Device-related thrombus after left atrial appendage occlusion in patients with atrial fibrillation: a prospective follow-up

Aim . To study the incidence, predictors, and clinical outcome of device-related thrombus (DRT) after left atrial appendage occlusion (LAAO) in patients with atrial fibrillation (AF). Methods. A prospective observational study included 120 patients with non-valvular AF who underwent LAAO with Watchman (n=92) and Amplatzer Amulet (n=28). The presence of device-related thrombus (DRT) was assessed at visits 45 days, 6 months, 1 year, 2 years, 3 years after implantation by transesophageal echocardiography. Results . A total of 11 (9.2%) patients had DRT during the follow-up period. The greatest number of thrombosis was observed after 45 days (n=4) and after 6 months (n=4). There was no significant difference in the incidence of DRT between device types. Independent predictors of thrombosis were: history of myocardial infarction (hazard ratio (HR) 12.88 [95% confidence interval (CI) 3.21-51.62]; p<0.001), chronic heart failure (HR 8.83 [95% CI 1.91-40.77]; p=0.005), residual leak size >5 mm in the early postoperative period (HR 6.13 [95% CI 2.53-14.86]; p<0.001) and the degree of spontaneous echo contrast during the initial examination (HR 9.09 [95% CI 1.36-60.58], p=0.023). There were no cases of thromboembolic complications associated with DRT. One patient developed a non-fatal stroke at 35 weeks of follow-up, while DRT was detected at the visit at the end of the 3rd year of follow-up. Conclusion. DRT after LAAO was observed in the early and long-term follow-up periods. This event was associated with the baseline patients’ characteristics and post-procedural aspects with no dependence on type of antithrombotic therapy.