Objective To determine whether or not radiofrequency ablation (RFA) for persistent atrial fibrillation in patients with advanced heart failure leads to improvements in cardiac function.

Setting Patients were recruited from heart failure outpatient clinics in Scotland.

Design and intervention Patients with advanced heart failure and severe left ventricular dysfunction were randomised to RFA (rhythm control) or continued medical treatment (rate control). Patients were followed up for a minimum of 6 months.

Main outcome measure Change in left ventricular ejection fraction (LVEF) measured by cardiovascular MRI.

Results 22 patients were randomised to RFA and 19 to medical treatment. In the RFA group, 50% of patients were in sinus rhythm at the end of the study (compared with none in the medical treatment group). The increase in cardiovascular magnetic resonance (CMR) LVEF in the RFA group was 4.5±11.1% compared with 2.8±6.7% in the medical treatment group (p=0.6). The RFA group had a greater increase in radionuclide LVEF (a prespecified secondary end point) than patients in the medical treatment group (+8.2±12.0% vs +1.4±5.9%; p=0.032). RFA did not improve N-terminal pro-B-type natriuretic peptide, 6 min walk distance or quality of life. The rate of serious complications related to RFA was 15%.

Conclusions RFA resulted in long-term restoration of sinus rhythm in only 50% of patients. RFA did not improve CMR LVEF compared with a strategy of rate control. RFA did improve radionuclide LVEF but did not improve other secondary outcomes and was associated with a significant rate of serious complications.

Clinical trials registration number NCT00292162.