American College of Cardiology
American College of Cardiology
April 07, 2020
3 min read

Registry data show lower event rates vs. trial data for LAA closure device

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James V. Freeman

Patients with atrial fibrillation who underwent left atrial appendage occlusion with an FDA-approved device had lower rates of major in-hospital adverse events compared with previous trials assessing the device, according to data presented at the virtual American College of Cardiology Scientific Session.

These results for the device (Watchman, Boston Scientific) were also published in the Journal of the American College of Cardiology.

Registry data

James V. Freeman, MD, MPH, MS, cardiac electrophysiologist, associate professor of medicine and director of the Yale Atrial Fibrillation Program at Yale University School of Medicine, and colleagues analyzed data from 38,158 left atrial appendage occlusion (LAAO) procedures (mean age, 76 years; 60% men; mean CHA2DS2-VASC score, 4.6; mean HAS-BLED score, 3) performed by 1,318 physicians from 495 hospitals from 2016 to 2018.

“The take-home here is that these patients were at moderate to high risk of stroke, about 70% had prior clinically relevant bleeding, and the vast majority had some relative contraindication to anticoagulation,” Freeman said during the presentation.

Researchers obtained data from the National Cardiovascular Data Registry’s Left Atrial Appendage Occlusion Registry.

“The Watchman device was approved by FDA in March of 2015, and the Left Atrial Appendage Occlusion Registry was developed through a collaboration between the American College of Cardiology, the Society for Cardiovascular Angiography and Interventions, FDA, CMS and Boston Scientific,” Freeman said during the presentation.

The registry also included a novel process to adjudicate adverse clinical events during follow-up including hemorrhagic stroke, ischemic stroke, transient ischemic attack, undetermined stroke, systemic embolism, intracranial hemorrhage, major vascular complication and major bleeding. Follow-up data were collected at 45 days, 6 months, 1 year and 2 years.

Hospitals performed a median of 30 procedures per year, with most centers performing fewer than 40 procedures annually. Physicians performed a median of 12 LAAO procedures annually, with most physicians performing fewer than 20 procedures per year.

Seven percent of cases from the registry were canceled or aborted. Of the procedures with deployed devices, 98.1% were implanted with less than a 5 mm leak.

Among the cohort, 2.16% had major in-hospital adverse events, the most common of which were major bleeding (1.25%) and pericardial effusion requiring intervention (1.39%), whereas death (0.19%) and stroke (0.17%) were rare.

“In terms of major in-hospital adverse events, overall, the data were quite reassuring,” Freeman said during the presentation. “Comparing these adverse event rates with prior studies, we see the major in-hospital adverse event rate that we reported of 2.16% is lower than those reported in the pivotal trials through 7 days. Both PROTECT-AF and PREVAIL reported higher rates of pericardial effusion, major bleeding, procedure-related stroke and device embolization compared to what we’re reporting, albeit over a slightly longer time horizon.”


Future research

N.A. Mark Estes III
Dhanunjaya Lakkireddy

During the discussion, panelist N.A. Mark Estes III, MD, cardiologist at the UPMC Heart and Vascular Institute at the University of Pittsburgh School of Medicine, said, “I think one of the key things is subgroup analysis, number of cases done, operator-specific learning curves that you can perform now or you think should be performed that might change the way in which we move forward with the registry in the future.”

In a related editorial in JACC, Dhanunjaya Lakkireddy, MD, medical director of the Kansas City Heart Rhythm Institute at HCA Midwest Health in Overland Park, Kansas, and Mohit K. Turagam, MD, cardiac electrophysiology fellow at Icahn School of Medicine at Mount Sinai, wrote, “Although registry data is not a substitute for randomized controlled trials, this well-designed prospective database with collaboration between various professional societies, the FDA, CMS and industry will serve as a useful vehicle in refining patient selection and tracking the safety and efficacy of LAAO devices for the next several decades.” – by Darlene Dobkowski


Freeman JV, et al. Featured Clinical Research II: Interventional. Presented at: American College of Cardiology Scientific Session; March 28-30, 2020 (virtual meeting).

Freeman JV, et al. J Am Coll Cardiol. 2020;doi:10.1016/j.jacc.2019.12.040.

Lakkireddy DR, et al. J Am Coll Cardiol. 2020;doi:10.1016/j.jacc.2020.01.007.

Disclosures: The study was funded by the ACC National Cardiovascular Data Registry and the NHLBI. Freeman reports he received salary support from the ACC National Cardiovascular Data Registry and the NHLBI and consultant/advisory board fees from Biosense Webster, Boston Scientific, Janssen Pharmaceuticals and Medtronic. The authors of the editorial report no relevant financial disclosures. Estes reports he received consultant fees/honoraria from Boston Scientific, Medtronic and St. Jude Medical. Please see the study for all other authors’ relevant financial disclosures.