Surgical closure of LAA reduces the risk of AF stroke by one-third


Left atrial appendage occlusion performed at the time of another heart surgery reduces the risk of stroke by approximately one-third in high-risk patients atrial fibrillation (AF), according to the results of the occlusion study of the left atrial appendix (LAAOS III).

At 3.8 years of follow-up, the main end goal of ischemic stroke or systemic embolism occurred in 4.8% of patients randomly assigned to LAAO and in 7.0% of those who had no occlusion. This resulted in a 33% reduction in relative risk (risk ratio) [HR], 0.67; 95% CI: 0.53-0.85; Pg = .001).

In a baseline analysis, the effect was present at first, but was more pronounced after the first 30 days, reducing the relative risk by 42% (HR, 0.58; 95% CI, 0.42 – 0.80), according to the researchers.

The reduction in the risk of continuous stroke was greater than oral anticoagulation (OAC) and consistent across all subgroups, according to Richard Whitlock, MD, professor of surgery at McMaster University, Hamilton, Ontario, Canada, in a last-minute trial. 15 al Scientific session of the American College of Cardiology (ACC) 2021.

Dr. Richard Whitlock

The procedure was safe and added, on average, only 6 minutes to the cardiopulmonary bypass time, according to the results, simultaneously published at the New England Journal of Medicine.

“Any patient who comes to the operating room that fits the profile of a LAAOS III patient, so that they have atrial fibrillation and a high risk of stroke based on their CHA2DS2-VASc score: the appendix should come off, “he said | Cardiology Medscape.

Commenting during the formal discussion, panelist Michael J. Mack, MD, Baylor Health Care System, Houston, Texas, said, “This is a study that can change game and can change practice,” but asked if there is patients who should not. they submit to LAAO, like the ones they have heart attack (HF).

Whitlock said that between 10% and 15% of patients undergoing cardiac surgery have a history of AF and “as surgeons, therapy needs to be individualized. If you have a very fragile patient, you have concerns about tissue quality. , you really need to think about how the left atrial appendix would be closed or whether it would be obtained “.

Reassuringly, he noted, the data show no increase in hospitalizations for HF and a beneficial effect on stroke between patients with HF and those with low ejection fractions, below 50%.

Observational data on surgical occlusion have been inconsistent and current guidelines offer a weak recommendation in patients with AF who have a contraindication to long-term anticoagulation. This is the first study to definitively show that ischemic stroke is reduced by managing the left atrial appendix, he said. | Cardiology Medscape.

“Previous percutaneous trials did not prove this; they showed no inferiority, but it was driven primarily to prevent bleeding events or stroke by removing patients from oral anticoagulation,” he said.

The results should translate into a Class I guideline recommendation, he added. “This opens up a new treatment paradigm for atrial fibrillation and stroke prevention as it is actually the first study that has analyzed the additive effects of left atrial appendix management in addition to oral anticoagulation, and is protective in addition to oral anticoagulation. That means a paradigm shift. “

In an accompaniment editorial, Richard L. Page, MD, University of Vermont, in Burlington, said the trial does not provide any information on the possible benefit of surgical occlusion in patients who cannot receive anticoagulation or with lower CHA.2DS2-VASc score, but accepted a class I recommendation is likely for the population studied.

“I hope and anticipate that the results of this paper will strengthen the guidelines guidelines for surgical occlusion of the left atrial appendix and increase the number of cardiac surgeons who routinely perform this complementary procedure,” he said. “While many already perform this procedure, cardiac surgeons should feel more comfortable that the surgical occlusion of the left atrial appendix is ​​indicated and supported by high-quality random data.”

Unfortunately, LAAO III does not answer the question of whether patients can get rid of anticoagulation, but it does show that surgical occlusion provides additional protection against strokes, which can be huge with atrial fibrillation, Whitlock said.

“Today I spoke to a patient who is a 66-year-old active individual with a DOAC and his risk of stroke has been further reduced from 30% to 40%, so he was ecstatic to hear the results, ”Whitlock said. “I think it’s quiet.”

