RACE II Rate Control Assessment Tool – Atrial Fibrillation Heart Rate Target

About RACE II Rate Control

The Rate Control Efficacy in Permanent Atrial Fibrillation (RACE II) trial compared a lenient rate-control strategy with a strict rate-control strategy in 614 patients with permanent atrial fibrillation.

Key trial finding

At 3 years, the estimated cumulative incidence of the primary composite outcome was 12.9% with lenient control and 14.9% with strict control. Lenient control met the trial's prespecified non-inferiority criterion and required fewer visits to achieve target control.

How to use this assessment

• Use the resting heart rate to assess the lenient target.
• Assess the strict strategy using both resting and moderate-exercise heart rates.
• Interpret target attainment together with symptoms, ventricular function, comorbidities, and the overall treatment strategy.

Clinical Considerations

Lenient rate control is an acceptable initial approach for many patients. A stricter target may be considered when AF-related symptoms continue despite rate-control treatment or when tachycardia-induced/AF-induced cardiomyopathy is suspected.

The 2023 ACC/AHA/ACCP/HRS guideline generally recommends symptom-guided resting targets of <100–110 bpm in patients with AF without heart failure. A stricter target (<80 bpm at rest and <110 bpm during moderate exercise) may be reasonable in suspected AF-induced cardiomyopathy or refractory HF symptoms.

Important: RACE II studied permanent AF. Its findings should not automatically be extrapolated to every AF phenotype or to patients with highly symptomatic AF, significant heart failure, or suspected rate-related ventricular dysfunction.