On Monday (19 June), the Late Breaking Trial session of EHRA EUROPACE - CARDIOSTIM focused on the key areas of electrophysiology: left atrial appendage occlusion, atrial fibrillation ablation, and leadless pacing. In this article, Congress News reviews the topline results from this session.

The two studies that were presented during the left atrial appendage occlusion section both reviewed the incidence of device thrombosis following implantation of a left atrial appendage occlusion device. As reported in yesterday’s edition of Congress News, Professor Laurent Fauchier (Trousseau Regional University Hospital, Tours, France) told Congress News that he and his colleagues “were not able to find an antithrombotic strategy clearly associated with a lower risk of thrombus formation, but a strategy with no antithrombotic at all is, at the moment, probably not a satisfying option”.

In their real-life registry study, Doctor Boris Schmidt (Cardioangiologisches Centrum Bethanien, Frankfurt, Germany) and colleagues found that device thrombosis was observed in 10 patients (of 897) at 35±28 days post implant and four of these patients were receiving antiplatelet therapy, three were receiving dual antiplatelet therapy, two were on oral anticoagulation, and one was on neither oral anticoagulation nor antiplatelet therapy. Furthermore, of this group with device thrombosis, one patient experienced a stroke while being on antiplatelet therapy 71 days after the procedure. However, presenting the data at the Late Breaking Trial session, Dr. Schmidt said that—overall—the early post-procedure stroke rate and the echo-detected thrombus rate were lower than what has been reported previously across a range of devices and that this finding was “in spite” of the fact that the majority of patients implanted with a left atrial appendage occlusion device were discharged without being on oral anticoagulation.

Speaking to Congress News, he commented that his and his colleagues’ study will “allow us to better understand the currently applied drug regimens used globally and their merits and demerits in terms of stroke and bleeding”. However, he added: “To search for the optimal therapy, we will need prospective randomised studies.”

In the atrial fibrillation section, which immediately followed the left atrial appendage occlusion section, Doctor Milena Leo (Oxford University Hospitals NHS Foundation Trust, Oxford, UK) presented the results of the PiLOT-AF study. She told Congress News (see the report in yesterday’s edition) that the study suggested that “a high efficacy and safety profile of short radio-frequency applications at high powers for atrial fibrillation ablation on the left atrial posterior wall. Larger randomised controlled trials with follow-up data are needed to confirm the results of our study”.

In his presentation, Doctor Atul Verma (Southlake Regional Health Centre, Newmarket, Canada) outlined observations from the real-world ABLATOR registry. He reported that the study evaluated the safety and efficacy of a fibre optic contact force catheter in patients with persistent atrial fibrillation, noting that previous studies of the catheter have looked at a “largely paroxysmal atrial fibrillation” patient population. According to Dr. Verma, the catheter was associated with an acute success rate of 95% (with 22±22 minutes between final ablation and confirmation of pulmonary vein isolation). At one year, the success rate was 57% with no significant difference between first-time and repeat procedures, antiarrhythmics were continued in 23% of patients, and repeat procedures have occurred in 13% of patients during follow-up.

He told Congress News: “The study presented at EHRA EUROPACE – CARDIOSTIM represents an exclusively persistent atrial fibrillation population in a large real-world registry, including multiple centres from across the world. In this way, it is a practical look at the value of the technology in a persistent atrial fibrillation population.”

Doctor Paul Richard Roberts (Cardiology, Wessex Cardiac Centre, Southampton, UK), during the leadless pacing section of the session, gave a presentation on the real-world experience with a transcatheter pacemaker. He told Congress News that, prior to the study, data for the device have been limited to the “controlled investigational environment”.

“While the results are reassuring, questions remain about the reproducibility of the positive findings and the performance outside the investigational setting,” Dr. Roberts commented. The study indicated, he reported, that the transcatheter pacemaker “in the hands of new operators” can be “implanted successfully and with very few complications”. He noted: “An interim analysis of the registry showed that 149 implanters from around the world, of whom 87% had no prior experience, were able to implant the device with high success (99.6%). Very few patients (1.51%) experienced a major complication at 30 days post implant.”

Looking at a different leadless pacemaker device, Doctor Reinoud Knops (Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Medical Center, University of Amsterdam, Amsterdam, The Netherlands) described battery failures with the device. He noted that last year, an alert regarding battery malfunction was issued for the device.

“As with standard pacemakers, leadless pacemakers are subject to critical battery failures. Chronic retrievability looks promising with >90% of leadless pacemakers successfully retrieved percutaneously,” Dr. Knops concluded.

The Late Breaking Trial session was chaired by Professor Gerhard Hindricks (University Leipzig–Heart Center, Leipzig, Germany), who is the current President of the European Heart Rhythm Association (EHRA); Professor John Camm (St Georges University of London, London, UK), EHRA President-Elect, and Doctor Arnaud Lazarus (InParys Clinical Research Associates, St Cloud, France).

As well as the Late Breaking Trial session, there was the opportunity to review Late Breaking posters in the poster area throughout Sunday (18 June). There were posters on the detection of long-term complications after implantation cardioverter defibrillator (ICD) surgery, advanced imaging supported left ventricular lead placement in cardiac resynchronisation therapy, and new insights into the clinical polymorphism of SCNA-related arrhythmic syndromes revealed by deep phenotyping.

Late Breaking Trial Session: Left atrial appendage occlusion