Clinical Impact of Peridevice Leak Following Left Atrial Appendage Closure

Left atrial appendage closure (LAAO) has consolidated as a valid strategy for thromboembolic event prevention in patients with non-valvular atrial fibrillation (NVAF), especially in patients with oral anticoagulation contraindication. 

However, the presence of peridevice leak (PDL) following LAAO has raised questions about its long term clinical impact. 

The OCEAN-LAAC, a Japanese multicenter study, prospectively looked at PDL repercussion by transesophageal EKG immediately after procedure and during clinical followup. This analysis focused mainly on leaks deemed “acceptable” (≤3 mm).  

The primary outcome was incidence of thromboembolic events – transient ischemic attack (TIA), ischemic stroke or systemic embolization – within two years after procedure. Secondary end point was all cause mortality at 2 years. 

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Data from 1397 patients were analyzed. 6% presented PDL, mean patient age was 77.5, and they were mostly men; mean CHA₂DS₂-VASc score was 4 and HAS-BLED was 3. PDL was observed mostly in patients with elevated baseline heart rate, larger LAA ostial diameter and in most Watchman 2.5 devices, vs FLX.

Ischemic event incidence was significantly higher in patients with any PDL (Gray’s Test, p=0.0036), including those ≤3 mm (sHR: 3.53; CI95%: 1.37–9.04; p=0.016). Altogether, data show the presence of PDL is associated with nearly four times more ischemic events (sHR: 4.25; CI95%: 1.91–9.44; p<0.001).

However, this increase of thromboembolic events does not translate into higher global mortality, probably because of the non-fatal nature of many TIA and ischemic strokes, as well as timely intervention. 

Conclusion

These results suggest that leaks detected after procedure, including those deemed acceptable in size, might have relevant clinical impact on patient prognosis. 

Original Title: Impact of Peridevice Leak on Clinical Outcomes After Left Atrial Appendage Closure: The OCEAN-LAAC Registry.

Reference: Saito T, Tsuruta H, Kajino A, Iwata J, Sakata S, Ryuzaki T, Sago M, Tanaka S, Chatani R, Hachinohe D, Naganuma T, Ohno Y, Tani T, Okamatsu H, Mizutani K, Watanabe Y, Izumo M, Saji M, Mizuno S, Ueno H, Kubo S, Shirai S, Nakashima M, Asami M, Yamamoto M, Ieda M, Hayashida K; OCEAN‐LAAC investigators. Impact of Peridevice Leak on Clinical Outcomes After Left Atrial Appendage Closure: The OCEAN-LAAC Registry. J Am Heart Assoc. 2025 Aug 18:e044422. doi: 10.1161/JAHA.125.044422. Epub ahead of print. PMID: 40820980.