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- Karlheinz Seidl, MD, FESC* ()
This is in reply to the communication by Manning and colleagues regarding our manuscript “Embolic Events in Patients With Atrial fibrillation: Value of Transesopageal Echocardiography to Guide DC-Cardioversion” (1).
In accordance with you, we believe that clinical thromboembolism after direct current (DC) cardioversion is related both to migration of thrombi present at the time of cardioversion and to the formation and migration of thrombi in the postcardioversion period.
Our study was a prospective single-center observational study designed on an intention-to-cardiovert basis. During the first two years, patients were treated according to recommendations of the American College of Chest Physicians. In these patients no transesophageal echocardiography (TEE) was performed.
In our opinion we would have detected a similar proportion of left atrial thrombl in these patients. In patients in whom a TEE was performed, all patients with evidence of thrombi were not cardioverted. Patients in the TEE group were older and more often had organic heart disease, impaired left ventricular function, episodes of atrial fibrillation lasting longer than 48 h, and a larger left atrium. However, all these differences were minor and, in our opinion, not clinically relevant. A similar prevalence of thrombi like in the TEE-guided group should be expected in the conventional treatment group. These patients were not excluded from cardioversion, because they were not identified. Nevertheless, the embolic rate was similar.
One might argue that, in our study group (1), patients in the conventional group differed from those in the TEE-guided group. However, when comparing the patient group in the conventional arms of the ACUTE study (2)with our patients in the TEE-guided group, no major difference was observed. This supports the hypothesis that the prevalence of thrombi is about 7% in patients after at least three weeks of effective anticoagulation.
Because this was a single-center observational study, I clearly state that randomized studies evaluating this issue are needed. With knowledge of this in mind, we did not conclude that TEE-guided electrical cardioversion does not reduce the embolic risk; rather, we conclude that our study mayhave two clinical implications. First, TEE before DC cardioversion is not needed in patients with effective anticoagulation at least three weeks before cardioversion, and, second, if TEE is performed early, more thrombi will be detected and more patients will be excluded from cardioversion. However, in patients with a normal TEE study, early cardioversion can be performed safely. The impact of thrombi detected during TEE on long-term outcome must be evaluated.
- American College of Cardiology Foundation
- Seidl K.,
- Rameken M.,
- Drögemüller A.,
- et al.
- Assessment of Cardioversion Using Transesophageal Echocardiography Investigators,
- Klein A.L.,
- Grimm A.A.,
- Murray A.D.,
- et al.