Abstract
Introduction: A hybrid convergent approach (endocardial and
epicardial ablation) demonstrated superior effectiveness in a recent
randomized study for long-standing persistent atrial fibrillation
(LSPAF). Yet, there is a lack of real-world, long-term evidence as to
which patients are best candidates for a hybrid convergent approach
compared to standard endocardial cryoballoon pulmonary vein isolation
(CB PVI).
Methods and Results: This single-center, retrospective analysis
spanning from 2010 to 2015 compared two distinctly different atrial
fibrillation (AF) cohorts; one treated with stand-alone cryoablation and
one treated with a hybrid convergent approach. Baseline characteristics
described candidates for each approach. The following criteria were
utilized to determine CB PVI candidacy: 1) paroxysmal AF (PAF) with
failed class I/III antiarrhythmic drug (AAD) or 2) persistent/LSPAF with
failed class I/III AAD unwilling to undergo hybrid procedure. Selection
criteria for the hybrid procedure included: 1) PAF refractory to both
class I/III AAD and prior CB PVI or 2) persistent/LSPAF with failed
class I/III AAD agreeable to hybrid procedure. Prior sternotomy was
excluded. Serial electrocardiograms and continuous monitoring evaluated
primary efficacy outcome of time-to-first recurrence of atrial
arrhythmia after a 90-day blanking period. Secondary outcomes were
procedure-related complications and AAD use (at discharge, 12, and 36
months). Kaplan-Meier methods evaluated arrhythmia recurrence. Of 276
patients, 197 (64.2 ± 10.6 years old; 66.5% male; 74.1% PAF; 18.3%
persistent AF; 1.0% LSPAF; 6.6% undetermined) underwent CB PVI and 79
(61.4 ± 8.1 years old; 83.5% male; 41.8% PAF; 45.5% persistent AF;
12.7% LSPAF) underwent hybrid procedure. Arrhythmia freedom through 36
months was 55.2% for CB PVI and 50.4% for hybrid (p =0.32). Class I
AAD utilization at discharge occurred in 38 (19.3%) patients in the CB
PVI group and 5 (6.3%) patients in the hybrid group (p=0.01). CB PVI
class I AAD utilization at 12 months occurred in 14 (9.0) patients
versus 0 patients for hybrid convergent (p=0.004). Patients with one or
more adverse event were as follows: two (1.0%) in the CB PVI group
(both transient phrenic nerve palsy) and three (3.7%) in the hybrid
group (two with significant bleeding and one with wound infection)
(p=0.14).
Conclusion: This study demonstrated that patients with more
complex forms of AF (PAF refractory to both AAD and index endocardial
ablation or persistent/LSPAF) could be well managed with a convergent
approach. Moreover, outcomes match safety and efficacy thresholds
achieved by patients with an early, less complex AF etiology treated by
CB PVI alone.
Keywords: Atrial Fibrillation, Convergent Procedure,
Cryoballoon Ablation