EBQ:AFFIRM

Under Review Journal Club Article

Wyse DG, et al. "A Comparison of Rate Control and Rhythm Control in Patients with Atrial Fibrillation". NEJM. 2002. 347(23):1825-1833.
PubMed Full text PDF

Clinical Question

Which is better for treating atrial fibrillation, rate control allowing Afib at a lower heart rate, or rhythm control by maintaining sinus rhythm?

Conclusion

Rhythm control for Afib offers no survival advantage over rate control, and rate control is potentially advantageous given the lower risk of adverse drug reactions with rhythm control medications.

Study Design

• Multicenter, randomized controlled trial

Population

N= 4060 (7401 patients eligible and offered enrollment)

• Rate control group N=2027
• Rhythm control group N=2033

Patient Demographics

• Mean age: 69.7
• Women: 39.3%
• Ethnic minority: 11.3%
• Predominant cardiac diagnosis:
  • CAD: 26.1%
  • Cardiomyopathy: 4.1%
  • HTN: 50.8%
  • Valvular disease: 4.9%
  • Other: 1.0%
  • None: 12.4%
• Duration of qualifying Afib >2days: 69.2%
• First episode of Afib: 35.5%

Inclusion Criteria

• Age 65 or older or risk factors for stroke or death
• Diagnosis of atrial fibrillation that was:
  • recurrent
  • likely to cause illness or death
  • likely to require extended treatment

Exclusion Criteria

• Contraindication to anticoagulation
• Unable to take at least 2 drugs in each treatment group
• Unable to immediately start therapy after randomization

Interventions

• Rhythm control group attempted to maintain sinus rhythm. Antiarrhythmic drugs including: amiodarone, disopyramide, flecainide, moricizine, procainamide, propafenone, quinidine, sotalol, and combinations of the drugs were all possible. Treating physicians were allowed to choose the drug of their choice. Cardioversion was allowed as necessary.

• Rate control group attempted to maintain heart rate of 80 bpm or less while resting and 110 bpm or less with walking. Beta blockers, calcium-channel blockerrs, digoxin or combinations of the drugs were allowed. Again treating physicians could chose the drug of their choice.
• Non-pharmacologic interventions such as ablation and pacing could be pursued after the failure of at least 2 drugs from either treatment group
• INR of 2-3 was anticoagulation goal
  • Rhythm control group had the option of discontinuing anticoagulation if sinus rhythm was maintained for at least 4 consecutive weeks
  • Rate control group was maintained on anticoagulation

Outcomes

Primary Outcome

• Overal mortality at 5 years
  • Rhythym control 23.8%
  • Rate control 21.3%
  • Hazard ratio of 1.15 for rhythm control group- not statistically significant (p=0.08)

Secondary Outcomes

• Composite of:
  • Death
  • Disabling stroke
  • Disabling anoxic encephalopathy
  • Major bleeding
  • Cardiac arrest
• No difference between the two groups

See Also

• Ottawa Aggressive ED Cardioversion Protocol
• 48hr Cardioversion for Afib

Sources

Authors

Colin Hoff, Daniel Ostermayer, Ross Donaldson