ORLANDO – Intracardiac echocardiography (ICE) can be safely substituted for transesophageal echocardiography (TEE) as a less invasive option in the placement of an investigational percutaneous device for left atrial appendage (LAA) occlusion, according to data presented at the annual International AF Symposium.
The relative safety and efficacy of ICE and TEE for placement of the device, called the Amplatzer Amulet, was evaluated as a subanalysis of a large, nonrandomized, observational study, according to Boris Schmidt, MD, of Cardiovascular Center Bethanien, Frankfurt, Germany.
The Amplatzer Amulet device, which is designed to prevent LAA-associated thromboembolism in patients with nonvalvular atrial fibrillation (AF), has been available in Europe for several years. It functions much like Boston Scientific’s Watchman implant. A registration trial in the United States was initiated in 2016.
In the study that provided the basis for this analysis, 1,088 AF patients were implanted. The average age was 75 years, and the population was relatively high risk for both stroke and bleeding. The CHA2DS2-VASc score was at least 4 in 65% of patients, with an average score of 4.2. Prior stroke (28%) and transient ischemic attack (11%) had occurred in more than one-third. Reflecting the fact that 72% had a history of a major bleed, the average HAS-BLED score was 3.3. More than 80% were hypertensive.
The decision to place the device with TEE, which Dr. Schmidt characterized as the standard, or ICE was left up to the discretion of the implanter. Ultimately, 958 (88.4%) of the devices were placed with TEE and 126 (11.6%) with ICE.
There were no significant differences in implant success or safety when the two methods for guiding implantation were compared. Specifically, success was achieved in 99.2% of the ICE group with 90.5% of cases requiring only one device. In the TEE group, the device was successfully implanted in 98.4%, and 94.4% needed only one device. The first device to be selected was ultimately implanted in 96.5% of the ICE group and 94.4% of the TEE group. The LAA closure rate, defined as gap of less than 3 mm, was 100% at implant and 3 months after transplant in the ICE group, when evaluated by an independent core laboratory. The closure rates in the TEE group at the time of implant and 3 months later were 99.8% and 98.6%, respectively. No difference between imaging methods approached statistical significance.
Adverse events, which were also adjudicated by independent investigators, occurred at low rates and also did not differ by imaging strategy. In the ICE and TEE groups, respectively, these included vascular complications in 0.9% and 1.6%, pericardial effusion in 1.0% and 0.8%, stroke in 0.3% and 0%, and embolization in 0.1% and 0%. With a median follow-up of 6.6 months, there have been four deaths. Two were considered to be device related by the adjudicators. One involved a perforation and another a cardiac arrest. Both were observed in the TEE group.
The Amplatzer Amulet device consists of a lobe that is designed to fit inside the LAA neck and a disk that provides a complete seal at the orifice. It was first introduced in Europe in 2008 but has undergone several modifications. In the United States, the Watchman, which opens like an umbrella in order to block passage of thromboemboli when deployed in the LAA, received FDA approval in 2015. Other LAA closure strategies are in development. There are no large randomized trials in which LAA closure devices have been compared.
Dr. Schmidt has financial relationships with Boston Scientific and St. Jude Medical.