What Lies Beneath Left Atrial Appendage Occlusion

In this issue of Circulation: Cardiovascular Interventions , a Polish institution carefully analyzed ≈100 patients undergoing left atrial appendage (LAA) occlusion with serial transesophageal echocardiographies or computer tomographies at 1.5 (early), 3 to 6 (late), and 12 (very late) months with particular focus on device-related thrombus (DRT) and peridevice leak (PDL).1 The patients were treated without oral anticoagulation but with dual antiplatelet therapy for 1 to 6 months at the discretion of the operators. DRT was diagnosed in 7%. The distribution of DRTs to the 3 control intervals was quite even: 2% early, 2% late, and 3% very late. Of these 7 DRTs, 4 resolved by adding low–molecular weight heparin to the antiplatelet treatment and 3 persisted in spite of treatment adjustment. One of the patients with DRT had a stroke which was fatal. None of the patients without DRT had an embolic event during the 1-year follow-up.See Article by Pracon et al The 2 most common devices, the Amplatzer and the Watchman occluders, were used for about half of the cases each. Deep implantation was found to be the most significant predictor for DRT. The distance of the most proximal part of the device to the tip of the pulmonary ridge, the structure separating the LAA from the left upper pulmonary vein, was used for the definition of deep implantation. For the Amplatzer device, a 2-component structure consisting of an anchoring lobe and a covering disc according to the pacifier principle2 any position not covering the peak …