Catheter ablation in heart failure
In recent years, a rapid succession of randomised clinical trials have established the role of catheter ablation as an effective anti-heart failure treatment in patients with concurrent AF and systolic dysfunction6, 8-12. Benefits have included improved quality of life, functional capacity10, ejection fraction6, reverse remodelling (both atrial13 and ventricular14), reduced hospitalisations8 and reduced mortality8, 12. However, these trials have exclusively utilised RF as the ablation strategy of choice. Whilst there is an increasing evidence base for the efficacy of cryoballoon ablation compared to RF ablation, in patients with paroxysmal AF and the absence of structural heart disease15, data regarding the use of cryoablation in the setting of AF and concurrent structural heart disease, and in particular in patients with systolic heart failure, is limited. Pruszkowska et al demonstrated the feasibility of cryoballoon ablation in 30 consecutive patients with LVEF ≤ 40% and continuous monitoring with CIEDs, and demonstrated improvements in NYHA class, EHRA class, AF burden and LVEF, compared to controls undergoing cryoablation without LV dysfunction16. Providencia et alcompared outcomes in patients with HF undergoing catheter ablation to those with structurally normal hearts from a multicentre registry and reported use of the cryoballoon in a significant proportion in both groups, suggesting the technique is used in these patients in clinical practice17. The present study is the first to demonstrate the efficacy in controlling AF over the long term with an index cryoballoon strategy. The success rates were, as expected, better for paroxysmal AF than for persistent and long standing persistent AF, with results similar to that reported for ablation with radiofrequency ablation in this setting. However, the multivariate analysis did not suggest that any particular group from this cohort fared particularly poorly with cryoablation.
This is also the first study to report on improving ventricular function following AF ablation with an index cryoablation strategy. The greater magnitude of improvement seen in patients with non-ischaemic cardiomyopathy compared to those with ischaemic (+13% vs +7%, p<0.001) is consistent with the findings of recent studies, suggesting that absence of fibrosis6 or structural heart disease7 can predict the extent of LV recovery. We await the outcome of a large multicentre study (CONTRA-HF; NCT03062241) which will directly compare cryoablation to medical therapy in patients with heart failure.