LAA occlusion during cardiac surgery beneficial in older patients with AF

Surgical left atrial appendage occlusion was linked to lower risk for readmission for thromboembolism at 3 years among older patients with atrial fibrillation undergoing concomitant cardiac surgery, according to data published in JAMA.

“Although oral anticoagulation is effective at reducing the risk of thromboembolic stroke, as few as half of all eligible patients use anticoagulation, frequently citing high perceived hemorrhage risk, cost and patient preference,” Daniel J. Friedman, MD, from the Duke Clinical Research Institute at Duke University School of Medicine, and colleagues wrote. “The low rates of anticoagulant use and the understanding that AF-related thrombus formation is most likely to occur in the LAA has led to increasing interest in occluding the LAA as a potential alternative to anticoagulation, particularly among those with difficulty tolerating anticoagulation.”

To evaluate whether surgical left atrial appendage (LAA) occlusion was associated with reduced risk for readmission for thromboembolism, Friedman and colleagues conducted a retrospective cohort study of a nationally representative Medicare-linked cohort from the Society of Thoracic Surgeons Adult Cardiac Surgery Database.

The study population consisted of 10,524 patients aged at least 65 years with AF who were undergoing cardiac surgery with or without concomitant surgical LAA occlusion.

The primary outcome was readmission for thromboembolism, as defined by Medicare claims data, up to 3 years after the procedure.

Secondary outcomes included hemorrhagic stroke, all-cause mortality and a composite endpoint of thromboembolism, hemorrhagic stroke or all-cause mortality.

Among patients undergoing surgery, 37% underwent surgical LAA occlusion.

At a mean follow-up of 2.6 years, the researchers found that thromboembolism occurred in 5.4% of patients, hemorrhagic stroke in 0.9%, all-cause mortality in 21.5% and the composite endpoint in 25.7%.

Improved outcomes

Patients who underwent surgical LAA occlusion had lower unadjusted rates of thromboembolism (4.2% vs. 6.2%), all-cause mortality (17.3% vs. 23.9%) and the composite endpoint (20.5% vs. 28.7%) compared with those who had no surgical LAA occlusion. However, no significant difference in rate of hemorrhagic stroke (0.9% vs. 0.9%) was observed.

After inverse probability-weighted adjustment, Friedman and colleagues found that surgical LAA occlusion conferred a significantly lower risk for thromboembolism (subdistribution HR = 0.67; 95% CI, 0.56-0.81), all-cause mortality (HR = 0.88; 95% CI, 0.79-0.97) and the composite endpoint (HR = 0.83; 95% CI, 0.76-0.91) but not hemorrhagic stroke (subdistribution HR = 0.84; 95% CI, 0.53-1.32).

Additionally, it was found that compared with no surgical LAA occlusion, surgical LAA occlusion was associated with a lower risk for thromboembolism among patients discharged without anticoagulation (unadjusted rate, 4.2% vs. 6%; adjusted subdistribution HR = 0.26; 95% CI, 0.17-0.4), but not among patients discharged with anticoagulation (unadjusted rate, 4.1% vs. 6.3%; adjusted subdistribution HR = 0.88; 95% CI, 0.56-1.39).

Guiding clinical practice

In a related editorial, Victor A. Ferraris, MD, PhD, from the department of surgery at the University of Kentucky, wrote the results represent a unique contribution, but data on which methods of surgical LAA occlusion were used would have been helpful.

“Importantly, these results suggest that failure to perform [surgical LAA occlusion] at the time of cardiac operation in patients with nonvalvular AF is associated with significantly increased intermediate-term thromboembolic risk in these patients,” he said. “The findings reported by Friedman and co-authors may help guide clinical practice and should serve to safer surgical approaches for AF treatment among patients who require cardiac operations.” – by Dave Quaile

Disclosures: Ferraris reports no relevant financial disclosures. Friedman reports that he receives grants from Abbott and Boston Scientific. Please see the study for all other authors’ relevant financial disclosures.