Left atrial appendage closure with WATCHMAN in Asian patients: 2 year outcomes from the WASP registry

Karen P. Phillips, Teguh Santoso, Prashanthan Sanders, Jeffrey Alison, Jason Leung Kwai Chan, Hui Nam Pak, Mann Chandavimol, Kenneth M. Stein, Nicole Gordon, Omar Bin Razali

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


Background: Left atrial appendage closure is a non-pharmacological alternative for stroke prevention in high-risk non-valvular atrial fibrillation patients, but has not been widely studied in Asian patients. The prospective WASP registry assessed real-world outcomes for patients undergoing WATCHMAN implant in the Asia-Pacific region. Methods: Data were collected from consecutive patients across 9 centres. Major endpoints included procedural success, safety and long-term outcomes including occurrence of bleeding, stroke/transient ischaemic attack/systemic embolism and all-cause mortality. Results: Subjects (n = 201) had a mean age of 70.8 ± 9.4 years, high stroke risk (CHA 2 DS 2 -VASc: 3.9 ± 1.7), elevated bleeding risk (HAS-BLED: 2.1 ± 1.2) with 53% patients from Asian countries. Successful implantation occurred in 98.5% of patients; 7-day device/procedure-related SAE rate was 3.0%. After 2 years of follow-up, the rates of ischaemic stroke/TIA/SE and major bleeding were 1.9 and 2.2 per 100-PY, respectively, representing relative reductions of 77% and 49% versus expected rates per risk scores. The relative risk reductions versus expected rates were more pronounced in Asians vs. Non-Asians (89% vs 62%; 77% vs 14%). Other significant findings included larger mean LAA ostium diameter for Asians vs. Non-Asians (23.4 ± 4.1 mm vs. 21.2 ± 3.2 mm, p < 0.001) and hence requirement for larger median device size (27 mm for Asians, 24 mm for non-Asians [p < 0.0001]). Conclusion: Real-world experience of left atrial appendage closure with WATCHMAN has demonstrated low peri-procedural risk, and long-term efficacy for stroke and bleeding prevention in a primarily Asian cohort.

Original languageEnglish
Article number100358
JournalIJC Heart and Vasculature
Publication statusPublished - 1 Jun 2019


  • Anticoagulant therapy
  • Atrial fibrillation
  • Ischaemic stroke
  • LAA device closure
  • Left atrial appendage

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