The Assessment of the Watchman Device in Patients Unsuitable for Oral Anticoagulation (ASAP-TOO) trial

David R. Holmes, Vivek Y. Reddy, Maurice Buchbinder, Kenneth Stein, Myriah Elletson, Martin W. Bergmann, Boris Schmidt, Jacqueline Saw

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Background Oral anticoagulants (OACs) reduce stroke risks with nonvalvular atrial fibrillation (AF); however, they are underused because of absolute or relative contraindications due to real or perceived risk of bleeding. Although left atrial appendage closure is increasingly performed in OAC-ineligible patients, this has not been studied in a randomized controlled trial. Study objectives The ASAP-TOO study is designed to establish the safety and effectiveness of the Watchman left atrial appendage closure device in patients with nonvalvular AF who are deemed ineligible for OAC. The primary effectiveness end point is the time to first occurrence of ischemic stroke or systemic embolism. The primary safety end point includes all-cause death, ischemic stroke, systemic embolism, or device- or procedural-related event requiring open cardiac surgery or major endovascular intervention. Study design This is a multinational, multicenter prospective randomized trial. Patients meeting the inclusion criteria with CHA2DS2-VASc score ≥ 2 and who are deemed by 2 study physicians to be unsuitable for OAC will be randomized in a 2:1 allocation ratio to Watchman versus control. Control patients will be prescribed single antiplatelet therapy or no therapy at the discretion of the study physician. Up to 888 randomized subjects will be enrolled from up to 100 global investigational sites. Both device group and control patients will have follow-up visits at 3, 6, and 12 months and then every 6 months through 60 months. Summary This trial will assess the safety and efficacy of Watchman in this challenging population of high–stroke risk AF patients.

Original languageEnglish (US)
Pages (from-to)68-74
Number of pages7
JournalAmerican heart journal
StatePublished - Jul 1 2017

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


Dive into the research topics of 'The Assessment of the Watchman Device in Patients Unsuitable for Oral Anticoagulation (ASAP-TOO) trial'. Together they form a unique fingerprint.

Cite this