The OPTION trial is an international prospective study involving 1,600 patients who underwent catheter ablation for atrial fibrillation (AF). Patients were randomised to receive either anticoagulant therapy (OAC) or left atrial appendage closure (LAAC) device.  At 36 month follow-up, the LAAC group (797 patients) demonstrated superiority over the OAC group (803 patients) on the safety endpoint (consisting of non-procedure-related major bleeding or clinically relevant nonmajor bleeding) and non-inferiority on the efficacy composite endpoint of death from all causes, stroke and systemic embolism.

The superiority demonstrated at the safety endpoint was driven by non-major bleeding (e.g. epistaxis, contusions, and oral bleeding), possibly influenced by bias resulting from the open-label design (patients more likely to report events). In terms of secondary endpoints, ISTH major bleeding, including procedure related bleeding, through 36 months occurred in 30 patients in the device group and in 38 patients in the anticoagulation group. This difference met the criterion for noninferiority (P<0.001) but not superiority (P = 0.28).

In relation to the efficacy endpoint, it is crucial to acknowledge that the use of death from any cause and the low actual event rates (5.3% vs. 5.8%) in comparison to the expected ones (10% vs. 15%) facilitated the achievement of non-inferiority.

In conclusion, although the OPTION trial provides positive data on the usefulness of LAAC as an alternative to OAC, the study has some limitations. Further randomised controlled trials (RCTs) are required to define the best tailored therapy to be chosen for each individual patient.