New drugs and more complex patients make anticoagulation for atrial fibrillation a new ballgame. Here, a topline from guidelines for primary care.
With the approval and expanding use of new anticoagulant agents, anticoagulation for atrial fibrillation (AF) has become a more nuanced therapeutic strategy. There are more choices, making patient selection more complex and more and different types of patients who require care that spans specialties. Following are 7 topline facts that primary care physicians need to know about the most recent American College of Cardiology consensus recommendations on anticoagulation therapy for AF.
Adapted from sources below
1. Oral anticoagulation should be considered in patients with CHA2DS2-VASc score of 1 and is recommended in those with a score of ≥2.
2. Options for anticoagulation include:
a. Vitamin K antagonist (warfarin)
b. Direct thrombin inhibitor (dabigatran/Pradaxa)
c. Factor Xa inhibitor (rivaroxaban/Xarelto; apixaban/Eliquis; edoxaban/Savaysa)
Choice of agent depends on patient specific factors, including cost, renal function, compliance, age, comorbidities. There are reversal agents available for warfarin and dabigatran, but currently there is no “antidote” for the factor Xa inhibitors.
Drug-drug interactions with warfarin are numerous; known interactions with the novel oral anticoagulants (NOACs), include CYP3A4 inhibitors/inducers and P-glycoprotein inducers such as rifampin, quinidine, dronedarone, verapamil, and antiretroviral medications. Efficacy of edoxaban is reduced in patients with creatinine clearance of >95 mL/min.
3. For patients prescribed “triple therapy” (aspirin, thienopyridine, anticoagulant) for indications such as recent acute coronary syndrome, use of clopidogrel is preferred over newer antiplatelet agents (ticagrelor/Brilinta; prasugrel/Effient). Two ongoing trials (RE-DUAL PCIa and PIONEER-AF PCIb) are investigating anticoagulation with warfarin vs with a NOAC in patients who have undergone percutaneous coronary intervention. There is currently not enough data to know whether warfarin is the preferred agent over NOACs in this setting.
4. Use of NOACs is not recommended for patients with valvular atrial fibrillation (AF) or those with prosthetic valves. Currently all four NOACs (dabigatran/Pradaxa, rivaroxaban/Xarelto, apixaban/Eliquis, edoxaban/Savaysa) have been studied and approved for other indications such as deep venous thrombosis treatment and prophylaxis.
5. NOACs (in addition to warfarin) can be used safely for patients with AF undergoing cardioversion or radio frequency ablation. Specific recommendations for continued use and temporary interruption pertain.
6. Rhythm control is making a comeback! Patients who are younger and highly symptomatic can be considered for rhythm control rather than rate control.
7. Referral for radio frequency ablation should be considered earlier in the course of AF before the arrhythmia progresses from paroxysmal to permanent, particularly in those patients who are highly symptomatic from their AF.
aRandomized evaluation of dual therapy with dabigatran vs triple therapy strategy with warfarin in patients with non-valvular AF that have undergone PCI with stents [NCT02164864]
bOpen-label, randomized, controlled, multicenter study exploring two treatment strategies of rivaroxaban and a dose-adjusted oral vitamin K antagonist strategy in subjects with atrial fibrillation who undergo percutaneous coronary intervention. [NCT01830543])
Barnes, Geoffrey. http://www.acc.org/latest-in-cardiology/ten-points-to-remember/2015/03/30/15/42/practical-management-of-anticoagulation-in-patients-with-atrial-fibrillation.
Kovacs RJ, Flaker GC, Saxonhouse SJ, et al. Practical management of anticoagulation in patients with atrial fibrillation. J Am Coll Cardiol. 2015;65:1340-1360. http://content.onlinejacc.org/article.aspx?doi=10.1016/j.jacc.2015.01.049&_ga=1.106121419.950741061.1458838710