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.