From the Journals

Surgical LAA occlusion tops anticoagulation for AF thromboprotection



Surgical left atrial appendage occlusion may be just as good as anticoagulation at preventing thromboembolic events in older people with atrial fibrillation, with less risk of bleeding into the brain, according to a database review of more than 10,000 patients.

Among elderly atrial fibrillation patients who underwent heart surgery with no oral follow-up oral anticoagulation, those who had the left atrial appendage surgically occluded were 74% less likely than were those who did not to be readmitted for a major thromboembolic event within 3 years, and 68% less likely to be readmitted for a hemorrhagic stroke, researchers at Duke University in Durham, N.C., found.

“The current study demonstrated that S-LAAO [surgical left atrial appendage occlusion] was associated with a significantly lower rate of thromboembolism among patients without oral anticoagulation. In the cohort of patients discharged with oral anticoagulation, S-LAAO was not associated with [reduced] thromboembolism but was associated with a lower risk for hemorrhagic stroke presumably related to eventual discontinuation of oral anticoagulation among S-LAAO patients,” reported Daniel Friedman, MD, and his coinvestigators. The study was published Jan. 23 in JAMA.

In short, the findings suggest that shutting down the left atrial appendage in older patients offers the same stroke protection as anticoagulation, but without the bleeding risk. Given the low rates of anticoagulant use, physicians have been considering that approach for a while. Even so, it’s only been a weak (IIb) recommendation so far in AF guidelines because of the lack of evidence.

That might change soon, but “additional randomized studies comparing S-LAAO without anticoagulation [versus] systemic anticoagulation alone will be needed to define the optimal use of S-LAAO,” said Dr. Friedman, a cardiothoracic surgeon at Duke, and his colleagues. Those studies are in the works.

The team found 10,524 older patients in the Society of Thoracic Surgeons Adult Cardiac Surgery Database during 2011-2012, and linked them to Medicare data so they could be followed for up to 3 years. About a third of the subjects had stand-alone coronary artery bypass grafting; the rest had mitral or aortic valve repairs with or without CABG.

The investigators compared outcomes among the 37% (3,892) who had S-LAAO with outcomes among those who did not. Participants were a median of 76 years of age, 61% were men, and they were all at high risk for AF stroke.

After a mean follow-up of 2.6 years, subjects who received S-LAAO without postoperative anticoagulation had a significantly lower risk of readmission for thromboembolism – stroke, transient ischemic attack, or systemic embolism – compared with those who received neither S-LAAO nor anticoagulation (unadjusted rate 4.2% versus 6.0%; adjusted subdistribution hazard ratio [sHR] 0.26, 95% CI, 0.17-0.40, P less than .001).

There was no extra embolic stroke protection from S-LAAO in patients who were discharged on anticoagulation (sHR 0.88, 95% CI, 0.56-1.39; P = .59), but the risk of returning with a hemorrhagic stroke was considerably less (sHR 0.32, 95% CI, 0.17-0.57, P less than .001).

The S-LAAO group more commonly had nonparoxysmal AF, a higher ejection fraction, a lower mortality risk score, and lower rates of common stroke risks, such as diabetes, hypertension, and prior stroke. The Duke team adjusted for those and a long list of other confounders, including smoking, age, preoperative warfarin, and academic hospital status.

There were important limitations. No one knows what surgeons did to close the LAA, or how well it worked, and most patients discharged on anticoagulation were sent home on warfarin, not the newer direct oral anticoagulants.

The investigators noted that “the strongest data to date for LAAO come from randomized trials comparing warfarin with percutaneous LAAO using the WATCHMAN device” from Boston Scientific.

The reduction in cardiovascular mortality in those trials appeared to be driven by a reduction in hemorrhagic stroke and occurred despite increased rates of ischemic stroke, they said.

The current study, however, showed that S-LAAO was associated with a significantly lower rate of thromboembolism in patients without oral anticoagulation, the authors said.

The work was funded, in part, by the Food and Drug Administration. Dr. Friedman reported grants from Boston Scientific and Abbott. Other authors reported financial relations with those and several other companies.

SOURCE: Friedman DJ, et. al. JAMA. 2018;319(4):365-74. doi: 10.1001/jama.2017.20125.

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