Details of patients who developed LA thrombi at repeat
ablation
The time to repeat ablation in the three patients who developed thrombi
was 1,449, 515, and 224 days after the initial session (Table 4). All
patients underwent TEE before the first session. Patient 1 was a
44-year-old man with paroxysmal AF. He had a recurrence 6 months after
the first session, but antiarrhythmic drug administration was able to
suppress the AF occurrence thereafter. Anticoagulation, warfarin was
discontinued with reference to the low-risk profile of this patient
(CHADS2 score 0). Three years later, he returned to our
hospital because of the frequent occurrence of AF and underwent a repeat
session. Apixaban was administered alternatively prior to the procedure.
TEE showed a thrombus attached to the LAA wall with a significant grade
2 SEC. Patient 2 was a 38-year-old man with persistent AF. He had a
history of heart failure with reduced LVEF 33% before the first session
and a history of LA thrombus prior to the initial session. After
successful first ablation, sinus rhythm was maintained, with a
remarkable improvement in LVEF. However, atrial flutter with a high-rate
ventricular response occurred after 1 year, which could not be
controlled by anti-arrhythmic drugs, and required repeat ablation.
Echocardiography showed a severely impaired LVEF of 19% and dilated LAD
of 40.7 mm, which might be suggestive of tachycardia-induced
cardiomyopathy. Although the patient continued taking dabigatran from
the first session onwards, the TEE performed before the repeat ablation
revealed LAA thrombi with SEC grade 3. The patient had already been
examined by contrast-enhanced CT prior to the repeat ablation and the
absence of LA thrombi was confirmed, but the examination time was 29
days before the procedure. We speculated that the severely decreased
LVEF due to atrial flutter and heart failure may be a possible
explanation for the development of thrombi in this case. Patient 3 was a
62-year-old man with persistent AF. He underwent extensive LA ablation
in addition to PV isolation with administration of apixaban 10 mg at the
initial session; however, AF recurred after 3 months. Before the repeat
ablation, he experienced an intestinal hemorrhage event causing
hospitalization at another facility, and the attending doctor reduced
the dose of apixaban to 5 mg, which was an inappropriate reduced dose,
although recurrence AF persisted. The inappropriately reduced dose in
this case may be a possible reason for the LAA thrombi with a dense
grade 2 SEC. All three patients had no neurological function
abnormalities and no thromboembolic events occurred thereafter.