GPAC guideline: Stroke and atrial fibrillation

Four new guidelines make up the BCGuidelines.ca Stroke and Atrial Fibrillation series. The series includes Atrial Fibrillation—Diagnosis and Management; Use of Non-Vitamin K Antagonist Oral Anticoagulants (NOAC) in Non-Valvular Atrial Fibrillation; Stroke and Transient Ischemic Attack—Acute and Long-Term Management; and Warfarin Therapy Management. All guidelines are available to physicians across BC via www.BCGuidelines.ca.

Atrial Fibrillation—Diagnosis and Management 
Key recommendations:
•   Determine the patient’s cardiac stability and provide emergency stabilization if needed.
•   Consider all patients with atrial fibrillation for antithrombotic therapy (short- and long-term).
•   Establish the risk of stroke in patients with atrial fibrillation using age (= 65) and CHADS.
•   Oral anticoagulants are recommended in patients with CHADS2 = 0 and age = 65 years.
•   The goals of rate and/or rhythm control strategies are to improve patient symptoms, exercise tolerance, quality of life, prevent hospitalizations, and improve left ventricular function.
•   Manage comorbidities that may raise atrial fibrillation risk, such as hypertension, diabetes, and heart failure.

Use of Non-Vitamin K Antagonist Oral Anticoagulants in Non-Valvular Atrial Fibrillation
Key recommendations:
•   Non-vitamin K antagonist oral anticoagulants (NOACs) are a class of anticoagulants each with distinct pharmacologic characteristics and should not be considered interchangeable.
•   NOACs can be considered for prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation in whom anticoagulation is indicated. 
•   Renal function should be checked prior to starting a NOAC and then periodically depending on clinical status.
•   Check for potential drug interactions that may increase or decrease the drug levels of the NOAC and consider alternative therapy if any significant interaction is present.
•   Choice of agent for an individual patient is based on clinical factors, including the risk for stroke, bleeding history, renal and liver function, warfarin experience, and personal preference.

Stroke and Transient Ischemic Attack—Acute and Long-Term Management
Key recommendations:
•   Stroke and emergent transient ischemic attacks are medical emergencies and patients should be immediately sent to an emergency department. 
•   Timely investigation and management of transient ischemic attacks significantly reduces the chance of stroke.
•   Thrombolytic eligible patients should receive tissue plasminogen activator (tPA) as quickly as possible (within 4.5 hours of clearly defined symptom onset).
•   Early mobilization and appropriate positioning within 24 hours are associated with improved outcomes.
•   Management on a stroke rehabilitation unit improves functional outcomes.

Warfarin Therapy Management
Key recommendations:
•   Warfarin should be dosed to achieve the target therapeutic INR for the specific indication. Under- or over-anticoagulation is associated with high risks of thrombosis and bleeding.
•   Consider using a standard dosing nomogram or computerized decision-support software to maximize the time in therapeutic range.
•   Patients are advised to maintain a stable and consistent intake of vitamin K in their diet and not avoid vitamin K–containing foods.
•   Patient and caregiver education is necessary to promote compliance and stability of warfarin anticoagulation.