The review included 120 studies (number of participants unclear).
Effect of radiofrequency catheter ablation on long-term and short-term outcomes: Six randomised controlled trials (RCTs, n=693 patients, five rated fair and one rated poor) plus two retrospective cohort studies (n=1,341 patients, both rated poor quality) were included in this analysis.
Moderate evidence (moderate confidence that evidence reflects the true effect): Radiofrequency catheter ablation as second line therapy was associated with better maintenance of sinus rhythm than medical therapy alone at 12 months (relative risk 3.46, 95% confidence interval (CI): 1.97 to 6.09, three RCTs).
Low level evidence (low confidence that evidence reflects the true effect): There was no significant difference between radiofrequency catheter ablation and medical therapy in the improvement of the following: left atrial diameter; left ventricular end diastolic diameter; ejection fraction at 12 months (one RCT); or in the risk of cerebrovascular events (six RCTs). Radiofrequency catheter ablation was associated with greater improvement in quality of life than medical treatment (measured by the 36-item short-form general health survey) (three RCTs and one observational study). The net difference between the two treatments was +1 to +25 in favour of radiofrequency catheter ablation. Radiofrequency catheter ablation was associated with a better chance of avoiding anticoagulation than treatment with antiarrhythmic drugs (60% versus 34%, p=0.02, one RCT). Trials examining readmission rates were inconsistent. One RCT reported lower readmission rates with radiofrequency catheter ablation than medical treatment (9% versus 54%, p<0.001). One RCT reported no significant difference between radiofrequency catheter ablation and medical treatment.
Insufficient evidence (evidence unavailable or does not permit estimation of an effect): One RCT found that patients with radiofrequency catheter ablation as first-line therapy had a greater rate of freedom from recurrence of atrial fibrillation at 12 months than with medical treatment (88% versus 37%, p<0.001). One observational study reported radiofrequency catheter ablation was associated with lower risk of congestive heart failure than medical therapy (5% versus 37%).
Effects of different radiofrequency catheter ablation techniques: Sixteen RCTs (n=2,023 patients), two non-randomised comparative trials (n=137 patients), two prospective cohort studies (n=595 patients) and 17 retrospective cohort studies (n=2,508 patients) were included in this analysis. Methodological quality of 11 studies was rated fair, the remainder poor.
Moderate evidence: There was a moderate level of evidence that wide area circumferential ablation was associated with lower rates of atrial fibrillation recurrence compared with ostial pulmonary vein isolation.
Insufficient evidence: There was insufficient evidence to form conclusions regarding effects of the addition of left-sided ablation lines to radiofrequency catheter ablation, or addition of right-sided lines on atrial fibrillation recurrence after radiofrequency catheter ablation.
Long and short term complications of radiofrequency catheter ablation: There was low level evidence that radiofrequency catheter ablation-related adverse events were relatively uncommon. Major adverse events were also reported to be relatively uncommon. Eighty-four studies reported at least one adverse event.
Patient level and intervention level characteristics associated with radiofrequency catheter ablation effect were also reported. Further results were reported.