A win for left atrial appendage occlusion devices

By Dr Aswin Babu

PRAGUE-17 was a multi-centre, prospective, randomised, non-inferiority trial assessing the efficacy of left atrial appendage closure (LAAC) when compared to direct oral anticoagulants (DOACs) in reducing net bleeding and ischemic events in patients with non-valvular atrial fibrillation (AF) 1,2. The initial results were reported after a median duration of 19.9 months which suggested that LAAC devices were non-inferior to DOACs2. At that time, there were no differences in bleeding outcomes between both groups [2]. The contemporary PRAGUE-17 trial publishes the 4-year outcomes of these patients1.

Patients with one of the following of: CHA2DS2-VASc score > 3, HASBLED score > 2, history of clinically significant bleeding or history of a cardioembolic event whilst on anticoagulation were included. 402 patients were randomised to receive either a LAAC device (n=201) or DOAC (n=201). The mean age of the population was 73 years with a mean CHA2DS2-VASc score of 4.7 + 1.5 and a mean HAS-BLED score of 3 + 0.9.

The primary composite endpoint included both bleeding and ischaemic outcomes. This consisted of cardiovascular death, stroke or transient ischemic attack, systemic embolism, clinically significant bleeding, or significant procedure/device-related complication [1]. Secondary endpoints included stroke or TIA and non-procedural bleeding requiring hospitalisation or intervention.

After a median follow-up of 3.5 years, the primary composite endpoint occurred in 49 patients in LAAC group versus 60 patients in the DOAC group (HR 0.81, 95% CI 0.56-1.18, p = 0.27) which met the criteria for non-inferiority [1]. The rates of stroke or TIA were similar between the group with 16 patients affected in the LAAC group versus 15 patients in the DOAC group (HR 1.14, 95% CI 0.56-2.30, p = 0.72). However, major non-procedural bleeding was significantly lower in the LAAC arm (n=23) when rivalled to the DOAC arm (n=40) (HR 0.55, CI 0.31-0.97, p =0.039). Notably, 9 procedural complications occurred in the LAAC group including 2 deaths. Due to the COVID-19 pandemic, a large proportion of follow-up transoesophageal echocardiograms were not performed and thus the amount of device related thrombosis or peri-device leaks remain unknown.

In the context of a broad primary composite endpoint which included contrasting clinical outcomes of both bleeding and ischaemia, LAAC device was non-inferior to a DOAC in preventing overall ischemic and bleeding events in high-risk patients with non-valvular AF. Importantly, the trial was not sufficiently powered to assess the individual components of the primary composite endpoint and thus the results of these analyses will need to be considered cautiously. Further, questions remain regarding appropriate patient selection and how to best utilise the LAAC devices.

View original article on Journal of the American College of Cardiology


  1. Osmancik, P., Herman, D., Neuzil, P., Hala, P., Taborsky, M., Kala, P., Poloczek, M., Stasek, J., Haman, L., Branny, M. and Chovancik, J., 2022. 4-Year Outcomes After Left Atrial Appendage Closure Versus Nonwarfarin Oral Anticoagulation for Atrial Fibrillation. Journal of the American College of Cardiology, 79(1), pp.1-14.
  2. Osmancik, P., Herman, D., Neuzil, P., Hala, P., Taborsky, M., Kala, P., Poloczek, M., Stasek, J., Haman, L., Branny, M. and Chovancik, J., 2020. Left atrial appendage closure versus direct oral anticoagulants in high-risk patients with atrial fibrillation. Journal of the American College of Cardiology, 75(25), pp.3122-3135.