Afib patients benefit when left-atrial-appendage occlusion added to their heart surgery

Reuters Health - 17/05/2021 - Occluding the left atrial appendage when cardiac surgery is undertaken for other reasons can lower the risk of stroke by one-third in patients with atrial fibrillation, according to the results of a randomized clinical trial.

Most of the 4,770 participants, whether their appendage was occluded or not, received antithrombotic therapy, a treatment that is considered to reduce the risk of stroke by roughly two-thirds.

"There has been this longstanding tension between oral anticoagulation and this approach of occluding the left atrial appendage. This is the first trial and the first definitive evidence that surgical left-atrial-appendage occlusion reduces ischemic stroke risk. That has never been demonstrated before," said lead author Dr. Richard Whitlock of Hamilton General Hospital, in Canada.

"This trial shows (left-atrial-appendage occlusion) is effective on top of oral anticoagulation, which is wonderful," he told Reuters Health by phone. "We were surprised at how large the benefit was."

The findings of the study, known as LAAOS III, were reported at a meeting of the American College of Cardiology and by the New England Journal of Medicine.

The appendage, a small sac with no known function in adults, is a relic of embryonic cardiac development and considered a breeding ground for 90% of the clots in people with Afib. Afib patients, in turn, make up 2% to 3% of the general population and face a stroke risk that is four to five times higher than the general population. Closure is typically done in high-risk patients with nonvalvular Afib when drug therapy has failed or is not an option.

With a mean follow-up of 3.8 years, the rate of ischemic stroke or systemic embolism was 4.8% in the patients who had appendage occlusion added to their surgery versus 7.0% who did not (P=0.001).

All of the patients, from centers in 27 countries, were scheduled to receive cardiac surgery with cardiopulmonary bypass and ranked at least a 2 on a scale from 0 to 9 where a higher score indicated a greater risk of stroke. They were randomly assigned to undergo or not undergo occlusion of the left atrial appendage during surgery.

"If the patient has atrial fibrillation and is undergoing heart surgery for some other indication, the left atrial appendage should be occluded. Period," said Dr. Whitlock. "That should be standardized across the cardiac-surgery community, and that should enter into the guidelines."

Several closure methods were permitted, although percutaneous closure and purse-string closure were not.

The stroke reduction was seen after the first 30 days after surgery.

The researchers calculated that 37 Afib patients would need to undergo concomitant left atrial appendage occlusion to prevent one stroke over five years.

"The procedure caused minimal prolongation of bypass time and cross-clamp time and did not have a significant effect on death, hospitalization for heart failure, myocardial infarction, or bleeding," notes a linked editorial by Dr. Richard Page of the University of Vermont College of Medicine, in Burlington.

Rates of perioperative bleeding, heart failure and death were comparable in the two groups.

"Cardiac surgeons are going to be enthused by these results. The field of arrhythmia and cardiology are going to be ecstatic," predicted Dr. Whitlock, a cardiac surgeon at Hamilton and a professor of surgery at McMaster University. "This opens a new doorway to better treat our patients for stroke prevention."

The researchers caution that "without a trial that directly compares oral anticoagulation with left atrial appendage occlusion, it remains uncertain whether occlusion can replace anticoagulation."

SOURCES: https://bit.ly/3w4Npz3 and https://bit.ly/3fnrnka The New England Journal of Medicine, online May 15, 2021.

By Gene Emery



Posted on 17 May 202124 May 2021