Rate or Rhythm Control in Persistent Atrial Fibrillation?

Abstract & Commentary

Synopsis: Quality of life is impaired in patients with atrial fibrillation compared to healthy controls, but treatment strategy for atrial fibrillation results in the same net effect on quality of life.

Source: Hagens VE, et al, for the RACE Study Group. J Am Coll Cardiol. 2004;43:241-247.

The Rate Control vs Electrical Cardioversion for Persistent Atrial Fibrillation (RACE) study compared a rate control strategy vs a rhythm control strategy in patients with persistent atrial fibrillation. Hagens and colleagues had previously reported that there was no significant difference in mortality and that there was an excess of adverse cardiac events associated with the rhythm control strategy. In this paper, they deal with quality-of-life issues.

Patients were eligible for RACE if they had recurrent, persistent atrial fibrillation. Follow-up quality-of-life questionnaires were administered at baseline after 1 year and at the end of follow-up. Patients who died during follow-up (18 patients in each group) were not included. Quality-of-life data were not complete in another 134 patients, and 1 or more of the quality-of-life questionnaires was not available. The patients excluded did not differ significantly from included patients in terms of their baseline characteristics.

Quality of life was assessed using the Medical Outcomes Study Short-Form 36 (SF-36) questionnaire. This instrument has been translated and validated in the Netherlands, the country in which RACE was conducted.

At baseline, all patients were compared with a healthy, age-matched control group consisting of 172 Dutch individuals who originally served to validate the Dutch version of the SF-36. At baseline, at 1 year, and at the end of the study, the scores on all the subscales of the SF-36 were compared between the rate control and rhythm control groups.

At baseline, there were no significant differences in quality of life between the rate and rhythm control groups; however, quality of life was lower for patients in RACE compared with a healthy, age-matched control group. Differences in physical and emotional role limitations were highest. Differences in vitality, social functioning, and general health were also significant. Bodily pain was higher in the atrial fibrillation patients. Low quality-of-life scores for physical health at baseline were more frequent among females, patients younger than 69, patients with an atrial fibrillation duration above the median of 32 days, and patients with reduced exercise tolerances. Low quality-of-life scores for mental health were more frequent among patients older than 69. The correlation between complaints associated with atrial fibrillation (fatigue or palpitations) had a reduced score for both physical and mental health parameters. There was an improvement in many of the quality-of-life parameters over time during the study in both groups. 

In the rate control group, 4 subscales of the SF-36 had improved. At study end, 3 subscales had significantly improved. These were role limitations due to physical problems, social functioning, and mental health. In the rhythm control group, quality of life improved at 1 year on 3 subscales, but at the end of the study, no significant changes were present compared with baseline scores. From the scores on the SF-36, subscales at the 12-month follow-up and study end were compared between the rate and rhythm control groups; no significant differences were found in any of the 8 subscales. Complaints of palpitations, fatigue, and dyspnea, which were thought to be related to atrial fibrillation, were common in both groups. An analysis of baseline variables that might be associated with quality-of-life changes was performed. Stepwise regression analysis showed that age younger than 69, symptoms of atrial fibrillation (fatigue, palpitations, or dyspnea), a short duration of atrial fibrillation, and sinus rhythm at the end of follow-up were determinants of relevant quality-of-life improvement during follow-up. Interestingly, although sinus rhythm at the end of follow-up was a predictor of improved quality of life, the type of randomized strategy (rate or rhythm control), was not associated with improved quality of life.

Hagens et al conclude that quality of life is impaired in patients with atrial fibrillation compared to healthy controls, but treatment strategy for atrial fibrillation results in the same net effect on quality of life.

Comment by John DiMarco, MD, PhD

These data about quality of life from the RACE trial are quite important. The data here show that there is no clear-cut advantage to a rhythm control strategy even in terms of symptoms. However, the observation that there was a trend toward an improvement in symptoms if sinus rhythm could be maintained has 2 implications. First, patients who are highly symptomatic in atrial fibrillation are more likely to get benefit from an initial rhythm control strategy. Unfortunately, these patients are also those who are often the most likely to go back into atrial fibrillation so the net long-term effect in a large group is small, but the individual effect in the proportion who respond may be great. Therefore, the data from this trial and data that will be published from the AFFIRM study suggest that asymptomatic patients will probably not benefit much from attempts to maintain normal sinus rhythm. However, if there are significant symptoms and if the patient falls into that minor fraction in which sinus rhythm can be restored and maintained in a relatively simple fashion, then a rhythm control strategy may be indicated. In all cases, an appropriate anticoagulation program should also be followed.

Dr.DiMarco, Professor of Medicine, Division of Cardiology, University of Virginia, Charlottesville, is on the Editorial Board of Clinical Cardiology Alert.