What are the main conclusions from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trials comparing rate control and rhythm control in atrial fibrillation (AFib) management?

From the Guidelines

Rate control is the preferred strategy for managing atrial fibrillation in most patients, as it has been shown to be non-inferior to rhythm control in terms of mortality and stroke prevention, with fewer hospitalizations and adverse effects, as demonstrated in the AFFIRM trial 1. The AFFIRM trials compared rate control and rhythm control in atrial fibrillation management, with a primary endpoint of overall mortality, and found no statistically significant difference between the two groups. However, the rhythm-control strategy was associated with a higher risk for death among older patients, those without congestive heart failure, and those with coronary disease.

Key Findings

• The prevalence of sinus rhythm in the rhythm-control group was 82%, 73%, and 63% at 1,3, and 5 years, respectively, while in the rate-control group it was 34.6% at 5 years 1.
• Rates of stroke did not differ between groups, with 70% of all strokes occurring in patients who had stopped receiving anticoagulation or who had subtherapeutic international normalized ratios (<2.0) 1.
• More hospitalizations were reported in the rhythm-control group (P < 0.001) 1.

Treatment Recommendations

• Rate control involves using medications like beta-blockers (metoprolol 25-200 mg twice daily, carvedilol 3.125-25 mg twice daily), calcium channel blockers (diltiazem 120-360 mg daily, verapamil 120-360 mg daily), or digoxin (0.125-0.25 mg daily) to maintain a resting heart rate below 110 beats per minute.
• Rhythm control, which attempts to restore and maintain normal sinus rhythm using antiarrhythmic drugs like amiodarone, sotalol, or flecainide, plus cardioversion as needed, may be considered in younger patients with highly symptomatic paroxysmal atrial fibrillation.
• Anticoagulation remains essential regardless of the strategy chosen, with warfarin (target INR 2-3) or direct oral anticoagulants like apixaban, rivaroxaban, or dabigatran recommended based on stroke risk assessment using the CHA₂DS₂-VASc score.

Patient-Specific Considerations

• The choice between rate and rhythm control should be individualized based on patient age, symptoms, comorbidities, and preferences.
• Older patients, those with minimal symptoms, and those with coronary disease may benefit from rate control, while younger patients with highly symptomatic paroxysmal atrial fibrillation may benefit from rhythm control.

From the Research

Main Conclusions from the AFFIRM Trials

The main conclusions from the AFFIRM trials comparing rate control and rhythm control in atrial fibrillation (AFib) management are:

• Rate control is an acceptable treatment strategy for AFib, with no significant difference in morbidity, mortality, and quality of life compared to rhythm control 2, 3
• The AFFIRM study showed that atrial fibrillation can be treated effectively with rate control and anticoagulation, but drug efficacy to control rate remains uncertain 4
• Beta-blockers were found to be the most effective drugs for achieving rate control in AFib patients 4
• The intensity of rate-control does not significantly influence outcome in AFib, with both strict and lenient rate control approaches showing similar results 5
• Anticoagulation must be continued if stroke risk factors are present, even if patients maintain sinus rhythm 2, 3

Key Findings

• The AFFIRM study demonstrated that rate control and rhythm control strategies result in similar survival and quality of life for patients with AFib 6
• The use of rhythm controlling medications and cardioversion procedures decreased after the publication of the AFFIRM trial, while the use of rate controlling medications increased 6
• The RACE study found that rate control was not inferior to rhythm control in terms of morbidity, mortality, and quality of life 2
• The AFFIRM and RACE studies suggest that rate control is an acceptable alternative to rhythm control in patients with recurrent AFib 2, 3

Clinical Implications

• Rate control is now the recommended strategy for the management of most elderly, high-risk AFib patients due to its superior safety and lower cost 6
• The choice between rate control and rhythm control should be individualized based on patient characteristics and symptoms 3
• Anticoagulation therapy should be continued in patients with stroke risk factors, regardless of the treatment strategy used 2, 3