Author + information
- Alexander Sedaghat, MD and
- Christoph Hammerstingl, MD∗ ()
- ↵∗Department of Cardiology, Heart Center Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
We read with interest the letter by Dr. Bartoletti and colleagues referring to our paper, which has been recently published in JACC: Clinical Electrophysiology (1). The authors report their own experiences with the Amplatzer Amulet device (St. Jude Medical, St. Paul, Minnesota) in a small patient cohort (2) and they found a relevantly lower number of device-related thrombi (DRT). In their letter Bartoletti and colleagues question the reliability of our findings and raise some concerns, to which we are happy to respond.
First, all the left atrial appendage (LAA) occluder in our series was implanted with echocardiographic guidance by use of 3-dimensional transesophageal echocardiography (TEE). The relatively short implantation time of 40 min is not relevantly different to other experienced centers and does not imply the lack of TEE use. In all our cases we aimed for complete coverage of the LAA, which was not possible in a subset of patients with difficult LAA anatomy or prominent left upper pulmonary vein ridge. Therefore, in our opinion, it is inappropriate to interpret that inadequate periprocedural imaging was the predominant factor causing the reported high DRT rate.
Second, we agree with the authors that in general the published rates of DRT with the Amulet devices are lower than in our study and we discussed possible reasons for this obvious discrepancy intensively in our paper. In brief, most reported findings are based on transthoracic echocardiography performed in small patient cohorts and transthoracic echocardiography is not the gold standard for thrombus detection in the left atrium. Additionally, most data on the Amulet device have been collected from retrospective registries implying a relevant selection bias, and prospective studies with this system are scarce. Although we acknowledge that statistical fluctuation may have played a role in the relatively high incidence, our results from this prospective study with systematic TEE examinations are in concordance with an earlier study published by Plicht et al. (3).
Third, even if Dr. Bartoletti and colleagues had a similar clinical risk profile (CHA2DS2VASc [Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, Prior stroke or transient ischemic attack or thromboembolism, Vascular disease, Age 65 to 74 years, Sex]), altered LA hemodynamics seem of equipotent importance in this setting. This issue was reflected by the high incidence of previous LAA thrombi in the subcohort of patients with DRT. Therefore, we would like to encourage Bartoletti and colleagues to quantify the severity of spontaneous LA echo contrast, LAA peak emptying velocities, and left ventricular ejection fraction in this context. These are established risk factors for the development of LA thrombi and according to our reported experience and patients with impaired LA hemodynamics may therefore be prone to thrombus formation with the insertion of extraneous materials such as an occluder device.
Finally, we felt the necessity to report our results—despite from a small patient cohort—because we found a surprising high incidence of DRT even with the recommended dual antiplatelet therapy. This finding is of relevant importance for daily clinical practice because the optimal anticoagulant or antiplatelet regimen after LAA closure in general, but especially with the Amulet device, remains to be defined and evidence from prospective studies is lacking. As a note of caution, we would like to emphasize that vitamin K antagonist treatment is mandatory after insertion of the Watchman device (Boston Scientific, Marlborough, Massachusetts), which up to now remains the only system that has been tested in a prospective randomized study (4). Furthermore, available evidence has shown impressively that antiplatelet therapy ineffectively protects from cardioembolic stroke in atrial fibrillation patients (5). Therefore, our results underline the unmet need for a prospective study evaluating the optimal anticoagulant regimen after LAA occlusion with different devices. As a consequence of our findings, we encourage all colleagues to perform close TEE follow-up in patients at high thromboembolic risk undergoing LAA occlusion with the Amulet device followed by antiplatelet therapy, especially when optimal occlusion of the LAA at the level of the ostium could not be achieved.
Please note: The 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.
- Plicht B.,
- Konorza T.F.,
- Kahlert P.,
- et al.