The authors calculated the mean cost per patient In the Literature (continued) and the mean survival time between the two interventions. Future costs were discounted by 3%. For the base estimate, rhythm control was more expensive and less effective than rate control, i.e., dominated by the rate control. Rate control dominated rhythm control even for high and low estimates of the sensitivity analysis demonstrating stability of the results. Authors used 10,000 simulations to perform non-parametric bootstrapping analysis to find the 95% credible intervals around the base estimate. The bootstrap results showed that for 95% of the results rate control had higher survival time and was less costly than rhythm control. These simulation results clearly showed rate control is more cost-effective for patient population resembling that of AFFIRM trial.
The study has some limitations. These results are robust for patients similar to those in AFFIRM trial, i.e., older patients with cardiovascular defects that are at risk of cerebrovascular embolism. However these results may not be applicable to younger patients and those with “lone atrial fibrillation.” The study had a follow-up period of 3.5 years, and the cost-effectiveness analysis is confined to this period. It is difficult to determine mortality advantage of one treatment over another within the limited duration of the AFFIRM study. Most of the patients were on multiple pharmacologic agents for rhythm control and had a high incidence of cross-over from rhythm control to rate control reflecting modest benefits of the current agents. These results may not be applicable to patients whose atrial fibrillation is well controlled by a single agent or by non-pharmacological treatment. Patients on rhythm control agents had, as expected, more hospitalization days from the side effects and treatment protocols of the agents (especially pharmacologic) used to control the rhythm. With advances in both pharmacologic as well as nonpharmacologic methods for rhythm control generating safer and more efficacious technologies, the results of this analysis may become less valid in the future. The analysis was conducted from a third-party payer perspective, without accounting for the quality of life. Thus patients who have symptomatic atrial fibrillation and those with diastolic dysfunction may have improved quality of life from rhythm control over just rate control. The results may not be applicable to these patients. (SS)