Left atrial appendage occlusion for patients with valvular diseases without atrial fibrillation (the OPINION Study): study protocol for a multicentre, randomised controlled trial.

introductionAtrial fibrillation (AF) is a significant cause of perioperative stroke in aortic and mitral valve surgeries. Although several large studies have evaluated surgical left atrial appendage occlusion (SLAAO) during cardiac surgeries, their retrospective nature and an uncontrolled broad spectrum of conditions leave them subject to potential residual confounding. This trial aims to test the hypothesis that opportunistic SLAAO can prevent long-term stroke after cardiac surgery in patients receiving mitral or aortic valve surgeries without a history of AF and with a CHA2DS2-VASc score of 2 or higher. METHODS AND

designThis study is a single-blinded, multicentre, randomised controlled trial. A total of 2118 patients planning to undergo aortic or mitral surgery without AF will be recruited and equally randomised into intervention or control arms at a 1:1 ratio. In the intervention arm, suture excision of the left atrial appendage (LAA) will be performed during the operation in addition to the original surgery plan. In the control arm, the operation will be performed according to the surgery plan without any intervention on the LAA. The primary outcome is a composite of newly occurred ischaemic stroke or transient ischaemic attack and cardiovascular mortality during a 1-year follow-up. Secondary outcomes include postoperative AF, cardiovascular mortality, newly occurred ischaemic stroke, newly occurred transient ischaemic attack, newly occurred haemorrhagic stroke, bleeding events, and AF-associated health utilisation. ETHICS AND DISSEMINATION: The Ethics Committee in Fuwai Hospital approved this study. Patients will give informed consent to the study. An information leaflet will be provided to participating patients to introduce the SLAAO procedure. Patients and the public will not get involved in developing the research hypothesis, study design or any other part of this protocol. We plan to publish several papers in peer-reviewed journals about the current research and these will include a description of the study's development and the main findings of the study. TRIAL REGISTRATION NUMBER: ChiCTR2100042238.