Comparative Effectiveness of LAAO vs Oral Anticoagulation According to Sex
abstract
This abstract is available on the publisher's site.
Access this abstract nowBACKGROUND
The comparative real-world outcomes of older patients with atrial fibrillation (AF) treated with anticoagulation compared with left atrial appendage occlusion (LAAO) may be different from those in clinical trials because of differences in anticoagulation strategies and patient demographics, including a greater proportion of women. We sought to compare real-world outcomes between older patients with AF treated with anticoagulation and those treated with LAAO by sex.
METHODS
Using Medicare claims data from 2015 to 2019, we identified LAAO-eligible beneficiaries and divided them into sex subgroups. Patients receiving LAAO were matched 1:1 to those receiving anticoagulation alone through propensity score matching. The risks of mortality, stroke or systemic embolism, and bleeding were compared between matched groups with adjustment for potential confounding characteristics in Cox proportional hazards models.
RESULTS
Among women, 4085 LAAO recipients were matched 1:1 to those receiving anticoagulation; among men, 5378 LAAO recipients were similarly matched. LAAO was associated with a significant reduction in the risk of mortality for women and men (hazard ratio [HR], 0.509 [95% CI, 0.447-0.580]; and HR, 0.541 [95% CI, 0.487-0.601], respectively; P<0.0001), with a similar finding for stroke or systemic embolism (HR, 0.655 [95% CI, 0.555-0.772]; and HR, 0.649 [95% CI, 0.552-0.762], respectively; P<0.0001). Bleeding risk was significantly greater in LAAO recipients early after implantation but lower after the 6-week periprocedural period for women and men (HR, 0.772 [95% CI, 0.676-0.882]; and HR, 0.881 [95% CI, 0.784-0.989], respectively; P<0.05).
CONCLUSIONS
In a real-world population of older Medicare beneficiaries with AF, compared with anticoagulation, LAAO was associated with a reduction in the risk of death, stroke, and long-term bleeding among women and men. These findings should be incorporated into shared decision-making with patients considering strategies for reduction in AF-related stroke.
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Additional Info
Disclosure statements are available on the authors' profiles:
Comparative Effectiveness of Left Atrial Appendage Occlusion Versus Oral Anticoagulation by Sex
Circulation 2023 Feb 14;147(7)586-596, EP Zeitler, S Kearing, M Coylewright, D Nair, JC Hsu, D Darden, AJ O'Malley, AM Russo, SM Al-KhatibFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Randomized clinical trials notoriously enroll patients who may not be representative of patients seen in clinical practice, and enrollment of women in such trials has generally been suboptimal. The latter is true of randomized clinical trials of left atrial appendage occlusion (LAAO) devices in which women comprised only about 30% of the enrolled patients. Therefore, the current study’s investigators sought to assess the comparative effectiveness of LAAO devices versus oral anticoagulation by sex in older real-world patients with atrial fibrillation (AF). The study analyzed Medicare claims data from 2015 to 2019 to identify beneficiaries eligible for an LAAO device and examined the results for women and men. Outcomes of interest were all-cause mortality, stroke or systemic embolism, and bleeding. Robust statistical methods were used, including propensity score matching of patients undergoing LAAO device implantation in a 1:1 ratio to patients treated with an oral anticoagulant, and further adjustments were applied for residual differences between the two groups using Cox proportional hazards models. A total of 4085 women who received an LAAO device were matched to 4085 women treated with anticoagulation, and 5378 men who received an LAAO device were matched to 5387 men treated with anticoagulation. The authors found that the LAAO device was associated with a significantly lower risk of mortality for women (HR, 0.509; 95% CI, 0.447–0.580) and men (HR, 0.541; 95% CI, 0.487–0.601) and stroke or systemic embolism (HR, 0.655 for women, and 0.649 for men; P < .0001). LAAO recipients had a higher risk of bleeding early after implantation, but the risk was lower after the 6-week periprocedural period elapsed for both sexes. Strengths of the study include providing data on nonclinical trial patients, the large sample size, having a good representation of women, and the rigor of the data analyses. The study also provides helpful information on the type of anticoagulants used by Medicare beneficiaries with a surprisingly high use of vitamin-K antagonists (50%) and the high risk of mortality, stroke, and bleeding in these patients. The authors comprehensively acknowledged the potential limitations of their study especially regarding the fact that no statistical methods can fully adjust for selection bias and confounding factors, the fact that the results may not apply to younger patients, and the lack of data on some important clinical factors including but not limited to AF burden and the extent of cardiac remodeling. The finding of a lower risk of mortality in the LAAO group is unexpected and likely reflects residual selection bias and confounders, including the closer monitoring of patients in the periprocedural and follow-up periods that may have led to improved outcomes of recipients of the LAAO device. It should be noted, however, that recipients of the LAAO device had a higher burden of comorbidities than patients receiving an anticoagulant, which should have biased the results toward a smaller or no difference in outcomes between the two groups. Importantly, the authors highlight that their findings are associations and do not imply causality. Notwithstanding the limitations of this study, the results are helpful in complementing data from randomized clinical trials in informing shared decision–making encounters with patients, a Centers for Medicare and Medicaid Services requirement prior to implanting LAAO devices in Medicare beneficiaries.