Advanced AF
In addition to the CONVERGE post-hoc analysis for LSPAF, other studies
have demonstrated favorable success to eliminate atrial arrhythmia or
maintain normal sinus rhythm in patients with longstanding persistent
AF.23,29Classification of AF by duration alone is arbitrary and can be
challenging based on incomplete patient history or available rhythm
monitoring. There is emerging evidence that other factors associated
with advanced AF may characterize patients who could benefit from Hybrid
Convergent
ablation.23,29
Left atrial (LA) size has been shown to be related to the recurrence of
AF after endocardial
ablation.30 Most
studies have defined enlargement by atrial diameter although a
meta-analysis of 22 studies that due to the asymmetry of the LA and thus
LA dilation, LA diameter may be an underestimate of size and LA volume
is more accurate in predicting AF recurrence and even new onset
AF.31 Because the
imaging modalities vary in the precision of their estimates of left
atrial size, the mean difference in larger atria associated with the
risk of AF is actually quite small so this must be a consideration in
determining the accuracy of LA size measurements. Of the 22 studies in
the meta-analysis by Zhuang, et al, the mean LA diameter reported at
baseline was 34.3-49mm, partly beyond normal range. Only 3 studies were
identified that solely examined non-paroxysmal AF, for a total of 143
patients. The mean atrial size in those studies ranged from
45-49mm.30 The CONVERGE
trial allowed patients with left atrial diameter up to 6.0 cm, with the
mean left atrial diameter in the Hybrid Convergent arm of 4.4 cm
(44mm).32 With an
increased risk of developing recurring AF, patients with enlarged left
atria might be best served by Hybrid Convergent ablation versus a
catheter ablation that may result in recurrences and repeat ablations.