Abbott’s Amplatzer Amulet supplied superior left atrial appendage (LAA) closure over the extinct-guard Watchman (Boston Scientific) system but failed to enormously minimize stroke or bleeding charges in patients with atrial fibrillation, despite theoretical advantages in its make and the flexibility to forgo put up-implant oral anticoagulation.
Oral anticoagulation (OAC) at discharge fell from 96% with the Watchman to 21% with the Amulet, but there was once no significant incompatibility in necessary bleeding between groups at 18 months (11.6% Amulet vs 12.3% Watchman).
The necessary effectiveness endpoint of ischemic stroke or systemic embolism came about in 2.8% of patients in every crew at 18 months (P for noninferiority < .001).
Job-linked complications were better with the Amulet system, driven essentially by pericardial effusions (2.4% vs 1.2%) and system embolization (0.7% vs 0.2%).
Procedural complications were extra general in early conditions, seemingly reflecting a discovering out curve as the AMULET IDE trial was once the essential journey for many US implanters, observed essential investigator Dhanunjaya Lakkireddy, MD, Kansas Metropolis Coronary heart Rhythm Institute, Overland Park, Kansas. “As soon as the operator hits a tag of seven procedures, this rate comes down and ranges off thereafter.”
Results of the essential head-to-head comparability supported the August 14 federal approval of the Amulet for stroke prevention in atrial fibrillation and were reported in a Scorching Line session as of late on the digital European Society of Cardiology Congress 2021.
The system uses twin-seal abilities to bear and end off the LAA and is obtainable in extra than 80 nations, including CE tag approval in Europe in 2013.
Designated discussant Gerhard Hindricks, MD, a co-author of the up to this point 2020 expert consensus dispute on catheter-essentially essentially based mostly left atrial appendage occlusion, congratulated the investigators on executing the greatest LAAO trial to this point and said it’s far a necessity on epic of it “brings true recordsdata to a field the put recordsdata are basically lacking.”
He identified that the watch inclined the older model of the very top-occlusive Watchman system (common within the US in 2015) but enrolled a excessive-be troubled patient inhabitants.
The ability to make exhaust of twin-antiplatelet therapy (DAPT) in these patients with the twin-occlusive Amulet system, he said, “I include map-lustrous and likewise from the patient standpoint, it be a gigantic step forward.”
The Amulet IDE trial randomly assigned 1878 patients with nonvalvular AF to LAAO with the Amulet or Watchman in step with preprocedural imaging at 78 US facilities and 30 facilities outdoors the US. Patients were discharged on aspirin or clopidogrel DAPT or aspirin plus oral anticoagulation if handled with the Amulet and aspirin with or with out warfarin, as mandated for the Watchman.
The inhabitants had a median age of 75 years, a CHA2DS2-VASc rating of 4.5 to 4.7 and HAS-BLED rating of about 3.2. Virtually three fourths had a history of juvenile or necessary bleeding.
The implant was once successful in 98.4% of the 915 Amulet patients and in 96.4% of the 916 Watchman patients.
The necessary endpoint of LAA closure, defined as a residual jet of 5 mm or much less at 45 days, was once executed in 98.9% of patients with the Amplatzer and 96.8% with the Watchman (P for superiority = .0025).
A residual jet of three mm or much less was once extra general with the Amplatzer (89.8% vs 75.1%; P for superiority < .0001).
“The 2% incompatibility in a residual jet of 5 mm was once statistically significant in favor of the twin-occlusive system; on the opposite hand, the clinical relevance of this little incompatibility, on the pause of the day, is unclear whether or no longer that relates to any make of complications one day of apply-up,” said Hindricks, from the Coronary heart Heart of Leipzig, Germany.
The Amulet met noninferiority for the essential composite security endpoint of map-linked complications, all-draw off loss of life, or necessary bleeding via 12 months (14.5% Amulet vs 14.7% Watchman; P = .0002).
Charges for map-linked complications were 4.5% with Amulet and a pair of.5% with Watchman, 3.9% Amulet vs 5.1% Watchman for all-draw off loss of life, and 10.6% Amulet vs 10% Watchman for form 3 or better necessary bleeding.
Panelist Renato D. Lopes, MD, Duke University Clinical Heart, Duke Scientific Research Institute, Durham, North Carolina, agreed the trial represents a significant step for the field and offers clinicians with one other system, but said a 10%–12% bleeding rate is excessive, in particular in elderly patients, in contrast with other unique OAC trials, albeit in general enrolling lower-be troubled patients.
“The formulation I stare it, when we pick a therapy for these patients, we in fact would favor to lower bleeding and abet the efficacy so we can gain the candy notify, but when the bleeding be troubled right here appears to be like to be excessive, how construct we incorporate it in apply?” Lopes said.
Lakkireddy said the watch subselected a inhabitants at excessive be troubled for bleeding and that he wasn’t in fact shocked that bleeding charges were at 10% on epic of prior recordsdata dangle confirmed DAPT doesn’t entirely gain rid of bleeding.
“The truth is, the bleeding is maybe as grand as oral anticoagulation and this is why, I have confidence about, our secondary endpoint was once no longer grand varied from the Amulet DAPT and Watchman Coumadin patients,” he said.
Lakkireddy identified that the Watchman crew stopped oral anticoagulation at 6 weeks after which switched to aspirin plus clopidogrel for up to 6 months sooner than persevering with on single-antiplatelet therapy.An analysis is planned, he said, to “dive deeper into this bleeding narrate to stare if the bleeding complications are all congregated within the essential 45 days within the postprocedure length or were viewed all over apply-up for the 12-month security endpoint.”
Marco Valgimigli, MD, Cardiocentro Ticino Basis, Lugano, Switzerland, asked whether or no longer DAPT would dangle looked varied if the Watchman FLX had been inclined as the comparator.
The Pinnacle FLX trial showed that there would possibly be a excessive rate of closure with the more contemporary iteration but that randomized trials are lacking, and that in conditions with, as an illustration, very clear ostia or very proximal lobes with a vertical takeoff, “a Watchman system is merely no longer a gigantic fit,” Lakkireddy said.
“That is the put, I include, the twin-occlusive mechanism occluders basically shine on epic of that it’s probably you’ll insert the lobe deeper in after which the outer disk beautifully covers the ostium, providing you with the coverage that you just wish with out leaving within the aid of the proximal lobes or other issues and, as a outcomes of which, you will dangle a considerably better closure,” he said.
Now that both devices can be found within the US, Lakkireddy said the usage of imaging, preferably CT, turns into grand extra relevant to make a choice the very top system preoperatively.
Speaking with theheart.org | Medscape Cardiology, Lakkireddy said a worth-effectiveness analysis is planned but that present recordsdata already clearly present LAAO closure is an even bigger financial proposition within the future.
“Within the event you notice on the worth of the exhaust of a DOAC and if you resolve ticket of the worth of treating bleeding and strokes, by 3.5 years the curves immoral over and the left atrial appendage [closure] in fact makes extra sense,” he said. “And atrial fibrillation being a power disease, I include that is a significant earn and something we want to resolve ticket of.”
The trial was once funded by Abbott. Lakkireddy discloses serving on a speaker’s bureau for Boston Scientific, Biosense Webster, and Janssen Prescription pills; and receiving honoraria or talking or consulting prices from Abbott, Stereotaxis, and Atricure.
European Society of Cardiology (ESC) Congress 2021. Presented August 30, 2021.