Why is this study important?

This analysis of the National Cardiovascular Data Registry (NCDR) Left Atrial Appendage Occlusion (LAAO) Registry was the first study to show that peri-device leak is associated with increased stroke risk. 

Should I change my practice because of these findings?

Because peri-device leak is associated with increased stroke risk, LAAO operators should assess devices carefully for leak and strive to leave no leak.  

What question was this study supposed to answer? 

The study examined rates of a primary endpoint composite of stroke, transient ischemic attack, and systemic embolism among LAAO patients stratified by no leak, small leak (<5 mm), and large leak (>5 mm).   

What did the study show?

Among 51,333 patients undergoing LAAO with the Watchman 2.5 device (Boston Scientific, Marlborough, MA) from 2016 through 2019, 37,696 (73.4%) had no leak, 13,258 (25.8%) had small leaks (<5 mm), and 379 (0.7%) had large leaks (>5 mm).  The presence of a small leak was associated with a slightly higher rate of the primary endpoint (adjusted HR 1.152, 95% confidence interval [CI] 1.025-1.294), major bleeding (HR 1.11, 95% CI 1.029-1.120), and any major adverse events (HR 1.102, 95% CI 1.048-1.160).  Large leaks were not statistically associated with adverse events, although more patients with large leaks continued anticoagulation. 

How good was the approach/methodology? 

The NCDR LAAO Registry is the largest LAAO dataset in the world, including every commercial LAAO procedure performed in the US.  However, the study was subject to the usual cadre of biases inherent when performing a retrospective analysis of a large data registry, particularly information bias.   
 

All editors: Andrew M. Goldsweig, MD, MSC, RPVI, FSCAI 

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