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.