Rate control effective in patients with both AF and CHF
Rate control is as effective as rhythm control in preventing mortality in patients with AF and heart failure.
The study enrolled 1,376 patients with a left ventricular ejection fraction of 35%, symptoms of CHF and a history of ECG-confirmed AF.
Participants were randomised to either maintenance of sinus rhythm with electrical cardioversion and antiarrhythmic drugs such as amiodarone (rhythm control: 682 patients) or control of ventricular rate using beta blockers and digoxin, with atrioventricular nodal ablation and pacemaker insertion if the study rate control targets were not achieved (rate control: 694 patients). The patients were followed up for a mean of 37 months. The primary outcome measure was cardiovascular mortality.
The results showed no significant difference in cardiovascular mortality between the two groups, with 182 patient deaths in the rhythm control group and 175 in the rate control group (27% and 25% of participants respectively). After adjustment for baseline variables reflecting LV function, heart failure class, comorbidities, use of implantable devices, duration of AF, renal function and medical therapy, the odds ratio was 1.05 (95% CI 0.85-1.29, P=0.67).
Furthermore, secondary outcomes were also similar in the two groups, including all-cause mortality (32% and 33% in the rhythm and rate groups respectively), stroke (3% versus 4%), worsening heart failure (28% versus 31%) and a composite of mortality from cardiovascular causes, stroke and worsening heart failure (43% versus 46%).
One of the key issues in the successful management of AF is whether to adopt a rate or rhythm control strategy. Current evidence suggests outcomes are better with a rate control strategy in most patients. However, patients with heart failure have been felt to be a notable exception to this rule.
This trial appears to support the gathering weight of evidence for a rate control strategy in patients with AF. It would seem that rhythm control is falling from favour and will be reserved for young patients and those with refractory symptoms or an acute presentation.
Roy D, Talajic M, Nattel S et al. Rhythm Control versus Rate Control for Atrial Fibrillation and Heart Failure. N Engl J Med 2008;358:2667-77A 12-lead electrocardiogram (ECG) of atrial fibrillation Atrial fibrillation Reviewer
Dr Peter Savill
GPwSI Cardiology, Southampton