With regard to the AAN guideline, he added: "There is no discussion of truly long-term monitoring in the guideline, which is unfortunate." That said, "anything that gets neurologists thinking about long-term cardiac monitoring is likely to be beneficial."
Anticoagulation for stroke prevention
The AAN guideline also provides general recommendations on the use of novel oral anticoagulant agents (NOACs) as alternatives to warfarin. Specifically, it notes that in comparison with warfarin, these NOACs are probably at least as effective (rivaroxaban) or more effective (dabigatran and apixaban). Additionally, while apixaban is also likely to be more effective than aspirin, it is associated with a similar risk for bleeding. NOACs have the following advantages over warfarin: an overall lower risk of intracranial hemorrhage and no need for routine anticoagulant monitoring.
From a practical perspective, the AAN guideline suggests that clinicians have the following options available: warfarin to reach an INR of 2.0-3.0, dabigatran 150 mg twice daily, rivaroxaban 15-20 mg/dL, apixaban 2.5-5 mg twice a day, and triflusal 600 mg plus acenocoumarol to reach an INR target of 1.25-2.0. If a patient is already taking warfarin and is well controlled, then they should remain on that therapy and not switch to a newer oral anticoagulant.
The guideline also notes that clopidogrel plus aspirin is probably less effective than warfarin, but the combination is probably better than aspirin alone. However, the risk of hemorrhage is higher.
Where used, triflusal plus acenocoumarol is "likely more effective" than acenocoumarol alone. Triflusal is an antiplatelet drug related to aspirin, used in Europe, Latin America, and Southeast Asia. Acenocoumarol is mostly used in European countries.
Dr. Culebras explained that the guideline was not intended to dictate which treatment to use. "The guideline leaves room on purpose for clinicians to use their judgment," he said. "The overall objective of the guideline is to reduce therapeutic uncertainty and not to issue commandments for treatment."
Although Dr. Bernstein was critical of the guidelines for not advocating the use of anticoagulants strongly enough, he said that the recommendations on anticoagulant choice are "reasonable in that they impute potential clinical profiles of patients who might particularly benefit from one NOAC over another, without making a claim that these recommendations are based on solid data. This reflects how doctors make decisions when we don’t have direct comparative studies, and I think that is helpful."
The guideline was developed with financial support from the American Academy of Neurology. None of the authors received reimbursement, honoraria, or stipends for their participation in the development of the guideline.
Dr. Culebras has received one-time funding for travel from J. Uriach & Co, and he serves on the editorial boards of MedLink, UpToDate.com, and the International Journal of Stroke. He has received royalties from Informa Healthcare and Cambridge University Press, and has held stock in Clinical Stroke Research. Other authors reported current or past ties to companies marketing oral anticoagulants and stroke treatments.
Dr. Bernstein was on the steering committee for the CRYSTAL-AF study and is a paid speaker, researcher, and consultant for Medtronic, Bristol-Myers Squibb, Pfizer, Boehringer Ingelheim, and Lifewatch.
*Correction, 4/8/2014: The article previously misstated what the implantable device was detecting in the CRYSTAL-AF study.