Left atrial appendage occlusion tied to less afib bleeding, mortality vs DOACs

Reuters Health -  12/01/2021 - Patients with atrial fibrillation (AF) who undergo left atrial appendage occlusion (LAAO) have similar odds of stroke as patients managed with direct-acting oral anticoagulants (DOACs) but a lower risk of major bleeding and mortality, a matched cohort study suggests.

"The results suggest LAAO to be superior to DOAC in AF patients who have a predicted high risk of stroke and bleeding and adds to the evidence that LAAO is a promising stroke prevention strategy in selected AF patients," Dr. Jens Erik Nielsen-Kudsk of Aarhus University Hospital in Denmark told Reuters Health by email.

As reported in JACC: Cardiovascular Interventions, Dr. Nielsen-Kudsk and colleagues compared 1,078 patients with AF who had successful LAAO with the Amplatzer Amulet device with a propensity score-matched control cohort of 1,184 incident AF patients treated with DOACs. The mean age was 75 in both groups and about 62% were men.

Propensity score matching was based on the covariates of the CHA2DS2-VASc (congestive heart failure, hypertension, age 75 and older, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) and HASBLED score (hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) for predicting stroke and bleeding.

Participants were followed for two years. The primary outcome was a composite of ischemic stroke, major bleeding (Bleeding Academic Research Consortium, 3 or more), or all-cause mortality.

Patients treated with LAAO had a significantly lower risk of the primary composite outcome compared with those treated with DOACs (hazard ratio, 0.57).

Total events and event rates per 100 patient-years for LAAO versus DOACs were 256 versus 461 and 14.5 versus 25.7, respectively.

The risk of ischemic stroke was comparable between groups (HR,1.11). By contrast, risk of major bleeding (HR, 0.62) and all-cause mortality (HR, 0.53; 95% CI: 0.43 to 0.64) were significantly lower in LAAO-treated patients.

Notably, only 283 (23.9%) AF patients continued DOAC treatment for the full two-year follow-up.

Dr. Nielsen-Kudsk said, "Our research group, in collaboration with other Nordic LAAO and stroke centers, has initiated two randomized clinical trials comparing LAAO to best medical care in AF patients with prior intracerebral bleeding and in AF patients with a prior ischemic stroke." These and two large international trials investigating LAAO versus NOAC among AF patients suitable for long-term anticoagulation are also underway.

"It will take at least two to five years before we have data from these randomized LAAO trials," he noted. "Meanwhile, based on (previous) data, LAAO should be considered in clinical practice for patients who have a high risk of bleeding or who for any other reason are unsuitable for long-term DOAC treatment."

Dr. Mohamad Alkhouli of Mayo Clinic School of Medicine in Rochester, Minnesota, author of a related editorial, commented in an email to Reuters Health, "LAAO is approved based on trials that compared its efficacy to warfarin. However, warfarin has been largely replaced by DOAC in contemporary practice and data directly comparing LAAO to DOAC are very limited."

"This study attempts to bridge some of this knowledge gap," he said. "It provides reassurance that the way LAAO is practiced now (i.e., mostly as an alternative to DOAC in selected patients) is safe. It does, however, highlight the limitations of observational data and the need for prospective randomized evidence before LAAO indications are expanded."

Like Dr. Nielsen-Kudsk, he noted, "The good news is that we have five trials with >9,000 participants underway to address this issue. Till the results of these trials become available, the success of LAAO as a therapy will continue to rely on careful patient selection, and evidence-informed shared-decision."

Dr. Alkhouli and a colleague outline remaining challenges with transcatheter left atrial appendage closure in a recent article in Mayo Clinic Proceedings (https://mayocl.in/3q9jQJu).

The study was supported by the Novo Nordisk Research Foundation and Abbott. Dr. Nielsen-Kudsk served as a proctor and investigator for Abbott and two coauthors have received fees from the company.

SOURCE: https://bit.ly/39tnU0r and https://bit.ly/2XAljww JACC: Cardiovascular Interventions, online January 11, 2021.

By Marilynn Larkin



Posted on 12 January 202119 January 2021