Cryoblation as first-line treatment of new-onset atrial fibrillation?

European Heart Journal, Volume 42, Issue 16, 21 April 2021, Pages 1543-1544, Published: 24 March 2021


The European Society of Cardiology Guidelines for the diagnosis and management of AF3 recommend (Class IA) rhythm control therapy for symptom and quality of life improvement in symptomatic patients with AF. However, for rhythm control, catheter ablation is a Class IIA recommendation, according to the patient choice, which raises to Class IA in AF patients with heart failure with reduced ejection fraction and for failed drug therapy.

It is well known that AF is a progressive disease, with ectopic foci arising around pulmonary veins with further progression in the atrial wall. Thus, it is conceivable that early intervention aiming at rhythm control throughout bidirectional conduction block of all pulmonary veins might reduce the progression of the disease. Few and often underpowered trials have compared the effects of early radiofrequency ablation with antiarrhythmic drugs as first-line therapy, with conflicting and inconclusive results on AF recurrence.4 In the recently published EAST-AFNET-4 trial,5 early and comprehensive rhythm control strategy by ablation or antiarrhythmic drugs applied on the top of oral anticoagulation and rate control demonstrated better outcomes as compared to usual care in patients with recent-onset AF at 5.1 years of follow-up. Early rhythm control with all different modalities has demonstrated superiority in cardiovascular outcome and has not produced additional harm in terms of length of hospitalization and adverse events.6 However, heterogeneity of rhythm control choices among the 135 different participating centres, makes extrapolation of these promising results to a typical patient with early AF a challenging exercise.6

These two novel and similar trials consistently support a beneficial role of cryoballon ablation as early rhythm control strategy in new-onset AF, as compared to guideline-recommended first-line pharmacological treatment. However, the sample size of these trials may not have been large enough to allow the detection of relevant complications.1,2

While the results of STOP AF First2 should be interpreted with caution, since the arrhythmia detection plan does not appear sufficiently sensitive, EARLY-AF1 provides better demonstration of a greater efficacy of cryoablation in preventing symptomatic AF episodes in comparison to drug therapy. Furthermore, the recurrence of AF events was observed in ∼20–50% of the patients randomized to cryoablation. This suggests the need for a cost analysis. In fact, many patients with recurrences, especially if symptomatic, may require additional interventional procedures, which may impact on the cost of the disease management.

Despite the limited patient sample size, not powered to provide answers on clinically relevant complications, including relevant brain infarcts, and the open-label design, the current positive results might be considered encouraging. Longer follow-up and larger patient populations are required to define the beneficial role of early cryoablation in the prevention of the degenerative processes leading to AF later recurrences.

Finally, it should be underlined that both EARLY-AF1 and STOP AF First2 enrolled relatively young patients (mean age, 58 and 61 years, respectively), with normal left ventricular function, normal left atrial size, and few coexisting clinical conditions. This prevents an extension of the results to more ‘sick’ patients. Thus, radiofrequency potentially remains the standard of care in patients with enlarged and pathologic atria, in whom cryoballon might fail to reach the ablation sites. However, it is of note that cryoablation, based on the balloon inflation and application of low temperature in pulmonary veins, with no need for precise detection of ectopic sites, is a fast and relatively easy to perform procedure. Whether cryoablation can be proposed as a first-line treatment for selected patients with AF replacing antiarrhythmic drugs warrants further confirmation.

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