LAAC devices can cut stroke risk by one-third
Another LAAC trial showed a 33% lower ischemic stroke rate in patients who had their LAAs surgically occluded during surgery for other cardiac issues, giving real-life evidence to what had up to now been a theory.
That was after a median follow-up of 3.8 years. After the first 30 days following the procedure, patients who received LAAO were 42% less likely to suffer a stroke over long-term follow-up than those who did not receive LAAO. The trial was stopped early due to the strength of the observed benefits from the procedure.
Researchers in LAAOS III enrolled 4,811 patients undergoing heart surgery at 105 centers in 27 countries. About two-thirds of the trial participants underwent valve surgery, and 20% underwent coronary artery bypass graft surgery.
All the patients had documented AFib or atrial flutter and a CHA₂DS₂-VASc score of two or higher, indicating an elevated risk of stroke. Half of the participants were randomly assigned to receive LAAO at the time of their heart surgery. All patients received standard blood-thinning medication to reduce the risk of harmful clots after surgery. The multicenter, randomized LAAOS III trial included 2,379 participants in the occlusion group and 2,391 in the no-occlusion group, with a mean age of 71 years and a mean CHA2DS2-VASc score of 4.2. On a scale from 0 to 9, higher scores indicate a greater risk of stroke.
The participants had been scheduled to undergo cardiac surgery for another indication. They were randomly assigned to undergo or not undergo occlusion of the left atrial appendage during surgery, according to the results, published in the New England Journal of Medicine; all the participants were expected to receive usual care, including oral anticoagulation, during follow-up.
“This study confirms a new paradigm for stroke prevention for patients with atrial fibrillation,” said Dr. Richard Whitlock, a cardiac surgeon at McMaster University in Ontario, Canada, and the study’s lead author, in a news release. “The additive benefit of surgical LAAO on top of blood thinners has now been proven. There is no question that patients who are undergoing heart surgery and have elevated stroke risk and atrial fibrillation should have their atrial appendage occluded in their cardiac surgery.”
Strokes occurring soon after surgery typically have causes beyond AFib, such as calcium from blood vessels; thus, the true impact of LAAO on the risk of stroke from AFib is best seen after that early period, Whitlock said.
The results were consistent across all subgroups analyzed, with LAAO bringing the same benefits regardless of geographic location, sex, age, type of AFib, type of blood thinner used or other variables. On average, the procedure added less than 10 minutes to the heart surgery and demonstrated safety both in the short and long term.
“We were ecstatic to see these results,” Whitlock said. “This trial opens a new option for treatment of these patients by layering a mechanical approach —occlusion — on top of a medical approach. Instead of a tension between anticoagulation and occlusion, we need to start thinking about using these as additive approaches when patients are at high risk for stroke. This is a procedure that’s done once, and it keeps giving a benefit over time. This is going to prevent thousands of strokes.”
The study’s main funding sources were the Canadian Institutes of Health Research and the Heart and Stroke Foundation of Ontario.