Prior Failed Catheter Ablation
Posterior wall isolation is part of the complex strategy of managing
advanced AF, in addition to PVI, however it is often difficult to
achieve safely with only endocardial catheter ablation. This is due to
the thickness of the roof of the posterior wall of the left atrium and
because of the need for long connection lines between the roof and the
floor of the atrium, to create the conduction block without a gap. The
lower linear lesion line at the floor of the posterior wall is more
difficult to create due to the proximity of the esophagus and risk of
esophageal damage.48 In
a study of patients undergoing left atrial posterior wall isolation
concomitant with pulmonary vein reisolation, feasibility of isolating
the LAPW with endocardial ablation was successfully demonstrated,
despite no outcome differences in improvement of freedom from atrial
arrhythymias compared to pulmonary vein reisolation alone. Of the 196 AF
patients in the study, 103 were in the LAPW plus PV reisolation group
and 36 patients (35%) required additional ablation within the center
“box” of the LAPW.49This brings increased risk to endocardial catheter ablation but has
potential to be easier and safer utilizing a Hybrid ablation approach
such as those with advanced AF presenting for repeat ablation treatment.
In patients with advanced AF and a need to isolate the posterior wall, a
hybrid ablation approach may have the advantage of better access to
completely and safely isolate it primarily through epicardial ablation
applying energy towards the heart followed by endocardial touchup to
address any gaps particularly near the pericardial reflections. This
provides a more comprehensive treatment to prevent recurrence resulting
from multiple triggers, including the pulmonary vein, left posterior
wall, and endocardial tissue.
While the CONVERGE trial excluded patients with prior ablations, in
routine clinical practice many patients with advanced AF have undergone
prior catheter ablation attempts yet are still experiencing AF
recurrences. A recent meta-analysis of Hybrid Convergent ablation
studies included three studies in which one-third of the total patients
had prior catheter ablation. Mannakkarra et al. recently reported their
single-center experience with Hybrid Convergent ablation, including 38%
of patients who had received prior catheter ablation at
baseline.20 However, to
date, only one study has directly compared outcomes of patients who
received Hybrid Convergent as a de novo versus previous catheter
ablation, finding there was no difference in arrhythmia
recurrence.22Additionally, there may be a cumulative benefit in that those with prior
ablations require less endocardial PV isolation and were more likely to
convert to sinus rhythm during the Hybrid procedure compared to those
with no prior ablation
history.22 Kress et al.
reported 75.0% of patients with prior ablation needed endocardial PV
isolation, which was significantly less than 97.9% of patients who
received hybrid ablation as a first ablation procedure
(p<0.001). Additionally, fewer patients who had prior ablation
needed cardioversions (26.7%) to achieve sinus rhythm intraprocedurally
compared to those receiving hybrid ablation as a first ablation
procedure (45.8%, p=0.038). With few comparative studies or studies
exclusively looking at hybrid convergent ablation after previous
catheter ablation patients, more research as well as additional
cumulative real-world evidence is necessary to determine whether there
are any significant differences in procedural and treatment
outcomes.19