"Lenient vs Strict Rate Control in Patients with Atrial Fibrillation". The New England Journal of Medicine. 2010. 362:1363-1373. PubMed•Full text•PDF

Contents

1 Clinical Question
2 Bottom Line
3 Major Points
4 Guidelines
5 Design
6 Population
6.1 Inclusion Criteria
6.2 Exclusion Criteria
6.3 Baseline Characteristics
7 Interventions
8 Outcomes
8.1 Primary Outcome
8.2 Secondary Outcomes
9 Criticisms
10 Funding
11 Further Reading

Clinical Question

In patients with permanent atrial fibrillation, is lenient rate control inferior to strict rate control for preventing cardiovascular morbidity and mortality?

Bottom Line

In patients with permanent atrial fibrillation, lenient rate control was not inferior to strict rate control for the prevention of cardiovascular morbidity and mortality and was easier to achieve.

Major Points

Guidelines

Current guidelines recommend a heart rate of <110 beats per minute in asymptomatic patients with permanent atrial fibrillation without the need for strict rate control unless the patient has symptoms.

Design

Multicenter, randomized, open-label, noninferiority trial.

Population

N=614 patients with permanent atrial fibrillation.

Inclusion Criteria
Permanent atrial fibrillation up to 12 months, age ≤80 years, mean resting heart rate >80 beats per minute, and use of oral anticoagulation therapy.

Exclusion Criteria
Disclosed previously by the study.

Baseline Characteristics
Well matched, with a higher prevalence of coronary artery disease and statin use in the lenient-control group.

Interventions

Randomly assigned to either lenient rate-control strategy (resting heart rate <110 beats per minute) or strict rate-control strategy (resting heart rate <80 beats per minute and heart rate during moderate exercise <110 beats per minute).

Outcomes

Primary Outcome
Composite of death from cardiovascular causes, hospitalization for heart failure, and stroke, systemic embolism, bleeding, and life-threatening arrhythmic events: 12.9% in lenient-control group vs. 14.9% in strict-control group at 3 years (P<0.001 for noninferiority).

Secondary Outcomes
Similar frequencies of the components of the primary outcome between groups.

Criticisms

Study population may be considered low-risk, physically active patients, potentially limiting generalizability.

Funding

Supported by the Netherlands Heart Foundation, AstraZeneca, Biotronik, Boehringer Ingelheim, Boston Scientific, Medtronic, Roche, and Sanofi Aventis France.

Further Reading

The original publication and supplementary material can be accessed through The New England Journal of Medicine website.