Main findings
We conducted a single center, retrospective analysis of 1346 patients
undergoing index AF ablation, with a significant size female cohort in
the study population, to investigate gender differences in outcomes and
complications following catheter ablation of AF. We found that:
diagnosis-to-ablation time for both groups was similar; although the
number of EP appointments leading up to ablation was similar in men and
women, women tried and failed more AADs than men prior to ablation;
there were no gender-based differences in one-year arrhythmia recurrence
rates; and procedure-related complication rates between men and women
were similar.
Studies have shown that women with AF have a worse prognosis, including
an increased risk of stroke, heart failure, and death, as well as more
severe symptoms, a worse quality of life, and diminished functional
capacity (5). Despite these facts, women are less likely to receive
rhythm control through catheter ablation and cardioversion.
Consequently, women often undergo ablation procedures at an older age
and later in their disease course, often having experienced AF for a
longer period with advanced cardiac remodeling resulting from the
disease (5). While some studies suggest that females have a higher
post-ablation arrhythmia recurrence rate than males, other studies like
the CASTLE-AF trial did not show a gender difference in the
effectiveness of ablation procedures. There remains ambiguity regarding
gender-based differences in outcomes and complications related to AF
ablation, partly because of the underrepresentation of women in these
studies. Our study aimed to investigate gender-based disparities in the
management of AF and as well as the outcome and complication rate of AF
ablation procedures.
In contrast to most previous studies investigating gender impact on AF
ablation, our study included a relatively large cohort of patients with
a significantly higher proportion of female patients (n=450, 33.4% of
total study patients). In accordance with existing studies, women were
older at the time of ablation (66.2 vs 62.4 years; p<0.001).
Compared to their male counterparts, women also tried and failed more
anti-arrhythmic drugs before presenting for ablation procedure (1.13 vs
0.98; p=0.002). These results may indicate female patients’ apprehension
towards procedural intervention, referral bias, or some other delaying
factor. In contrast to previous studies (6), however, we found no
significant difference in the duration of AF between men and women from
initial diagnosis to ablation (44.6 months versus 44.1 m; p=0.97). At
the time of diagnosis, it was observed that 25.3% of female patients
had PersAF compared to 35.3% of male patients (p<0.001).
Similarly, at the time of ablation, 31.8% of female patients had PersAF
as opposed to 43.1% of male patients (p<0.001), suggesting a
similar rate of progression from paroxysmal to PersAF in both genders.
With regards to procedural success, we found no significant difference
in AF recurrence at 1-year post-ablation between male and female
patients (27.7% vs 30%; p=0.38). This is consistent with previous
studies (4,12,14) that have reported equal rates of procedural success
and low recurrence rates in both genders. We believe it is more likely
that the procedural results are primarily influenced by the consistency
in timing of ablation from the time of diagnosis, regardless of gender.
Timing of ablation is one of the major predictive factors of ablation
outcomes due to advancement of atrial substrate. The study by Bunch et
al. demonstrated that increasing time between diagnosis of atrial
fibrillation and catheter ablation adversely affects long-term outcomes
(20).
In prior research, it has been suggested that sex differences in
outcomes can be partly explained by women having more advanced AF
disease at the time of ablation (16). The prospective multicenter DECAAF
study found a linear relationship between the degree of atrial fibrosis
as identified by LGE-CMR and AF recurrence rates post-ablation (21) and
another study by Chelu and colleagues correlated higher levels of atrial
fibrosis with longer AF duration (22). Recent clinical trials EARLY- AF,
CASTLE-AF, STOP-AF strongly advocate for early rhythm control using
catheter ablation as a first line treatment for AF to reduce morbidity
and mortality (23,24,25). With the growing evidence for early ablation,
our study supports a uniform approach for all patients with regards to
early ablation. Given a greater tendency to use antiarrhythmic drug
therapy in women with AF, greater attention to counseling on therapeutic
choices may be needed in this population (5).
In addition, no gender-related differences were observed in procedural
complications, including vascular injury (7 males, 5 females; p=0.55),
phrenic nerve injury (1 male, 1 female), pericardial effusion (6 males,
7 females; p=0.12), esophageal fistula (0 males, 0 females), or
stroke/TIA (3 males, 1 female; p=0.71), supporting the recommendation
that both men and women should be offered catheter ablation for atrial
fibrillation on an equal basis. It should be acknowledged, however, that
unlike most other studies in this area (15), our population did not
demonstrate significant gender-based differences in the rates of
comorbidities such as diabetes, hypertension, heart failure, chronic
kidney disease, which may also be contribute to the lack of gender
differences in procedural complications.
One of the key gender disparities in the management of AF is in the use
of anticoagulation therapy. Studies have shown that women with AF are
less likely to receive anticoagulation therapy compared to men, despite
having similar or higher risk for stroke (3, 26). It is worth
emphasizing, however, that women in our study were adequately treated
with oral anticoagulants (92.2% females, 88.6% males; p=0.012), and
that may partly explain the reduction in neurological adverse events.