LAA Closure Trials Illustrate Evolution of Devices, Trial Design


Devices for percutaneous closure of the left atrial appendage (LAA) have demonstrated encouraging results over recent years in terms of performance but appear to vary in terms of safety, according to presentations on Sunday at TCT 2015. Experts offered an overview of the rapidly expanding LAA closure field, noting many upcoming trials that could sway clinical practice. 

Amplatzer Amulet    

Reda Ibrahim, MDReda Ibrahim, MD, of the University of Montreal in Canada, discussed the Amplatzer cardiac plug (St. Jude Medical). Future research efforts are now aimed at the next generation of this device, known as Amplatzer Amulet. Amulet will be reviewed in an ongoing prospective post-market observational study, which is expected to enroll 1,000 patients in 50 centers across the world where the device is approved. In contrast to its predecessor, the Amulet device is expected to be easier to use, can expand its size range to treat larger appendages and incorporates modifications to improve device performance, Ibrahim reported.   

“We need more randomized trials on these [developing] devices before wider acceptance occurs, particularly in comparison with Watchman and the use of [novel oral anticoagulants] in warfarin-intolerant patients,” he said.     

Watchman device 

David R. HolmesDavid R. Holmes Jr., MD, of the Mayo Clinic in Rochester, Minn., presented findings on the Watchman device (Boston Scientific). The device, FDA-approved in March of this year, is indicated for the reduction of thromboembolism in patients with non-valvular AF who are at increased risk for stroke and systemic embolism. Patients must be eligible for treatment with warfarin but have an appropriate rationale to seeking an alternative treatment.  

There are 39 centers implanting the Watchman device to date, Holmes reported. Available data include nearly 3,300 patients with less than 7 years of follow-up across the PROTECT AF, CAP and PREVAIL trials.

“Data indicate that the Watchman device produced a 40% reduction in mortality when compared with all other available devices,” he commented. “Hemorrhagic stroke is dramatically less, in addition to a dramatically [reduced] risk for unexplained death among study participants.”

Many patients treated with the Watchman device can indeed discontinue warfarin without experiencing any fallout in terms of incidence of hemorrhagic stroke, Holmes said. A post-approval study is slated to follow 1,000 Watchman-implanted patients for 2 years. In addition, a novel surveillance approach is expected to provide data on how the Watchman device is performing across hospitals and institutions.

“Complication rates are becoming smaller and smaller, but they will never be zero,” said Holmes. 

AMAZE trial 

Randall J. Lee, MD, PhD, of the University of California, San Francisco, discussed the ongoing multicenter, prospective, randomized AMAZE trial, which is evaluating LAA closure with the Lariat device (SentreHEART) as an adjunctive treatment to pulmonary vein isolation (PVI) ablation in persistent or longstanding persistent AF. The study will be carried out in two randomized stages, with a primary endpoint of freedom from AF episodes greater than 30 seconds at 1-year post-PVI.

“As an electrophysiologist, I see patients with AF all the time, and the thing that is very difficult is that patients with persistent AF do not do well with medications,” Lee commented.

Disclosures:

  • Holmes reports financial interest in technology related to the Watchman device from Boston Scientific Corporation.  
  • Ibrahim reports receiving grant/research support and consultant/honoraria fees from AstraZeneca, Boston Scientific Corporation, Gore, Medtronic and St. Jude Medical. 
  • Lee reports being a consultant and equity holder for SentreHEART.  

 

 

Comments