Introduction
Atrial fibrillation (AF) is the most common sustained cardiac
arrhythmia, with prevalence estimates increasing globally over the last
decade.[1] Patients
with AF have significant morbidity and mortality secondary to symptoms
detrimental to quality-of-life, hemodynamic compromise, and embolic
stroke.[1,2] Many
treatment modalities have been used to reduce the global burden of this
disease, including antiarrhythmic drugs (AADs), catheter-based ablation,
and surgical ablation (SA).
While relatively ubiquitous in clinical practice, medical management
with AADs has had poor efficacy and has been associated with significant
adverse side
effects.[3–6]
Given advances in percutaneous interventional techniques, catheter-based
ablations have been utilized more frequently, and have had excellent
success rates, particularly in patients with paroxysmal
AF.[6] However, even the
best outcomes in published series have only shown 52% freedom from AF
at 10 years.[7] In
addition, these studies have shown that patients with long-standing
persistent AF tend to have inferior freedom from recurrent atrial
tachyarrhythmias (ATAs) when compared to those patients with paroxysmal
AF.[6–10]
The Cox-Maze procedure was introduced in 1987, and was the first
successful interventional treatment for
AF.[11] Since then, a
multitude of different surgical techniques have been developed,
utilizing a variety of lesion sets and ablation technologies. However,
the most-effective SA technique has remained the Cox-Maze
procedure.[11] While
initial “cut-and-sew” iterations of this technique were time-intensive
and complex due to need to create multiple incisions in the atrial
myocardium, the introduction of bipolar radiofrequency ablation and
cryoablation has simplified the procedure
significantly.[12] This
has led to the development of the Cox-Maze IV procedure
(CMP-IV).[13,14]
The CMP-IV has excellent efficacy as shown by our group and
others[15–17],
with 77% freedom from ATAs at 10
years[18]. The late
survival benefit associated with concomitant CMP-IV has also been
well-established.[19]
Most importantly, it has sharply reduced both operative times and
complication rates, leading to more widespread adoption of surgical
ablation, particularly in patients referred for concomitant cardiac
surgery.[12,19,20]
While used most commonly in the setting of other concomitant cardiac
surgery (e.g. mitral valve repair or replacement), the Cox-Maze IV has
been shown to be efficacious and safe as a stand-alone
procedure.[21,22]
Our group has previously shown equal efficacy of the stand-alone CMP-IV
in restoring sinus rhythm (SR) amongst patients with paroxysmal and
non-paroxysmal AF at early follow-up. Few studies have described
outcomes at late follow-up in sizable cohorts of
patients.[21–23]
This study examined our early-, mid-, and late-term outcomes of the
stand-alone CMP-IV amongst 174 consecutive patients with long-standing
persistent AF. This group was selected for analysis because it is
recognized to be the most difficult to treat, and it is the most
commonly referred for surgical
ablation.[15]