Heart failure and late leaks should be considered as late complications of left atrial appendage occlusion

With great interest, we read the expert consensus statement on catheter-based left atrial appendage occlusion (LAAO) by Glikson et al.1 The authors have to be congratulated for their highly critical analysis of the studies and registries on LAAO reported so far (Chapter 6). We would like to add the following considerations: The recommendations of Table 8 state that post-procedural imaging should be performed at 6–24 weeks post-implantation to assess for device-related thrombus (DRT) and may be repeated after 12 months post-LAAO for assessment of DRT.1 The rate of thrombus formation on the device during long-term follow-up, however, is largely unknown. The development of new peri-device leaks which have been described after an initially completely closed LAA during follow-up is not addressed in the recommendations.2 Since no systematic investigations regarding leaks >12 months post-interventionally have been performed, the incidence and consequence of such late peri-device leaks still remains to be determined. The anatomy of the LAA is described in great detail by the authors; however, the functional and endocrine properties of the LAA have been completely ignored. Since the LAA is 2.6 times as compliant as the left atrial body this structure contributes significantly to left atrial reservoir function and is essential for the adaption to pressure and volume overload.3 In addition, the LAA is an important structure for the release of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), and a significant decrease of ANP- and BNP-serum levels after interventional LAA closure has been described. Both of these mechanisms may result in the development of heart failure after LAAO.4 Following interventional LAA closure rehospitalizations for heart failure have recently been reported in 17% of the patients.5 Complications regarding local or systemic infection after LAAO have not been discussed. Interventional LAA closure interacts unfavourably with left atrial compliance and reservoir function as well as ANP and BNP secretion. Unfortunately, the development and aggravation of heart failure was not consistently assessed in any trial on LAAO and is not planned to be registered as an endpoint or adverse event in ongoing studies.1 Conflict of interest: none declared.