Limitations
There are several important limitations to note. This is a retrospective analysis and is therefore inherently subject to selection bias which may have impacted the results and patient selection. In addition, the effect of interventions such as revascularisation or up-titration of anti-heart failure medical therapy could not be controlled for. A prospective evaluation of cryoablation outcomes in heart failure, including a comparison with RF ablation, should ideally be the focus of prospective randomised studies. It is hoped that these data might inform the design of such trials and provide a limited evidence base for those considering utilizing this approach clinically. The cut-off value of LVEF <45% may have introduced selection bias towards less severe phenotypes of heart failure, which may limit the applicability of the findings to patients with more severe LV dysfunction. Ongoing cardiac specific beta-blockade used as anti-failure therapy may have impacted upon AF recurrence.