Atrial Fibrillation Treated With LAA Occlusion Reduces Thromboembolism Risk

left atrial appendage clot
left atrial appendage clot
Surgical left atrial appendage occlusion is associated with a lower risk for thromboembolism-related hospital readmission in older patients with atrial fibrillation who undergo cardiac surgery.

Surgical left atrial appendage occlusion (S-LAAO) is associated with a lower risk for 3-year thromboembolism-related hospital readmission compared with no S-LAAO in older patients with atrial fibrillation (AF) undergoing cardiac surgery, according to findings from a retrospective study published in the Journal of the American Medical Association.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database provided data from 10,524 patients with AF aged ≥65 years who underwent coronary artery bypass grafting (CABG) surgery, aortic valve surgery with or without CABG, or mitral valve surgery with or without CABG. Patients undergoing concomitant S-LAAO (n=3892) were compared with patients not undergoing the procedure (n=6632). The primary outcome was rehospitalization for thromboembolism at 3-year follow-up.

At follow-up (mean 2.6 years), thromboembolism had developed in approximately 5.4% of patients. In addition, 21.5% of patients died and hemorrhagic stroke had occurred in 0.9%. Overall, 25.7% of patients experienced the composite end point of thromboembolism, hemorrhagic stroke, or all-cause mortality by 3 years.

Lower absolute rates of all-cause mortality (17.3% vs 23.9%), thromboembolism (4.2% vs 6.2%), and composite end point (20.5% vs 28.7%) were observed in the S-LAAO vs no S-LAAO groups, respectively. The researchers observed significantly lower thromboembolism rates among the S-LAAO arm vs no concomitant intervention following inverse probability-weighted adjustment (subdistribution hazard ratio [HR], 0.67; 95% CI, 0.56-0.81; P <.001). Additionally, all-cause mortality (HR, 0.88; 95% CI, 0.79-0.97; P =.001) and composite end point (HR, 0.83; 95% CI, 0.76-0.91; P <.001) were significantly lower in patients receiving S-LAAO.

Similar to the unadjusted findings, there was no difference between the groups in terms of hemorrhagic stroke (subdistribution HR, 0.84; 95% CI, 0.53-1.32; P =.44). Patients initially discharged without anticoagulation therapy who subsequently underwent S-LAAO also had lower rates of thromboembolism compared with patients who did not receive S-LAAO (unadjusted rate, 4.2% vs 6.0%; adjusted subdistribution HR, 0.26; 95% CI, 0.17-0.40; P <.001). Conversely, no difference was observed between individuals who had S-LAAO and those who did not have S-LAAO who were initially discharged with anticoagulation medication (unadjusted rate, 4.1% vs 6.3%; adjusted subdistribution HR, 0.88; 95% CI, 0.56-1.39; P =.59).

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This was a nonrandomized retrospective trial, and the researchers of this analysis were unable to account for the reasoning behind certain treatment decisions made for each patient. In addition, because this study evaluated patients aged ≥65 years, it is unknown whether these findings can be generalized to a younger cohort of patients.

As supported by the findings from this study, the low adherence to anticoagulants “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.”

Reference

Friedman DJ, Piccini JP, Wang T, et al. Association between left atrial appendage occlusion and readmission for thromboembolism among patients with atrial fibrillation undergoing concomitant cardiac surgery. JAMA. 2018;319(4):365-374.