Author + information
- Stefano Bartoletti, MD,
- Ahmed Masoud, MD, MSc and
- Dhiraj Gupta, MBBS, MD, DM∗ ()
- ↵∗Department of Cardiology, Liverpool Heart and Chest Hospital, Institute of Cardiovascular Medicine and Science, Thomas Drive, Liverpool, Meerseyside L14 3PE, United Kingdom
We read with interest the recent paper by Sedaghat et al. (1) in which they report a high incidence of thrombus between the left upper pulmonary vein and the Amulet device (St. Jude Medical, St. Paul, Minnesota) on transesophageal echocardiogram performed 11.0 ± 8.2 weeks following left atrial appendage (LAA) occlusion. These thrombi were observed in 4 of 24 cases (16.7%) in spite of a strategy of dual antiplatelet therapy for 3 months post-implantation.
The high incidence of thrombus in this Amulet series contrasts with our own experience (2) in a very similar population of patients (mean age: 75 ± 9 years, median CHA2DS2VASc [Congestive Heart Failure, Hypertension, Age ≥75 Years, Diabetes Mellitus, Previous Stroke or Transient Ischemic Attack, Vascular Disease, Age 65 to 74 Years, Sex Category]: 4) undergoing LAA occlusion with the Amulet device. Our patients received 6 weeks of double antiplatelet therapy and no thrombus was visualized in any of 32 patients on follow-up transesophageal echocardiogram at 6 to 8 weeks post-implantation. Our results are in line with the other published series of Amulet device implants, in which the prevalence of thrombi on follow-up imaging ranged from 0% to 4% (3).
This discrepancy between the findings of Sedaghat et al. (1) and other published series could simply be explained by statistical fluctuation, given the low number of patients. However, a genuine reason for the higher prevalence of thrombus in their patients might be found in their observation that thrombus was associated with incomplete coverage of the ridge between the LAA and the left upper pulmonary vein. In our experience (2), and that of others (3), intraprocedural echocardiography (either transesophageal or intracardiac) is invaluable in helping achieve complete LAA occlusion. The mere use of fluoroscopy, even in a biplane lab, cannot provide the level of detail of LAA anatomy contributed by echocardiography (4,5). It is notable that Sedaghat et al. (1) do not mention the use of echocardiography to guide device implantation in their methods. However, given that their procedures were all performed under conscious sedation and with an average procedure duration of <40 min, it is highly unlikely that transesophageal echocardiogram was used.
Furthermore, Sedaghat et al. (1) recognized the small size of their study population, but they did attempt to compare features of the 4 patients with thrombi with the 20 patients without, concluding that “our analysis indicates a multifactorial cause of device-related thrombus with the Amulet occluder device.” We would tend to agree with their initial observation and point out the inherent limitations of engaging in subgroup comparisons with such small numbers.
We thank Sedaghat et al. (1) for sharing their experience, which strongly highlights the critical importance of ensuring complete coverage of the LAA at implantation and the challenge of getting this right without echocardiographic guidance.
Please note: Dr. Gupta is on the proctors’ panel for St. Jude Medical Ltd. for implantation of Amulet devices. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Sedaghat A.,
- Schrikel J.,
- Andrié R.,
- Schueler R.,
- Nickenig G.,
- Hammerstingl C.
- Bartoletti S.,
- Velavan P.,
- Barclay J.,
- et al.
- Masoudi F.A.,
- Calkins H.,
- Kavinsky C.J.,
- et al.