fibrillation for the secondary prevention of stroke.
The speaker presented data that said atrial fibrillation increases the risk of stroke five-fold and that one third of atrial fibrillation patients will suffer a stroke in their lifetime. He added to this and said that atrial fibrillation is also responsible for 15–20% of ischaemic strokes and patients who have atrial fibrillation and have suffered a previous stroke or transient ischaemic attack are at a high risk of recurrent stroke with more disability.
The European Society of Cardiology guidelines for the management of atrial fibrillation in 2006 said that atrial fibrillation patients with a CHADS2 score of 2 and above are at high risk of transient ischaemic attack or stroke. The guidelines were reviewed in 2010 and, according to Ng, the CHA2DS2VASc score is now used to measure the risk of stroke or transient ischaemic attack for patients with atrial fibrillation with a score of 2 indicating the patient should be treated with oral anticoagulants.
Ng told delegates that, currently, the pharmacological options for atrial fibrillation patients for the prevention of stroke are vitamin K antagonists (VKA) such as warfarin, phenprocoumon, acenocoumarol and platelet inhibitors such as aspirin and clopidogrel. Ng said that the “classical” studies prove that treatment with warfarin prevents stroke. However, the speaker presented data from current trials on novel oral anticoagulants comparing warfarin and dabigatran (RE-LY trial), warfarin and rivaroxaban (ROCKET AF trial), and warfarin and apixaban (ARISTOTLE trial). The results of these trials, Ng told delegates, were that they all met their primary end points and therefore were proven to be as good as or better at reducing stroke than warfarin. Ng said that, for haemorrhagic stroke, the novel oral anticoagulants were superior for reducing stroke than warfarin and for ischaemic stroke were at least as good as warfarin.
Ng cited that “plugging” the left atrial appendage reduces clots forming that could lead to stroke this can be achieved percutaneously using devices such as Plaato (Appriva Medical), Watchman (Atritech/Boston Scientific) and Amplatzer plug (St Jude Medical). Ng also said devices such as the implantable cardiac monitor, Reveal XT (Medtronic), could capture data when patients are in atrial fibrillation and therefore monitor the risk of stroke.
Catheter ablation is an effective procedure in controlling symptoms in suitable atrial fibrillation patients and therefore may reduce the risk of stroke, according to Ng.
“In the management of atrial fibrillation for the secondary prevention of stroke diagnosis of atrial fibrillation needs to be actively sought, especially in patients who have had a stroke or a transient ischaemic attack,” said Ng. “A pragmatic approach would be, if an ischaemic cause cannot be found, to treat the patient with anticoagulants.”
“The novel oral anticoagulant drugs are at least as good, and in some instances better, than the current standard which is warfarin,” the speaker concluded.