Global, non-industrial effort

LAAOS III researchers from 105 centers in 27 countries enrolled 4811 heart surgery patients (mean age, 71 years; 68% men) who had CHA2DS2-Basque score of 2 or more.

In total, 4770 were randomly assigned to any LAAO or occlusion using the preferred amputation technique with suture closure of the stem, as well as stapler occlusion or epicardial device closure with the AtriClip (AtriCure) o TigerPaw (Medical Model). The treatment team, researchers, and patients were not blinded.

Patients were followed every 6 months with a validated stroke questionnaire. The data security control board stopped the trial shortly after the second interim review.

The average CHA2DS2-The VASc score was 4.2, one-third of patients had permanent AF, 9% had a history of stroke, and more than two-thirds underwent a valve procedure, making LAAOS III unique, as many previous trials on AF ruled out valvular AF, Whitlock noted.

The operating results of the LAAO groups and no LAAO groups were as follows:

  • Referral time: average, 119 minutes vs 113 minutes

  • Cross-clamp time: average, 86 minutes vs 82 minutes

  • Chest outlet: average, 520 ml vs 500 ml

  • Bleeding reintervention: both, 4.0%

  • Prolonged hospitalization for HF: between 5 and 14 events

  • Mortality at 30 days: 3.7% vs 4.0%.

The primary safety outcome of hospitalization for HF for 3.8 years occurred in 7.7% of patients with LAAO and 6.8% without occlusion (HR, 1.13; 95% HF, 0 , 92 – 1.40), despite concern that removal of the appendix could worsen the risk of HF due to impaired renal salt and water clearance.

“There’s observational data on both sides of the fence, so it was an important endpoint that people were worried about,” Whitlock said. Medscape. “We had a data collection company dedicated to admission for heart failure to actually cause it, and in the end we didn’t see any adverse effects.”

Although ischemic stroke rates at 3.8 years were lower with LAAO than without (4.2% vs. 6.6%; HR, 0.62; 95% CI, 0.48 – 0, 80), there were no differences in systemic embolism (0.3% for both) or in death (22.6% versus 22.5%).

In LAAOS III, less than 2% of deaths were attributed to a stroke, which is consistent with large stroke records, Whitlock said. “Stroke is not what causes people with atrial fibrillation to die; it is actually progression to heart failure.”

The positive effect on stroke was constant in all subgroups, including sex, age, rheumatic heart disease, baseline OAC type, ACC2DS2-VASc score (≤4 vs> 4), type of surgery, history of heart failure or hypertension, and previous stroke /transient ischemic attack/ systemic embolism.

Panelist Anne B. Curtis, MD, of Buffalo University, New York, expressed surprise that approximately half of the patients at baseline did not receive anticoagulation and questioned whether event rates varied among those who they remained in OAC and did not stay.

Whitlock noted that OAC is often underused in AF and that analyzes showed that the effects were consistent whether or not patients had anticoagulants.

Panelist Valentin Fuster, MD, a doctor at Mount Sinai Hospital in New York City, said LAAOS III is a “fantastic study, especially considering 27 countries, this is not easy.”

He suggested, however, that the 7% stroke rate in the control group was “quite high” when there are so many patients receiving OAC. Whitlock responded that the annual rate of events in tests such as RE-LY i AVERROES among similar patients it was approximately 1.5% to 2.5%, “so I think our results are consistent with other trials.”

The study was sponsored by the Population Health Research Institute (McMaster University). Whitlock and Fuster did not report relevant disclosures. Curtis reported fees and fees from consultants at Abbott, Janssen, Medtronic, Milestone Pharmaceuticals and Sanofi Aventis and the participation of the data security supervisory board by Medtronic.

N Engl J Med. Published online May 15, 2021. Summary, Editorial

Scientific Session of the American College of Cardiology (ACC) 2021. Abstract 402-12. Filed May 15, 2021.

Follow Patrice Wendling on Twitter: @pwendl. Follow ACC.21 coverage from | Medscape cardiology activated Twitter i Facebook.

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