Women's Outcomes Post–AF Catheter Ablation Paradoxically Discordant

Patrice Wendling

July 29, 2016

PALO ALTO, CA — Women have more rehospitalizations for atrial fibrillation (AF) after catheter ablation but paradoxically are less likely than men to undergo subsequent rhythm-control strategies, according to a claims-based study described as the largest to examine AF procedural outcomes in the US by sex[1].

The unadjusted and adjusted risk of AF rehospitalization within a year of ablation was higher for women than men (13% vs 12%, adjusted hazard ratio [aHR] 1.12), as was risk of all-cause hospitalization (32% vs 27%, aHR 1.14).

Despite this, women were less likely to receive a repeat ablation (13% vs 15%, aHR 0.92) or cardioversion (17% vs 21%, aHR 0.75) (P<0.001 for all).

"These data call for greater examination of barriers and facilitators to sustain rhythm-control strategies in women," lead investigator Dr Daniel W Kaiser (Stanford University School of Medicine, CA) and colleagues write in their article published July 27, 2016 in JACC Clinical Electrophysiology.

They note that several factors may be at play, including the very real potential for women to have their cardiac symptoms and risk of heart disease downplayed by their doctors. Evidence also suggests that women with AF have a delayed referral pattern compared with men and fail more antiarrhythmic medications before catheter ablation.

"Delaying the time to ablation could promote a higher AF or comorbidity burden at the time of ablation, which may have resulted in more electrical and structural remodeling," they suggest.

Notably, women were older at baseline than men (61.9 vs 58.1 years, P<0.001) and had a higher prevalence of hypertension (66.2% vs 61.8%, P<0.001), diabetes (22.8% vs 20.7%, P=0.0007), prior stroke or transient ischemic attack (5.7% vs 3.5%, P<0.001), and anemia (13.6% vs 8.2%, P<0.001). Men had more prior MIs (4.5% vs 5.6%, P=0.001).

Women were also more likely to have received rate-control agents (70.6% vs 63%) and class I antiarrhythmics (28% vs 23.8%) but less likely to have been treated with amiodarone (13.9% vs 16%) or statins (24.4% vs 28.6%) (P<0.001 for all). Use of class III antiarrhythmics and oral anticoagulation was similar between sexes.

All 21,091 patients (6137 women, 14,954 men) had undergone AF catheter ablation from 2007 to 2011 and were identified in the Truven Health Analytics MarketScan and Medicare Supplemental databases.

30-Day Outcomes

In addition to determining sex differences in baseline characteristics and longer-term outcomes, the investigators also evaluated 30-day postprocedural complications based on hospital-discharge diagnoses or procedure codes used to manage a complication.

They found that women had a low but modestly higher risk of complications within 30 days: hematoma or hemorrhage (2.3% vs 1.6%, P=0.0007), perforation or tamponade (3.8% vs 2.9%, P=0.0003), and vascular complications (2.7% vs 2%, P=0.0007). Rates of stroke (<1%) and death (<0.01%) were low and similar between sexes.

"These findings are consistent with prior studies and confirm the increased procedural risk for women in our large study population, which is representative of most patients receiving AF ablation today," Kaiser writes.

He points out several limitations of the study, including unidentified confounders and the inability to measure differences in AF recurrence, AF burden, or quality of life, "which are the key end points used in randomized trials of ablation," and the inability to classify AF severity, AF duration prior to ablation, heart-failure severity, or ejection fraction from the administrative data.

It is also unclear from the data whether women were less likely to be offered rhythm-control strategies or if they were more likely to refuse the procedures.

"The underlying motivations driving clinical decision making are complex and may vary by gender," Kaiser and colleagues write, noting that a single-center Japanese study suggested women were more likely to refuse catheter ablation.

"In context, these data highlight the importance of communication between patients and clinicians to ensure that fears, motivations, and perspectives of patients and caregivers are adequately addressed in order to deliver optimal and patient-centered care."

The authors report no relevant financial relationships. Dr Kaiser is supported by a grant from the National Heart, Lung, and Blood Institute. Disclosures for the other authors are listed in the article.

Follow Patrice Wendling on Twitter: @pwendl. For more from theheart.org, follow us on Twitter and Facebook.


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