Novel Devices Provide Options for LAA Therapy

MIAMI BEACH, FLA.—As the Watchman left atrial appendage closure device (Atritech) moves closer to FDA approval for the treatment of atrial fibrillation (AF), encouraging preliminary data are also emerging for a similar device.

Jai-Wun Park, MD, of Asklepios Hospital in Hamburg, Germany, presented data at TCT 2012 from the Amplatzer Cardiac Plug (AGA Medical) European Multicenter Observational Study, which included 204 patients with non-valvular AF.

Park highlighted encouraging implant and occlusion success rates with the device (see Figure).

The higher-risk patient population included patients who were intolerant to anticoagulation with a CHADS2 score of 2.6. The patient population had a prior history of stroke of 37.9%, according to Park. The rate of safety events was 5.4%. Also, there were only 2 strokes over 101 patient years for a rate of 1.98% compared with the CHADS2 prediction of 5.6%, representing a 65% reduction in stroke risk from the estimated rate.

“This compares favorably with other devices and previous [Amplatzer Cardiac Plug] publications,” Park said.

He added that further training on implant technique and experience would mitigate the risk of safety events.

PREVAIL

Saibal Kar, MD, of the Heart Institute at Cedars-Sinai Medical Center in Los Angeles, Calif., provided an update from the PREVAIL trial, which had similar protocols as PROTECT AF, the first randomized trial demonstrating that LAA closure using Watchman was noninferior to long-term warfarin.

Kar described PREVAIL as a landmark confirmatory study evaluating the role of the Watchman device in patients with AF who are at significant risk for stroke. High risk patients were defined as those with a CHADS2 score ≥ 2. Patients were randomized from 50 US sites in a 2:1 ratio of Watchman to warfarin. Twenty percent of the centers and 25% of the operators had no prior experience with the device. “We wanted to show that you could transfer this to new people,” said Kar.

Kar said that the 400th patient was randomized in June 2012, and that the last 6-month follow-up visit will be in December 2012.

FDA approval

David R. Holmes Jr, MD, of the Mayo Clinic in Rochester, Minn., discussed long-term results, risks and benefits of the Watchman device in the context of the PROTECT AF trial, the CAP and ASAP registries and the ongoing PREVAIL trial. According to Holmes, the PROTECT AF trial has shown a 23% reduction in relative risk for all-cause stroke in the Watchman group vs. controls. There is also a 30% lower RR for all-cause mortality. “When we break it down to patient subgroups, looking at long-term, the device is superior,” said Holmes.

Holmes added that the Aspirin and Plavix Registry results indicate that the observed rate of ischemic stroke represents a 77% reduction with Watchman from the expected event rate.

“From these findings we can gather that this device prevents stroke, improves survival and does not necessarily have to be used with warfarin,” he said. “In terms of long-term risk-benefit ratio, Watchman is a very real and valuable therapy for these patients when used to prevent stroke or thromboembolism.”

Kar said that long-term data from the PROTECT AF trial, the Continuous Access registry and the PREVAIL trial will be used to seek FDA approval. Material will be submitted to the FDA in February 2013 with an anticipated approval at the end of 2013.