[Oral anticoagulation and platelet inhibition after atrial appendage occlusion]

In Europe left atrial appendage occluders (LAAO) are most frequently used in patients with contraindications for oral anticoagulation (OAC); therefore, the classical therapeutic OAC scheme from the PROTECT-AF trial (vitamin K antagonist plus acetylsalicylic acid) is usually changed to dual anti-platelet therapy (DAPT) after implantation of a Watchman® or Amulet® LAAO (St. Jude Medical/Abbott, Eschborn, Germany). For many years, patients with an LAAO received DAPT for 1-6 months. The current standard comprises DAPT for 3 months, followed by permanent acetylsalicylic acid monotherapy if the transesophageal echocardiogram excludes a thrombus at the site of the LAAO. In patients with high risk of bleeding, anti-platelet therapy can be stopped at 3 months after an individual risk-benefit calculation. There are no randomized studies on the risk of bleeding and stroke/embolism in patients with an LAA occluder under DAPT versus OAC. Experience from the EWOLUTION registry shows that NOACs may be used as an alternative with low bleeding and thrombus risks. In patients with a suboptimal implantation result, thrombus on the LAAO or specific risk factors, variations of the standard scheme have to be applied and if necessary lifelong DAPT or NOAC therapy has to be used. Thrombi on the LAAO occur in approximately 4-6% of patients and are associated with a very low short-term stroke risk.