Cryoballoon ablation for paroxysmal atrial fibrillation: mid-term
outcome evaluated by ECG monitoring with an implantable loop recorder.
Abstract
BACKGROUND The success rate after cryoballoon ablation (CB-A) performed
for paroxysmal atrial fibrillation (PAF) might be underestimated by
traditional noninvasive monitoring techniques. The purpose of this study
was to evaluate the mid-term outcome of CB-A in patients with PAF
implanted with an implantable loop recorder (ILR) after the procedure.
METHODS Between January 2017 and March 2019, all patients who underwent
CB-A for PAF and who were subsequently implanted with an ILR were
retrospectively included. All devices were equipped with remote
monitoring. All ILR-documented atrial tachycardia (AT) or AF episodes ≥
6 minutes were considered as recurrence; both true and false episodes
were collected. A 3-month post-procedural blanking period (BP) was
applied. RESULTS A total of 102 patients (77 male, mean age 60.6 ± 9.6
years) who underwent pulmonary vein isolation (PVI) by CB-A were
included; mean time from first diagnosis of AF to PVI was 51.5 ± 46.9
months. Mean follow-up was 29.3 ± 8.1 months; at 12-month follow-up, the
success rate was 64.7%, while at 2-year follow-up, freedom from AT/AF
recurrences was achieved in 44.1% of the patients. In the follow-up, a
total of 4987 ECG strips were analyzed; true-positive episodes were
confirmed in 2026 cases (40.6%), while 2961 episodes (59.4%) were
considered false-positive. CONCLUSION In patients with PAF implanted
with an ILR, CB-A results in freedom from any AT/AF recurrence in 64.7%
of patients at 12-month follow-up and in 44.1% of patients when
evaluated at 2-year. Careful adjudication of all ILR-documented AF
episodes is required to avoid misdiagnosis.