Building the Case for 3D Angiography Alone in LAA Occlusion

Patrice Wendling

January 19, 2018

Left atrial appendage (LAA) occlusion guided by three-dimensional (3D) rotational angiography may be a valid alternative to the universally used two-dimensional transesophageal echocardiography (TEE), results of a pilot study suggest.[1]

"The challenge we face with TEE is not that it's particularly hard— it's not, it's relatively straightforward to do, but sometimes you feel cheated by TEE," lead author, Dr Tom De Potter (OLV Hospital, Aalst, Belgium), told | Medscape Cardiology.

"You get a number, a measurement, and then you look with your eyes at what you see on the x-ray and say, 'There's no way that can be true.' So, what you typically do is you ignore what the TEE tells you and you oversize the device anyway," he continued.

"Everyone does this. In every registry, you see that operators tend to significantly oversize the devices compared to the official recommendations from the manufacturer," De Potter said. "Of course, we felt in the ideal world if we had decent measurements, this shouldn't have to be the case."

The researchers recently reported that using 3D angiography to measure left atrial volume better predicted atrial fibrillation (AF) recurrence after pulmonary vein isolation than did either TEE or AF history.[2]

The present study, published online as a research letter in the January 22, 2018, issue of JACC Cardiovascular Interventions, included 20 patients undergoing LAA occlusion using 3D rotational angiography and fluoroscopy. TEE was performed as a safety backup, but interventionalists were blinded to the results.

In 19 cases, transseptal puncture, device sizing, deployment, stability, and leak assessment were performed with 3D angiography and fluoroscopy alone. One case was aborted because of access problems due to extreme obesity. No procedures were unblinded to the TEE findings.

A retrospective analysis of the two imaging datasets revealed consistent sizing differences in maximum LAA ostial diameter, with a mean diameter of 21 mm with TEE vs 24.3 mm with 3D angiography (R2 =0.64; P<0.05).

Of special note, device release was never attempted in one patient because the LAA ostium proved too large for occlusion with even the largest device. In this patient, maximum ostial diameter by TEE was 27 mm, suggesting an anatomy suitable for implant, whereas 3D angiography identified the case as nonimplantable with a maximum diameter of 30.5 mm, as validated by device unsheathing and confirmation of inadequate stability.

"The 3D angio will universally give you a larger value ostial diameter as compared with TEE, which is an important takeaway message," De Potter said. "Because A, potentially TEE is wrong, which I can't prove but at least it's possible; and B, it's a potential explanation for why so many procedures end up with oversized devices because the TEE might be systematically undersizing the ostial diameter."

For patients, the potential for 3D angiography may also allow them to forego general anesthesia, which is typically used when TEE is performed.

There were no safety issues during the procedure and no new symptoms reported at 6 weeks' follow-up.

Peridevice flow was detected in five patients on follow-up TEE, but these were "clinically irrelevant" and did not lead to a change in management, according to the researchers. No thrombus or device dislodgement was observed.

Still, De Potter cautioned against overinterpreting the data, noting that the sample size was small and the results achieved at a high-volume center that was highly experienced in 3D angiography.

So far, the team has used 3D angiography alongside TEE in more than 100 LAA occlusion cases without having to revert to TEE in any. A protocol for a larger, multicenter study is being devised to determine whether a workflow without direct TEE feedback is feasible, he said.

The study was funded by a research grant from Boston Scientific. The investigators have disclosed no relevant financial relationships.

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