Priority Topic: Atrial Fibrillation

Key Feature 3a: In an individual presenting with chronic or paroxysmal atrial fibrillation: Explore the need for anticoagulation based on the risk of stroke with the patient.
Skill: Patient Centered, Clinical Reasoning
Phase: Diagnosis, Treatment

Key Feature 3b: In an individual presenting with chronic or paroxysmal atrial fibrillation: Periodically reassess the need for anticoagulation.
Skill: Clinical Reasoning
Phase: Hypothesis generation, Follow-up

Key Feature 4: In patients with atrial fibrillation, when the decision has been made to use anticoagulation, institute the appropriate therapy and patient education, with a comprehensive follow-up plan.
Skill: Clinical Reasoning
Phase: Treatment, Follow-up

Key Feature 5: In a stable patient with atrial fibrillation, identify the need for rate control.
Skill: Clinical Reasoning
Phase: Hypothesis generation, Treatment

Key Feature 6: In a stable patient with atrial fibrillation, arrange for rhythm correction when appropriate.
Skill: Clinical Reasoning, Selectivity
Phase: Hypothesis generation, Treatment

In a patient with atrial fibrillation, whether or not they should be anticoagulated is based on the risk for stroke versus having a serious bleed. The CHADS2-VASc risk stratification score is the standard assessment tool to assess for the risk of stroke, while the HAS-BLED risk stratifications score is the equivalent to asses for the risk of a major bleed. In realtime, I use a medical calculator app (Canadian Cardiovascular Society) to determine the risk scores for the patient in front of me to help me make a decision. It's important to have a patient-centered conversation. Although the chances of having a major bleed may be higher for the patient than the risk of stroke based on their risk stratification scores, the majority of such patients may prefer to be anticoagulated given the proportional risk for decrease in quality of life should one versus the other occur. It is important to periodically reassess the need for anticoagulation as a patient's risk of stroke, risk of sustaining a major bleed, and goals of care may change over time. 

The Canadian Cardiovascular Society Atrial Fibrillation Guideline recommends the following for prevention of stroke and systemic embolism:

• Recommendation 1: Stratification of patients using a predictive index for stroke risk
• Recommendation 2: Oral anticoagulant therapy (OAC) for patients ≥ 65 years or CHADS2-VASc ≥ 1
• Recommendation 3: Acetylsalicylic acid (ASA) for patients with no risks besides arterial vascular disease
• Recommendation 4: No antithrombotic therapy for patients with no major risks​
• Recommendation 5: Most patients should receive non-vitamin K oral anticoagulant therapy (NOAC)
• Recommendation 6: Warfarin when mechanical valve, mitral stenosis, or renal dysfunction (15-30 mL/min)
• Recommendation 7: Patients who refuse OAC should receive ASA pus clopidogrel
• Recommendation 8: OAC therapy for highly selected patients with subclinical atrial fibrillation (AF)
• Recommendation 9: OAC for 3 weeks before and at least 4 weeks post cardioversion
• Recommendation 10: Annual renal function assessment
• Recommendation 11: Antithrombotic therapy should relate to creatinine clearance (CrCl)
• Recommendation 12: Left atrial appendage closure devices to be used only in research and exceptional cases
• Recommendation 13: Acute management of stroke patients as per American Heart Association (AHA)/American Stroke Association (ASA) guidelines (i.e., ACLS)
• Recommendation 14: Hemorrhage on OAC to be managed per American College of Chest Physicians (AACP) guidelines 
• Recommendation 15: Idarucizimab for emergency reversal of dabigatran's anticoagulant effect

In follow-up care of a patient who has been diagnosed with atrial fibrillation, be it paroxysmal, persistent, or permanent, the following issues should be reviewed:

1. Symptoms and functional status
2. Review of management for stroke risk
3. Review of management for either rhythm or rate control (see below)
4. Routine investigations may include repeat ECG and bloodwork to reassess kidney and liver functioning

The Canadian Cardiovascular Society Atrial Fibrillation Guideline recommends the following for rate control of Atrial Fibrillation:

1. ​Recommendation 1: Goals of rate control therapy should be to improve symptoms and clinical outcomes which are attributable to excessive ventricular rates
2. Recommendation 2: Ventricular rate should be assessed in all patients at rest
3. Recommendation 3: Heart rate (HR) during exercise should be assessed, along with associated exertional symptoms
4. Recommendation 4: Aim for a resting HR < 100 bpm
5. Recommendation 5: Beta-blockers or nondihydropyridine calcium channel blockers (CCB) as initial therapy
6. Recommendation 6: Digoxin rate control: selected sedentary and left ventricular (LV) systolic dysfunction patients
7. Recommendation 7: Digoxin added when other therapies fail
8. Recommendation 8: Amiodarone for rate control therapy in exceptional cases
9. Recommendation 9: Dronedarone, not for patients with permanent AF
10. Recommendation 10: Dronedarone, not for patients with history of heart failure (HF)
11. Recommendation 11: Dronedarone, to be used with caution with patients taking digoxin
12. Recommendation 12: Beta-blockers as initial therapy in patients with MI or LV systolic dysfunction
13. Recommendation 13: Atrial ventricular node (AVN) ablation pacemaker in symptomatic drug-refractory patients

The Canadian Cardiovascular Society Atrial Fibrillation Guideline recommends the following for rate control of Atrial Fibrillation:

1. Recommendation 1: Treat precipitating or reversible conditions
2. Recommendation 2: Rhythm control strategy for patents symptomatic on rate control therapy
   
3. Recommendation 3: Goal of rhythm control therapy should be improvement in patient symptoms and clinical outcomes, and not necessarily the elimination of all AF
   
4. Recommendation 4: Maintenance antiarrhythmic drugs first-line in patients with recurrent AF
   
5. Recommendation 5: Avoid antiarrhythmic in patients with advanced sinus or AV node disease
   
6. Recommendation 6: AV blocking agent to be used along with a class I antiarrhythmic drug
   
7. Recommendation 7: 'Pill in the pocket' therapy in patients with infrequent AF
8. Recommendation 8: Electrical or pharmacological cardioversion for sinus rhythm restoration
   
9. Recommendation 9: Pretreatment with antiarrhythmic drugs before electrical cardioversion
   
10. Recommendation 10: For symptomatic bradycardia, dual-chamber pacing
    
11. Recommendation 11: Pacemaker to be programmed to minimize ventricular pacing